Check for o1 instead of o1-preview for the o1 family

This reverts commit ffcaa23511.

.env.example

@@ -5,12 +5,21 @@
 # All values have reasonable defaults, so you only need to change the ones you
 # want to override.
 
+# Use production mode unless you are developing locally.
+NODE_ENV=production
+
+# Detail level of diagnostic logging. (trace | debug | info | warn | error)
+# LOG_LEVEL=info
+
 # ------------------------------------------------------------------------------
 # General settings:
 
 # The title displayed on the info page.
 # SERVER_TITLE=Coom Tunnel
 
+# The route name used to proxy requests to APIs, relative to the Web site root.
+# PROXY_ENDPOINT_ROUTE=/proxy
+
 # Text model requests allowed per minute per user.
 # TEXT_MODEL_RATE_LIMIT=4
 # Image model requests allowed per minute per user.
@@ -18,53 +27,91 @@
 
 # Max number of context tokens a user can request at once.
 # Increase this if your proxy allow GPT 32k or 128k context
-# MAX_CONTEXT_TOKENS_OPENAI=16384
+# MAX_CONTEXT_TOKENS_OPENAI=32768
+# MAX_CONTEXT_TOKENS_ANTHROPIC=32768
 
 # Max number of output tokens a user can request at once.
-# MAX_OUTPUT_TOKENS_OPENAI=400
-# MAX_OUTPUT_TOKENS_ANTHROPIC=400
+# MAX_OUTPUT_TOKENS_OPENAI=1024
+# MAX_OUTPUT_TOKENS_ANTHROPIC=1024
 
 # Whether to show the estimated cost of consumed tokens on the info page.
 # SHOW_TOKEN_COSTS=false
 
 # Whether to automatically check API keys for validity.
-# Note: CHECK_KEYS is disabled by default in local development mode, but enabled
-# by default in production mode.
+# Disabled by default in local development mode, but enabled in production.
 # CHECK_KEYS=true
 
 # Which model types users are allowed to access.
 # The following model families are recognized:
-# turbo | gpt4 | gpt4-32k | gpt4-turbo | dall-e | claude | gemini-pro | mistral-tiny | mistral-small | mistral-medium | aws-claude | azure-turbo | azure-gpt4 | azure-gpt4-32k | azure-gpt4-turbo
-# By default, all models are allowed except for 'dall-e'. To allow DALL-E image
-# generation, uncomment the line below and add 'dall-e' to the list.
-# ALLOWED_MODEL_FAMILIES=turbo,gpt4,gpt4-32k,gpt4-turbo,claude,gemini-pro,mistral-tiny,mistral-small,mistral-medium,aws-claude,azure-turbo,azure-gpt4,azure-gpt4-32k,azure-gpt4-turbo
+# turbo | gpt4 | gpt4-32k | gpt4-turbo | gpt4o | o1 | dall-e | claude
+# | claude-opus | gemini-flash | gemini-pro | gemini-ultra | mistral-tiny |
+# | mistral-small | mistral-medium | mistral-large | aws-claude |
+# | aws-claude-opus | gcp-claude | gcp-claude-opus | azure-turbo | azure-gpt4
+# | azure-gpt4-32k | azure-gpt4-turbo | azure-gpt4o | azure-o1 | azure-dall-e
 
+# By default, all models are allowed except for dall-e and o1.
+# To allow DALL-E image generation, uncomment the line below and add 'dall-e' or
+# 'azure-dall-e' to the list of allowed model families.
+# ALLOWED_MODEL_FAMILIES=turbo,gpt4,gpt4-32k,gpt4-turbo,gpt4o,claude,claude-opus,gemini-flash,gemini-pro,gemini-ultra,mistral-tiny,mistral-small,mistral-medium,mistral-large,aws-claude,aws-claude-opus,gcp-claude,gcp-claude-opus,azure-turbo,azure-gpt4,azure-gpt4-32k,azure-gpt4-turbo,azure-gpt4o
+
+# Which services can be used to process prompts containing images via multimodal
+# models. The following services are recognized:
+# openai | anthropic | aws | gcp | azure | google-ai | mistral-ai
+# Do not enable this feature unless all users are trusted, as you will be liable
+# for any user-submitted images containing illegal content.
+# By default, no image services are allowed and image prompts are rejected.
+# ALLOWED_VISION_SERVICES=
+
+# Whether prompts should be logged to Google Sheets.
+# Requires additional setup. See `docs/google-sheets.md` for more information.
+# PROMPT_LOGGING=false
+
+# Specifies the number of proxies or load balancers in front of the server.
+# For Cloudflare or Hugging Face deployments, the default of 1 is correct.
+# For any other deployments, please see config.ts as the correct configuration
+# depends on your setup. Misconfiguring this value can result in problems
+# accurately tracking IP addresses and enforcing rate limits.
+# TRUSTED_PROXIES=1
+
+# Whether cookies should be set without the Secure flag, for hosts that don't
+# support SSL. True by default in development, false in production.
+# USE_INSECURE_COOKIES=false
+
+# Reorganizes requests in the queue according to their token count, placing
+# larger prompts further back. The penalty is determined by (promptTokens *
+# TOKENS_PUNISHMENT_FACTOR). A value of 1.0 adds one second per 1000 tokens.
+# When there is no queue or it is very short, the effect is negligible (this
+# setting only reorders the queue, it does not artificially delay requests).
+# TOKENS_PUNISHMENT_FACTOR=0.0
+
+# Captcha verification settings. Refer to docs/pow-captcha.md for guidance.
+# CAPTCHA_MODE=none
+# POW_TOKEN_HOURS=24
+# POW_TOKEN_MAX_IPS=2
+# POW_DIFFICULTY_LEVEL=low
+# POW_CHALLENGE_TIMEOUT=30
+
+# -------------------------------------------------------------------------------
+# Blocking settings:
+# Allows blocking requests depending on content, referers, or IP addresses.
+# This is a convenience feature; if you need more robust functionality it is
+# highly recommended to put this application behind nginx or Cloudflare, as they
+# will have better performance.
+
+# IP addresses or CIDR blocks from which requests will be blocked.
+# IP_BLACKLIST=10.0.0.1/24
 # URLs from which requests will be blocked.
 # BLOCKED_ORIGINS=reddit.com,9gag.com
 # Message to show when requests are blocked.
 # BLOCK_MESSAGE="You must be over the age of majority in your country to use this service."
 # Destination to redirect blocked requests to.
 # BLOCK_REDIRECT="https://roblox.com/"
-
-# Comma-separated list of phrases that will be rejected. Only whole words are matched.
-# Surround phrases with quotes if they contain commas.
-# Avoid short or common phrases as this tests the entire prompt.
+# Comma-separated list of phrases that will be rejected. Surround phrases with
+# quotes if they contain commas. You can use regular expression tokens.
+# Avoid overly broad phrases as will trigger on any match in the entire prompt.
 # REJECT_PHRASES="phrase one,phrase two,"phrase three, which has a comma",phrase four"
 # Message to show when requests are rejected.
-# REJECT_MESSAGE="This content violates /aicg/'s acceptable use policy."
-
-# Whether prompts should be logged to Google Sheets.
-# Requires additional setup. See `docs/google-sheets.md` for more information.
-# PROMPT_LOGGING=false
-
-# The port to listen on.
-# PORT=7860
-
-# Whether cookies should be set without the Secure flag, for hosts that don't support SSL.
-# USE_INSECURE_COOKIES=false
-
-# Detail level of logging. (trace | debug | info | warn | error)
-# LOG_LEVEL=info
+# REJECT_MESSAGE="You can't say that here."
 
 # ------------------------------------------------------------------------------
 # Optional settings for user management, access control, and quota enforcement:
@@ -85,43 +132,60 @@
 # ALLOW_NICKNAME_CHANGES=true
 
 # Default token quotas for each model family. (0 for unlimited)
-# DALL-E "tokens" are counted at a rate of 100000 tokens per US$1.00 generated,
-# which is similar to the cost of GPT-4 Turbo.
+# Specify as TOKEN_QUOTA_MODEL_FAMILY=value (replacing dashes with underscores).
+# eg. TOKEN_QUOTA_TURBO=0, TOKEN_QUOTA_GPT4=1000000, TOKEN_QUOTA_GPT4_32K=100000
+# "Tokens" for image-generation models are counted at a rate of 100000 tokens
+# per US$1.00 generated, which is similar to the cost of GPT-4 Turbo.
 # DALL-E 3 costs around US$0.10 per image (10000 tokens).
 # See `docs/dall-e-configuration.md` for more information.
-# TOKEN_QUOTA_TURBO=0
-# TOKEN_QUOTA_GPT4=0
-# TOKEN_QUOTA_GPT4_32K=0
-# TOKEN_QUOTA_GPT4_TURBO=0
 # TOKEN_QUOTA_DALL_E=0
-# TOKEN_QUOTA_CLAUDE=0
-# TOKEN_QUOTA_GEMINI_PRO=0
-# TOKEN_QUOTA_AWS_CLAUDE=0
 
 # How often to refresh token quotas. (hourly | daily)
 # Leave unset to never automatically refresh quotas.
 # QUOTA_REFRESH_PERIOD=daily
 
+# -------------------------------------------------------------------------------
+# HTTP agent settings:
+# If you need to change how the proxy makes requests to other servers, such
+# as when checking keys or forwarding users' requests to external services,
+# you can configure an alternative HTTP agent. Otherwise the default OS settings
+# will be used.
+
+# The name of the network interface to use. The first external IPv4 address
+# belonging to this interface will be used for outgoing requests.
+# HTTP_AGENT_INTERFACE=enp0s3
+
+# The URL of a proxy server to use. Supports SOCKS4, SOCKS5, HTTP, and HTTPS.
+# Note that if your proxy server issues a self-signed certificate, you may need
+# NODE_EXTRA_CA_CERTS set to the path to your certificate. You will need to set
+# that variable in your environment, not in this file.
+# HTTP_AGENT_PROXY_URL=http://test:test@127.0.0.1:8000
+
 # ------------------------------------------------------------------------------
 # Secrets and keys:
-# Do not put any passwords or API keys directly in this file.
-# For Huggingface, set them via the Secrets section in your Space's config UI.
+# For Huggingface, set them via the Secrets section in your Space's config UI. Dp not set them in .env.
 # For Render, create a "secret file" called .env using the Environment tab.
 
 # You can add multiple API keys by separating them with a comma.
 # For AWS credentials, separate the access key ID, secret key, and region with a colon.
+# For GCP credentials, separate the project ID, client email, region, and private key with a colon.
 OPENAI_KEY=sk-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
 ANTHROPIC_KEY=sk-ant-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+GOOGLE_AI_KEY=AIzaxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
 # See `docs/aws-configuration.md` for more information, there may be additional steps required to set up AWS.
 AWS_CREDENTIALS=myaccesskeyid:mysecretkey:us-east-1,anotheraccesskeyid:anothersecretkey:us-west-2
 # See `docs/azure-configuration.md` for more information, there may be additional steps required to set up Azure.
 AZURE_CREDENTIALS=azure-resource-name:deployment-id:api-key,another-azure-resource-name:another-deployment-id:another-api-key
+GCP_CREDENTIALS=project-id:client-email:region:private-key
 
 # With proxy_key gatekeeper, the password users must provide to access the API.
 # PROXY_KEY=your-secret-key
 
 # With user_token gatekeeper, the admin password used to manage users.
 # ADMIN_KEY=your-very-secret-key
+# Restrict access to the admin interface to specific IP addresses, specified
+# as a comma-separated list of CIDR ranges.
+# ADMIN_WHITELIST=0.0.0.0/0
 
 # With firebase_rtdb gatekeeper storage, the Firebase project credentials.
 # FIREBASE_KEY=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

.gitignore

@@ -1,8 +1,11 @@
-.env
+.aider*
+.env*
+!.env.vault
 .venv
 .vscode
 .idea
 build
 greeting.md
 node_modules
+
 http-client.private.env.json

.prettierrc

@@ -1,11 +1,10 @@
 {
+  "plugins": ["prettier-plugin-ejs"],
   "overrides": [
     {
-      "files": [
-        "*.ejs"
-      ],
+      "files": "*.ejs",
       "options": {
-        "printWidth": 160,
+        "printWidth": 120,
         "bracketSameLine": true
       }
     }

README.md

@@ -1,42 +1,72 @@
 # OAI Reverse Proxy
-
-Reverse proxy server for the OpenAI and Anthropic APIs. Forwards text generation requests while rejecting administrative/billing requests. Includes optional rate limiting and prompt filtering to prevent abuse.
+Reverse proxy server for various LLM APIs.
 
 ### Table of Contents
-- [What is this?](#what-is-this)
-- [Why?](#why)
-- [Usage Instructions](#setup-instructions)
-  - [Deploy to Huggingface (Recommended)](#deploy-to-huggingface-recommended)
-  - [Deploy to Repl.it (WIP)](#deploy-to-replit-wip)
-- [Local Development](#local-development)
+<!-- TOC -->
+* [OAI Reverse Proxy](#oai-reverse-proxy)
+    * [Table of Contents](#table-of-contents)
+  * [What is this?](#what-is-this)
+  * [Features](#features)
+  * [Usage Instructions](#usage-instructions)
+    * [Personal Use (single-user)](#personal-use-single-user)
+      * [Updating](#updating)
+      * [Local Development](#local-development)
+    * [Self-hosting](#self-hosting)
+  * [Building](#building)
+  * [Forking](#forking)
+<!-- TOC -->
 
 ## What is this?
-If you would like to provide a friend access to an API via keys you own, you can use this to keep your keys safe while still allowing them to generate text with the API. You can also use this if you'd like to build a client-side application which uses the OpenAI or Anthropic APIs, but don't want to build your own backend. You should never embed your real API keys in a client-side application. Instead, you can have your frontend connect to this reverse proxy and forward requests to the downstream service.
+This project allows you to run a reverse proxy server for various LLM APIs.
 
-This keeps your keys safe and allows you to use the rate limiting and prompt filtering features of the proxy to prevent abuse.
-
-## Why?
-OpenAI keys have full account permissions. They can revoke themselves, generate new keys, modify spend quotas, etc. **You absolutely should not share them, post them publicly, nor embed them in client-side applications as they can be easily stolen.**
-
-This proxy only forwards text generation requests to the downstream service and rejects requests which would otherwise modify your account. 
-
----
+## Features
+- [x] Support for multiple APIs
+  - [x] [OpenAI](https://openai.com/)
+  - [x] [Anthropic](https://www.anthropic.com/)
+  - [x] [AWS Bedrock](https://aws.amazon.com/bedrock/)
+  - [x] [Vertex AI (GCP)](https://cloud.google.com/vertex-ai/)
+  - [x] [Google MakerSuite/Gemini API](https://ai.google.dev/)
+  - [x] [Azure OpenAI](https://azure.microsoft.com/en-us/products/ai-services/openai-service)
+- [x] Translation from OpenAI-formatted prompts to any other API, including streaming responses
+- [x] Multiple API keys with rotation and rate limit handling
+- [x] Basic user management
+  - [x] Simple role-based permissions
+  - [x] Per-model token quotas
+  - [x] Temporary user accounts
+- [x] Event audit logging
+- [x] Optional full logging of prompts and completions
+- [x] Abuse detection and prevention
+  - [x] IP address and user token model invocation rate limits
+  - [x] IP blacklists
+  - [x] Proof-of-work challenge for access by anonymous users
 
 ## Usage Instructions
-If you'd like to run your own instance of this proxy, you'll need to deploy it somewhere and configure it with your API keys. A few easy options are provided below, though you can also deploy it to any other service you'd like.
+If you'd like to run your own instance of this server, you'll need to deploy it somewhere and configure it with your API keys. A few easy options are provided below, though you can also deploy it to any other service you'd like if you know what you're doing and the service supports Node.js.
 
-### Deploy to Huggingface (Recommended)
-[See here for instructions on how to deploy to a Huggingface Space.](./docs/deploy-huggingface.md)
-
-### Deploy to Render
-[See here for instructions on how to deploy to Render.com.](./docs/deploy-render.md)
-
-## Local Development
-To run the proxy locally for development or testing, install Node.js >= 18.0.0 and follow the steps below.
-
-1. Clone the repo
-2. Install dependencies with `npm install`
+### Personal Use (single-user)
+If you just want to run the proxy server to use yourself without hosting it for others:
+1. Install [Node.js](https://nodejs.org/en/download/) >= 18.0.0
+2. Clone this repository
 3. Create a `.env` file in the root of the project and add your API keys. See the [.env.example](./.env.example) file for an example.
-4. Start the server in development mode with `npm run start:dev`.
+4. Install dependencies with `npm install`
+5. Run `npm run build`
+6. Run `npm start`
 
-You can also use `npm run start:dev:tsc` to enable project-wide type checking at the cost of slower startup times. `npm run type-check` can be used to run type checking without starting the server.
+#### Updating
+You must re-run `npm install` and `npm run build` whenever you pull new changes from the repository.
+
+#### Local Development
+Use `npm run start:dev` to run the proxy in development mode with watch mode enabled. Use `npm run type-check` to run the type checker across the project.
+
+### Self-hosting
+[See here for instructions on how to self-host the application on your own VPS or local machine and expose it to the internet for others to use.](./docs/self-hosting.md)
+
+**Ensure you set the `TRUSTED_PROXIES` environment variable according to your deployment.** Refer to [.env.example](./.env.example) and [config.ts](./src/config.ts) for more information.
+
+## Building
+To build the project, run `npm run build`. This will compile the TypeScript code to JavaScript and output it to the `build` directory. You should run this whenever you pull new changes from the repository.
+
+Note that if you are trying to build the server on a very memory-constrained (<= 1GB) VPS, you may need to run the build with `NODE_OPTIONS=--max_old_space_size=2048 npm run build` to avoid running out of memory during the build process, assuming you have swap enabled.  The application itself should run fine on a 512MB VPS for most reasonable traffic levels.
+
+## Forking
+If you are forking the repository on GitGud, you may wish to disable GitLab CI/CD or you will be spammed with emails about failed builds due not having any CI runners. You can do this by going to *Settings > General > Visibility, project features, permissions* and then disabling the "CI/CD" feature.

docker/ci/.gitlab-ci.yml

@@ -0,0 +1,21 @@
+stages:
+  - build
+
+build_image:
+  stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [""]
+  script:
+    - |
+      if [ "$CI_COMMIT_REF_NAME" = "main" ]; then
+        TAG="latest"
+      else
+        TAG=$CI_COMMIT_REF_NAME
+      fi
+    - echo "Building image with tag $TAG"
+    - BASE64_AUTH=$(echo -n "$DOCKER_HUB_USERNAME:$DOCKER_HUB_ACCESS_TOKEN" | base64)
+    - echo "{\"auths\":{\"https://index.docker.io/v1/\":{\"auth\":\"$BASE64_AUTH\"}}}" > /kaniko/.docker/config.json
+    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/docker/ci/Dockerfile --destination docker.io/khanonci/oai-reverse-proxy:$TAG --build-arg CI_COMMIT_REF_NAME=$CI_COMMIT_REF_NAME --build-arg CI_COMMIT_SHA=$CI_COMMIT_SHA --build-arg CI_PROJECT_PATH=$CI_PROJECT_PATH
+  only:
+    - main

docker/ci/Dockerfile

@@ -0,0 +1,22 @@
+FROM node:18-bullseye-slim
+
+WORKDIR /app
+COPY . .
+
+RUN npm ci
+RUN npm run build
+RUN npm prune --production
+
+EXPOSE 7860
+ENV PORT=7860
+ENV NODE_ENV=production
+
+ARG CI_COMMIT_REF_NAME
+ARG CI_COMMIT_SHA
+ARG CI_PROJECT_PATH
+
+ENV GITGUD_BRANCH=$CI_COMMIT_REF_NAME
+ENV GITGUD_COMMIT=$CI_COMMIT_SHA
+ENV GITGUD_PROJECT=$CI_PROJECT_PATH
+
+CMD [ "npm", "start" ]

docker/docker-compose-selfhost.yml

@@ -0,0 +1,17 @@
+# Before running this, create a .env and greeting.md file.
+# Refer to .env.example for the required environment variables.
+# User-generated content is stored in the data directory.
+# When self-hosting, it's recommended to run this behind a reverse proxy like
+# nginx or Caddy to handle SSL/TLS and rate limiting. Refer to
+# docs/self-hosting.md for more information and an example nginx config.
+version: '3.8'
+services:
+  oai-reverse-proxy:
+    image: khanonci/oai-reverse-proxy:latest
+    ports:
+      - "127.0.0.1:7860:7860"
+    env_file:
+      - ./.env
+    volumes:
+      - ./greeting.md:/app/greeting.md
+      - ./data:/app/data

docker/render/Dockerfile

@@ -17,9 +17,8 @@ ARG GREETING_URL
 RUN if [ -n "$GREETING_URL" ]; then \
     curl -sL "$GREETING_URL" > greeting.md; \
     fi
-COPY package*.json greeting.md* ./
-RUN npm install
 COPY . .
+RUN npm install
 RUN npm run build
 RUN --mount=type=secret,id=_env,dst=/etc/secrets/.env cat /etc/secrets/.env >> .env
 EXPOSE 10000

docs/aws-configuration.md

@@ -45,7 +45,7 @@ You can also request Claude Instant, but support for this isn't fully implemente
 ### Supported model IDs
 Users can send these model IDs to the proxy to invoke the corresponding models.
 - **Claude**
-  - `anthropic.claude-v1` (~18k context, claude 1.3)
+  - `anthropic.claude-v1` (~18k context, claude 1.3 -- EOL 2024-02-28)
   - `anthropic.claude-v2` (~100k context, claude 2.0)
   - `anthropic.claude-v2:1` (~200k context, claude 2.1)
 - **Claude Instant**

docs/deploy-huggingface.md

@@ -1,5 +1,7 @@
 # Deploy to Huggingface Space
 
+**⚠️ This method is no longer recommended.  Please use the [self-hosting instructions](./self-hosting.md) instead.**
+
 This repository can be deployed to a [Huggingface Space](https://huggingface.co/spaces).  This is a free service that allows you to run a simple server in the cloud.  You can use it to safely share your OpenAI API key with a friend.
 
 ### 1. Get an API key

docs/deploy-render.md

@@ -1,4 +1,7 @@
 # Deploy to Render.com
+
+**⚠️ This method is no longer supported or recommended and may not work.  Please use the [self-hosting instructions](./self-hosting.md) instead.**
+
 Render.com offers a free tier that includes 750 hours of compute time per month.  This is enough to run a single proxy instance 24/7.  Instances shut down after 15 minutes without traffic but start up again automatically when a request is received.  You can use something like https://app.checklyhq.com/ to ping your proxy every 15 minutes to keep it alive.
 
 ### 1. Create account
@@ -28,6 +31,8 @@ The service will be created according to the instructions in the `render.yaml` f
   - For example, `OPENAI_KEY=sk-abc123`.
 - Click **Save Changes**.
 
+**IMPORTANT:** Set `TRUSTED_PROXIES=3`, otherwise users' IP addresses will not be recorded correctly (the server will see the IP address of Render's load balancer instead of the user's real IP address).
+
 The service will automatically rebuild and deploy with the new environment variables.  This will take a few minutes.  The link to your deployed proxy will appear at the top of the page.
 
 If you want to change the URL, go to the **Settings** tab of your Web Service and click the **Edit** button next to **Name**.  You can also set a custom domain, though I haven't tried this yet.

docs/gcp-configuration.md

@@ -0,0 +1,35 @@
+# Configuring the proxy for Vertex AI (GCP)
+
+The proxy supports GCP models via the `/proxy/gcp/claude` endpoint. There are a few extra steps necessary to use GCP compared to the other supported APIs.
+
+- [Setting keys](#setting-keys)
+- [Setup Vertex AI](#setup-vertex-ai)
+- [Supported model IDs](#supported-model-ids)
+
+## Setting keys
+
+Use the `GCP_CREDENTIALS` environment variable to set the GCP API keys.
+
+Like other APIs, you can provide multiple keys separated by commas. Each GCP key, however, is a set of credentials including the project id, client email, region and private key. These are separated by a colon (`:`).
+
+For example:
+
+```
+GCP_CREDENTIALS=my-first-project:xxx@yyy.com:us-east5:-----BEGIN PRIVATE KEY-----xxx-----END PRIVATE KEY-----,my-first-project2:xxx2@yyy.com:us-east5:-----BEGIN PRIVATE KEY-----xxx-----END PRIVATE KEY-----
+```
+
+## Setup Vertex AI
+1. Go to [https://cloud.google.com/vertex-ai](https://cloud.google.com/vertex-ai) and sign up for a GCP account. ($150 free credits without credit card or $300 free credits with credit card, credits expire in 90 days)
+2. Go to [https://console.cloud.google.com/marketplace/product/google/aiplatform.googleapis.com](https://console.cloud.google.com/marketplace/product/google/aiplatform.googleapis.com) to enable Vertex AI API.
+3. Go to [https://console.cloud.google.com/vertex-ai](https://console.cloud.google.com/vertex-ai) and navigate to Model Garden to apply for access to the Claude models.
+4. Create a [Service Account](https://console.cloud.google.com/projectselector/iam-admin/serviceaccounts/create?walkthrough_id=iam--create-service-account#step_index=1) , and make sure to grant the role of "Vertex AI User" or "Vertex AI Administrator".
+5. On the service account page you just created, create a new key and select "JSON". The JSON file will be downloaded automatically.
+6. The required credential is in the JSON file you just downloaded.
+
+## Supported model IDs
+Users can send these model IDs to the proxy to invoke the corresponding models.
+- **Claude**
+  - `claude-3-haiku@20240307`
+  - `claude-3-sonnet@20240229`
+  - `claude-3-opus@20240229`
+  - `claude-3-5-sonnet@20240620`

docs/pow-captcha.md

@@ -0,0 +1,135 @@
+# Proof-of-work Verification
+
+You can require users to complete a proof-of-work before they can access the
+proxy. This can increase the cost of denial of service attacks and slow down
+automated abuse.
+
+When configured, users access the challenge UI and request a token. The server
+sends a challenge to the client, which asks the user's browser to find a 
+solution to the challenge that meets a certain constraint (the difficulty
+level). Once the user has found a solution, they can submit it to the server
+and get a user token valid for a period you specify.
+
+The proof-of-work challenge uses the argon2id hash function.
+
+## Configuration
+
+To enable proof-of-work verification, set the following environment variables:
+
+```
+GATEKEEPER=user_token
+CAPTCHA_MODE=proof_of_work
+# Validity of the token in hours
+POW_TOKEN_HOURS=24
+# Max number of IPs that can use a user_token issued via proof-of-work
+POW_TOKEN_MAX_IPS=2
+# The difficulty level of the proof-of-work challenge. You can use one of the
+# predefined levels specified below, or you can specify a custom number of
+# expected hash iterations.
+POW_DIFFICULTY_LEVEL=low
+# The time limit for solving the challenge, in minutes
+POW_CHALLENGE_TIMEOUT=30
+```
+
+## Difficulty Levels
+
+The difficulty level controls how long, on average, it will take for a user to
+solve the proof-of-work challenge. Due to randomness, the actual time can very
+significantly; lucky users may solve the challenge in a fraction of the average
+time, while unlucky users may take much longer.
+
+The difficulty level doesn't affect the speed of the hash function itself, only
+the number of hashes that will need to be computed. Therefore, the time required
+to complete the challenge scales linearly with the difficulty level's iteration
+count.
+
+You can adjust the difficulty level while the proxy is running from the admin
+interface.
+
+Be aware that there is a time limit for solving the challenge, by default set to
+30 minutes. Above 'high' difficulty, you will probably need to increase the time
+limit or it will be very hard for users with slow devices to find a solution
+within the time limit.
+
+### Low
+
+- Average of 200 iterations required
+- Default setting.
+
+### Medium
+
+- Average of 900 iterations required
+
+### High
+
+- Average of 1900 iterations required
+
+### Extreme
+
+- Average of 4000 iterations required
+- Not recommended unless you are expecting very high levels of abuse
+- May require increasing `POW_CHALLENGE_TIMEOUT`
+
+### Custom
+
+Setting `POW_DIFFICULTY_LEVEL` to an integer will use that number of iterations
+as the difficulty level.
+
+## Other challenge settings
+
+- `POW_CHALLENGE_TIMEOUT`: The time limit for solving the challenge, in minutes.
+  Default is 30.
+- `POW_TOKEN_HOURS`: The period of time for which a user token issued via proof-
+  of-work can be used. Default is 24 hours. Starts when the challenge is solved.
+- `POW_TOKEN_MAX_IPS`: The maximum number of unique IPs that can use a single
+  user token issued via proof-of-work. Default is 2.
+- `POW_TOKEN_PURGE_HOURS`: The period of time after which an expired user token
+  issued via proof-of-work will be removed from the database. Until it is
+  purged, users can refresh expired tokens by completing a half-difficulty
+  challenge. Default is 48 hours.
+- `POW_MAX_TOKENS_PER_IP`: The maximum number of active user tokens that can
+  be associated with a single IP address. After this limit is reached, the
+  oldest token will be forcibly expired when a new token is issued. Set to 0
+  to disable this feature. Default is 0.
+
+## Custom argon2id parameters
+
+You can set custom argon2id parameters for the proof-of-work challenge.
+Generally, you should not need to change these unless you have a specific
+reason to do so.
+
+The listed values are the defaults.
+
+```
+ARGON2_TIME_COST=8
+ARGON2_MEMORY_KB=65536
+ARGON2_PARALLELISM=1
+ARGON2_HASH_LENGTH=32
+```
+
+Increasing parallelism will not do much except increase memory consumption for
+both the client and server, because browser proof-of-work implementations are
+single-threaded. It's better to increase the time cost if you want to increase
+the difficulty.
+
+Increasing memory too much may cause memory exhaustion on some mobile devices,
+particularly on iOS due to the way Safari handles WebAssembly memory allocation.
+
+## Tested hash rates
+
+These were measured with the default argon2id parameters listed above. These
+tests were not at all scientific so take them with a grain of salt.
+
+Safari does not like large WASM memory usage, so concurrency is limited to 4 to
+avoid overallocating memory on mobile WebKit browsers. Thermal throttling can
+also significantly reduce hash rates on mobile devices.
+
+- Intel Core i9-13900K (Chrome): 33-35 H/s
+- Intel Core i9-13900K (Firefox): 29-32 H/s
+- Intel Core i9-13900K (Chrome, in VM limited to 4 cores): 12.2 - 13.0 H/s
+- iPad Pro (M2) (Safari, 6 workers): 8.0 - 10 H/s
+  - Thermal throttles early. 8 cores is normal concurrency, but unstable.
+- iPhone 15 Pro Max (Safari): 4.0 - 4.6 H/s
+- Samsung Galaxy S10e (Chrome): 3.6 - 3.8 H/s
+  - This is a 2019 phone almost matching an iPhone five years newer because of
+    bad Safari performance.

docs/self-hosting.md

@@ -0,0 +1,150 @@
+# Quick self-hosting guide
+
+Temporary guide for self-hosting. This will be improved in the future to provide more robust instructions and options. Provided commands are for Ubuntu.
+
+This uses prebuilt Docker images for convenience. If you want to make adjustments to the code you can instead clone the repo and follow the Local Development guide in the [README](../README.md).
+
+## Table of Contents
+- [Requirements](#requirements)
+- [Running the application](#running-the-application)
+- [Setting up a reverse proxy](#setting-up-a-reverse-proxy)
+  - [trycloudflare](#trycloudflare)
+  - [nginx](#nginx)
+    - [Example basic nginx configuration (no SSL)](#example-basic-nginx-configuration-no-ssl)
+    - [Example with Cloudflare SSL](#example-with-cloudflare-ssl)
+- [Updating/Restarting the application](#updatingrestarting-the-application)
+
+## Requirements
+
+- Docker
+- Docker Compose
+- A VPS with at least 512MB of RAM (1GB recommended)
+- A domain name
+
+If you don't have a VPS and domain name you can use TryCloudflare to set up a temporary URL that you can share with others. See [trycloudflare](#trycloudflare) for more information.
+
+## Running the application
+
+- Install Docker and Docker Compose
+- Create a new directory for the application
+  - This will contain your .env file, greeting file, and any user-generated files
+- Execute the following commands:
+  - ```
+    touch .env
+    touch greeting.md
+    echo "OPENAI_KEY=your-openai-key" >> .env
+    curl https://gitgud.io/khanon/oai-reverse-proxy/-/raw/main/docker/docker-compose-selfhost.yml -o docker-compose.yml
+    ```
+  - You can set further environment variables and keys in the `.env` file. See [.env.example](../.env.example) for a list of available options.
+  - You can set a custom greeting in `greeting.md`. This will be displayed on the homepage.
+- Run `docker compose up -d`
+
+You can check logs with `docker compose logs -n 100 -f`.
+
+The provided docker-compose file listens on port 7860 but binds to localhost only. You should use a reverse proxy to expose the application to the internet as described in the next section.
+
+## Setting up a reverse proxy
+
+Rather than exposing the application directly to the internet, it is recommended to set up a reverse proxy. This will allow you to use HTTPS and add additional security measures.
+
+### trycloudflare
+
+This will give you a temporary (72 hours) URL that you can use to let others connect to your instance securely, without having to set up a reverse proxy. If you are running the server on your home network, this is probably the best option.
+- Install `cloudflared` following the instructions at [try.cloudflare.com](https://try.cloudflare.com/).
+- Run `cloudflared tunnel --url http://localhost:7860`
+- You will be given a temporary URL that you can share with others.
+
+If you have a VPS, you should use a proper reverse proxy like nginx instead for a more permanent solution which will allow you to use your own domain name, handle SSL, and add additional security/anti-abuse measures.
+
+### nginx
+
+First, install nginx.
+- `sudo apt update && sudo apt install nginx`
+
+#### Example basic nginx configuration (no SSL)
+
+- `sudo nano /etc/nginx/sites-available/oai.conf`
+  - ```
+    server {
+        listen 80;
+        server_name example.com;
+    
+        location / {
+            proxy_pass http://localhost:7860;
+        }
+    }
+    ```
+  - Replace `example.com` with your domain name.
+  - Ctrl+X to exit, Y to save, Enter to confirm.
+- `sudo ln -s /etc/nginx/sites-available/oai.conf /etc/nginx/sites-enabled`
+- `sudo nginx -t`
+  - This will check the configuration file for errors.
+- `sudo systemctl restart nginx`
+  - This will restart nginx and apply the new configuration.
+
+#### Example with Cloudflare SSL
+
+This allows you to use a self-signed certificate on the server, and have Cloudflare handle client SSL. You need to have a Cloudflare account and have your domain set up with Cloudflare already, pointing to your server's IP address.
+
+- Set Cloudflare to use Full SSL mode. Since we are using a self-signed certificate, don't use Full (strict) mode.
+- Create a self-signed certificate:
+  - `openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/ssl/private/nginx-selfsigned.key -out /etc/ssl/certs/nginx-selfsigned.crt`
+- `sudo nano /etc/nginx/sites-available/oai.conf`
+  - ```
+    server {
+        listen 443 ssl;
+        server_name yourdomain.com www.yourdomain.com;
+    
+        ssl_certificate /etc/ssl/certs/nginx-selfsigned.crt;
+        ssl_certificate_key /etc/ssl/private/nginx-selfsigned.key;
+    
+        # Only allow inbound traffic from Cloudflare
+        allow 173.245.48.0/20;
+        allow 103.21.244.0/22;
+        allow 103.22.200.0/22;
+        allow 103.31.4.0/22;
+        allow 141.101.64.0/18;
+        allow 108.162.192.0/18;
+        allow 190.93.240.0/20;
+        allow 188.114.96.0/20;
+        allow 197.234.240.0/22;
+        allow 198.41.128.0/17;
+        allow 162.158.0.0/15;
+        allow 104.16.0.0/13;
+        allow 104.24.0.0/14;
+        allow 172.64.0.0/13;
+        allow 131.0.72.0/22;
+        deny all;
+    
+        location / {
+            proxy_pass http://localhost:7860;
+            proxy_http_version 1.1;
+            proxy_set_header Upgrade $http_upgrade;
+            proxy_set_header Connection 'upgrade';
+            proxy_set_header Host $host;
+            proxy_cache_bypass $http_upgrade;
+        }
+    
+        ssl_protocols TLSv1.2 TLSv1.3;
+        ssl_ciphers 'ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256';
+        ssl_prefer_server_ciphers on;
+        ssl_session_cache shared:SSL:10m;
+    }
+    ```
+  - Replace `yourdomain.com` with your domain name.
+  - Ctrl+X to exit, Y to save, Enter to confirm.
+- `sudo ln -s /etc/nginx/sites-available/oai.conf /etc/nginx/sites-enabled`
+
+## Updating/Restarting the application
+
+After making an .env change, you need to restart the application for it to take effect.
+
+- `docker compose down`
+- `docker compose up -d`
+
+To update the application to the latest version:
+
+- `docker compose pull`
+- `docker compose down`
+- `docker compose up -d`
+- `docker image prune -f`

docs/user-management.md

@@ -12,6 +12,7 @@ Several of these features require you to set secrets in your environment. If usi
   - [Memory](#memory)
   - [Firebase Realtime Database](#firebase-realtime-database)
     - [Firebase setup instructions](#firebase-setup-instructions)
+- [Whitelisting admin IP addresses](#whitelisting-admin-ip-addresses)
 
 ## No user management (`GATEKEEPER=none`)
 
@@ -61,3 +62,12 @@ To use Firebase Realtime Database to persist user data, set the following enviro
 8. Set `GATEKEEPER_STORE` to `firebase_rtdb` in your environment if you haven't already.
 
 The proxy server will attempt to connect to your Firebase Realtime Database at startup and will throw an error if it cannot connect. If you see this error, check that your `FIREBASE_RTDB_URL` and `FIREBASE_KEY` secrets are set correctly.
+
+## Whitelisting admin IP addresses
+You can add your own IP ranges to the `ADMIN_WHITELIST` environment variable for additional security.
+
+You can provide a comma-separated list containing individual IPv4 or IPv6 addresses, or CIDR ranges.
+
+To whitelist an entire IP range, use CIDR notation. For example, `192.168.0.1/24` would whitelist all addresses from `192.168.0.0` to `192.168.0.255`.
+
+To disable the whitelist, set `ADMIN_WHITELIST=0.0.0.0/0,::0`, which will allow access from any IPv4 or IPv6 address. This is the default behavior.

package.json

@@ -4,10 +4,12 @@
   "description": "Reverse proxy for the OpenAI API",
   "scripts": {
     "build": "tsc && copyfiles -u 1 src/**/*.ejs build",
+    "database:migrate": "ts-node scripts/migrate.ts",
+    "postinstall": "patch-package",
     "prepare": "husky install",
-    "start": "node build/server.js",
+    "start": "node --trace-deprecation --trace-warnings build/server.js",
     "start:dev": "nodemon --watch src --exec ts-node --transpile-only src/server.ts",
-    "start:replit": "tsc && node build/server.js",
+    "start:debug": "ts-node --inspect --transpile-only src/server.ts",
     "start:watch": "nodemon --require source-map-support/register build/server.js",
     "type-check": "tsc --noEmit"
   },
@@ -18,40 +20,53 @@
   "license": "MIT",
   "dependencies": {
     "@anthropic-ai/tokenizer": "^0.0.4",
-    "@aws-crypto/sha256-js": "^5.1.0",
-    "@smithy/protocol-http": "^3.0.6",
-    "@smithy/signature-v4": "^2.0.10",
-    "@smithy/types": "^2.3.4",
-    "axios": "^1.3.5",
+    "@aws-crypto/sha256-js": "^5.2.0",
+    "@huggingface/jinja": "^0.3.0",
+    "@node-rs/argon2": "^1.8.3",
+    "@smithy/eventstream-codec": "^2.1.3",
+    "@smithy/eventstream-serde-node": "^2.1.3",
+    "@smithy/protocol-http": "^3.2.1",
+    "@smithy/signature-v4": "^2.1.3",
+    "@smithy/util-utf8": "^2.1.1",
+    "axios": "^1.7.4",
+    "better-sqlite3": "^10.0.0",
     "check-disk-space": "^3.4.0",
     "cookie-parser": "^1.4.6",
     "copyfiles": "^2.4.1",
     "cors": "^2.8.5",
     "csrf-csrf": "^2.3.0",
-    "dotenv": "^16.0.3",
-    "ejs": "^3.1.9",
-    "express": "^4.18.2",
+    "dotenv": "^16.3.1",
+    "ejs": "^3.1.10",
+    "express": "^4.19.3",
     "express-session": "^1.17.3",
-    "firebase-admin": "^11.10.1",
+    "firebase-admin": "^12.5.0",
+    "glob": "^10.3.12",
     "googleapis": "^122.0.0",
-    "http-proxy-middleware": "^3.0.0-beta.1",
-    "lifion-aws-event-stream": "^1.0.7",
+    "http-proxy": "1.18.1",
+    "http-proxy-middleware": "^3.0.2",
+    "ipaddr.js": "^2.1.0",
     "memorystore": "^1.6.7",
     "multer": "^1.4.5-lts.1",
     "node-schedule": "^2.1.1",
+    "patch-package": "^8.0.0",
     "pino": "^8.11.0",
     "pino-http": "^8.3.3",
-    "sanitize-html": "^2.11.0",
+    "proxy-agent": "^6.4.0",
+    "sanitize-html": "^2.13.0",
     "sharp": "^0.32.6",
     "showdown": "^2.1.0",
+    "source-map-support": "^0.5.21",
     "stream-json": "^1.8.0",
     "tiktoken": "^1.0.10",
+    "tinyws": "^0.1.0",
     "uuid": "^9.0.0",
     "zlib": "^1.0.5",
     "zod": "^3.22.3",
     "zod-error": "^1.5.0"
   },
   "devDependencies": {
+    "@smithy/types": "^3.3.0",
+    "@types/better-sqlite3": "^7.6.10",
     "@types/cookie-parser": "^1.4.3",
     "@types/cors": "^2.8.13",
     "@types/express": "^4.17.17",
@@ -69,12 +84,13 @@
     "nodemon": "^3.0.1",
     "pino-pretty": "^10.2.3",
     "prettier": "^3.0.3",
-    "source-map-support": "^0.5.21",
+    "prettier-plugin-ejs": "^1.0.3",
     "ts-node": "^10.9.1",
-    "typescript": "^5.1.3"
+    "typescript": "^5.4.2"
   },
   "overrides": {
-    "google-gax": "^3.6.1",
-    "postcss": "^8.4.31"
+    "node-fetch@2.x": {
+      "whatwg-url": "14.x"
+    }
   }
 }

patches/README.md

@@ -0,0 +1,23 @@
+# Patches
+Contains monkey patches for certain packages, applied using `patch-package`.
+
+## `http-proxy+1.18.1.patch`
+Modifies the `http-proxy` package to work around an incompatibility with
+body-parser and SOCKS5 proxies due to some esoteric stream handling behavior
+when `socks-proxy-agent` is used instead of a generic http.Agent.
+
+Modification involves adjusting the `buffer` property on ProxyServer's `options`
+object to be a function that returns a stream instead of a stream itself. This
+allows us to give it a function which produces a new Readable from the already-
+parsed request body.
+
+With the old implementation we would need to create an entirely new ProxyServer
+instance for each request, which is not ideal under heavy load.
+
+`http-proxy` hasn't been updated in six years so it's unlikely that this patch
+will be broken by future updates, but it's stil pinned to 1.18.1 for now.
+
+### See also
+https://github.com/chimurai/http-proxy-middleware/issues/40
+https://github.com/chimurai/http-proxy-middleware/issues/299
+https://github.com/http-party/node-http-proxy/pull/1027

patches/http-proxy+1.18.1.patch

@@ -0,0 +1,13 @@
+diff --git a/node_modules/http-proxy/lib/http-proxy/passes/web-incoming.js b/node_modules/http-proxy/lib/http-proxy/passes/web-incoming.js
+index 7ae7355..c825c27 100644
+--- a/node_modules/http-proxy/lib/http-proxy/passes/web-incoming.js
++++ b/node_modules/http-proxy/lib/http-proxy/passes/web-incoming.js
+@@ -167,7 +167,7 @@ module.exports = {
+       }
+     }
+ 
+-    (options.buffer || req).pipe(proxyReq);
++    (options.buffer(req) || req).pipe(proxyReq);
+ 
+     proxyReq.on('response', function(proxyRes) {
+       if(server) { server.emit('proxyRes', proxyRes, req, res); }

public/css/reset.css

@@ -0,0 +1,349 @@
+/*! normalize.css v8.0.1 | MIT License | github.com/necolas/normalize.css */
+
+/* Document
+   ========================================================================== */
+
+/**
+ * 1. Correct the line height in all browsers.
+ * 2. Prevent adjustments of font size after orientation changes in iOS.
+ */
+
+html {
+    line-height: 1.15; /* 1 */
+    -webkit-text-size-adjust: 100%; /* 2 */
+}
+
+/* Sections
+   ========================================================================== */
+
+/**
+ * Remove the margin in all browsers.
+ */
+
+body {
+    margin: 0;
+}
+
+/**
+ * Render the `main` element consistently in IE.
+ */
+
+main {
+    display: block;
+}
+
+/**
+ * Correct the font size and margin on `h1` elements within `section` and
+ * `article` contexts in Chrome, Firefox, and Safari.
+ */
+
+h1 {
+    font-size: 2em;
+    margin: 0.67em 0;
+}
+
+/* Grouping content
+   ========================================================================== */
+
+/**
+ * 1. Add the correct box sizing in Firefox.
+ * 2. Show the overflow in Edge and IE.
+ */
+
+hr {
+    box-sizing: content-box; /* 1 */
+    height: 0; /* 1 */
+    overflow: visible; /* 2 */
+}
+
+/**
+ * 1. Correct the inheritance and scaling of font size in all browsers.
+ * 2. Correct the odd `em` font sizing in all browsers.
+ */
+
+pre {
+    font-family: monospace, monospace; /* 1 */
+    font-size: 1em; /* 2 */
+}
+
+/* Text-level semantics
+   ========================================================================== */
+
+/**
+ * Remove the gray background on active links in IE 10.
+ */
+
+a {
+    background-color: transparent;
+}
+
+/**
+ * 1. Remove the bottom border in Chrome 57-
+ * 2. Add the correct text decoration in Chrome, Edge, IE, Opera, and Safari.
+ */
+
+abbr[title] {
+    border-bottom: none; /* 1 */
+    text-decoration: underline; /* 2 */
+    text-decoration: underline dotted; /* 2 */
+}
+
+/**
+ * Add the correct font weight in Chrome, Edge, and Safari.
+ */
+
+b,
+strong {
+    font-weight: bolder;
+}
+
+/**
+ * 1. Correct the inheritance and scaling of font size in all browsers.
+ * 2. Correct the odd `em` font sizing in all browsers.
+ */
+
+code,
+kbd,
+samp {
+    font-family: monospace, monospace; /* 1 */
+    font-size: 1em; /* 2 */
+}
+
+/**
+ * Add the correct font size in all browsers.
+ */
+
+small {
+    font-size: 80%;
+}
+
+/**
+ * Prevent `sub` and `sup` elements from affecting the line height in
+ * all browsers.
+ */
+
+sub,
+sup {
+    font-size: 75%;
+    line-height: 0;
+    position: relative;
+    vertical-align: baseline;
+}
+
+sub {
+    bottom: -0.25em;
+}
+
+sup {
+    top: -0.5em;
+}
+
+/* Embedded content
+   ========================================================================== */
+
+/**
+ * Remove the border on images inside links in IE 10.
+ */
+
+img {
+    border-style: none;
+}
+
+/* Forms
+   ========================================================================== */
+
+/**
+ * 1. Change the font styles in all browsers.
+ * 2. Remove the margin in Firefox and Safari.
+ */
+
+button,
+input,
+optgroup,
+select,
+textarea {
+    font-family: inherit; /* 1 */
+    font-size: 100%; /* 1 */
+    line-height: 1.15; /* 1 */
+    margin: 0; /* 2 */
+}
+
+/**
+ * Show the overflow in IE.
+ * 1. Show the overflow in Edge.
+ */
+
+button,
+input { /* 1 */
+    overflow: visible;
+}
+
+/**
+ * Remove the inheritance of text transform in Edge, Firefox, and IE.
+ * 1. Remove the inheritance of text transform in Firefox.
+ */
+
+button,
+select { /* 1 */
+    text-transform: none;
+}
+
+/**
+ * Correct the inability to style clickable types in iOS and Safari.
+ */
+
+button,
+[type="button"],
+[type="reset"],
+[type="submit"] {
+    -webkit-appearance: button;
+}
+
+/**
+ * Remove the inner border and padding in Firefox.
+ */
+
+button::-moz-focus-inner,
+[type="button"]::-moz-focus-inner,
+[type="reset"]::-moz-focus-inner,
+[type="submit"]::-moz-focus-inner {
+    border-style: none;
+    padding: 0;
+}
+
+/**
+ * Restore the focus styles unset by the previous rule.
+ */
+
+button:-moz-focusring,
+[type="button"]:-moz-focusring,
+[type="reset"]:-moz-focusring,
+[type="submit"]:-moz-focusring {
+    outline: 1px dotted ButtonText;
+}
+
+/**
+ * Correct the padding in Firefox.
+ */
+
+fieldset {
+    padding: 0.35em 0.75em 0.625em;
+}
+
+/**
+ * 1. Correct the text wrapping in Edge and IE.
+ * 2. Correct the color inheritance from `fieldset` elements in IE.
+ * 3. Remove the padding so developers are not caught out when they zero out
+ *    `fieldset` elements in all browsers.
+ */
+
+legend {
+    box-sizing: border-box; /* 1 */
+    color: inherit; /* 2 */
+    display: table; /* 1 */
+    max-width: 100%; /* 1 */
+    padding: 0; /* 3 */
+    white-space: normal; /* 1 */
+}
+
+/**
+ * Add the correct vertical alignment in Chrome, Firefox, and Opera.
+ */
+
+progress {
+    vertical-align: baseline;
+}
+
+/**
+ * Remove the default vertical scrollbar in IE 10+.
+ */
+
+textarea {
+    overflow: auto;
+}
+
+/**
+ * 1. Add the correct box sizing in IE 10.
+ * 2. Remove the padding in IE 10.
+ */
+
+[type="checkbox"],
+[type="radio"] {
+    box-sizing: border-box; /* 1 */
+    padding: 0; /* 2 */
+}
+
+/**
+ * Correct the cursor style of increment and decrement buttons in Chrome.
+ */
+
+[type="number"]::-webkit-inner-spin-button,
+[type="number"]::-webkit-outer-spin-button {
+    height: auto;
+}
+
+/**
+ * 1. Correct the odd appearance in Chrome and Safari.
+ * 2. Correct the outline style in Safari.
+ */
+
+[type="search"] {
+    -webkit-appearance: textfield; /* 1 */
+    outline-offset: -2px; /* 2 */
+}
+
+/**
+ * Remove the inner padding in Chrome and Safari on macOS.
+ */
+
+[type="search"]::-webkit-search-decoration {
+    -webkit-appearance: none;
+}
+
+/**
+ * 1. Correct the inability to style clickable types in iOS and Safari.
+ * 2. Change font properties to `inherit` in Safari.
+ */
+
+::-webkit-file-upload-button {
+    -webkit-appearance: button; /* 1 */
+    font: inherit; /* 2 */
+}
+
+/* Interactive
+   ========================================================================== */
+
+/*
+ * Add the correct display in Edge, IE 10+, and Firefox.
+ */
+
+details {
+    display: block;
+}
+
+/*
+ * Add the correct display in all browsers.
+ */
+
+summary {
+    display: list-item;
+}
+
+/* Misc
+   ========================================================================== */
+
+/**
+ * Add the correct display in IE 10+.
+ */
+
+template {
+    display: none;
+}
+
+/**
+ * Add the correct display in IE 10.
+ */
+
+[hidden] {
+    display: none;
+}

public/css/sakura-dark.css

@@ -0,0 +1,231 @@
+/* modified https://github.com/oxalorg/sakura */
+html {
+  font-size: 62.5%;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
+    "Helvetica Neue", Arial, "Noto Sans", sans-serif;
+}
+body {
+  font-size: 1.8rem;
+  line-height: 1.618;
+  max-width: 38em;
+  margin: auto;
+  color: #c9c9c9;
+  background-color: #222222;
+  padding: 13px;
+}
+@media (max-width: 684px) {
+  body {
+    font-size: 1.53rem;
+  }
+}
+@media (max-width: 382px) {
+  body {
+    font-size: 1.35rem;
+  }
+}
+h1,
+h2,
+h3,
+h4,
+h5,
+h6 {
+  line-height: 1.1;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
+    "Helvetica Neue", Arial, "Noto Sans", sans-serif;
+  font-weight: 700;
+  margin-top: 3rem;
+  margin-bottom: 1.5rem;
+  overflow-wrap: break-word;
+  word-wrap: break-word;
+  -ms-word-break: break-all;
+  word-break: break-word;
+}
+h1 {
+  font-size: 2.35em;
+}
+h2 {
+  font-size: 2em;
+}
+h3 {
+  font-size: 1.75em;
+}
+h4 {
+  font-size: 1.5em;
+}
+h5 {
+  font-size: 1.25em;
+}
+h6 {
+  font-size: 1em;
+}
+p {
+  margin-top: 0px;
+  margin-bottom: 2.5rem;
+}
+small,
+sub,
+sup {
+  font-size: 75%;
+}
+hr {
+  border-color: #ffffff;
+}
+a {
+  text-decoration: none;
+  color: #ffffff;
+}
+a:visited {
+  color: #e6e6e6;
+}
+a:hover {
+  color: #c9c9c9;
+  text-decoration: underline;
+}
+ul {
+  padding-left: 1.4em;
+  margin-top: 0px;
+  margin-bottom: 2.5rem;
+}
+li {
+  margin-bottom: 0.4em;
+}
+blockquote {
+  margin-left: 0px;
+  margin-right: 0px;
+  padding-left: 1em;
+  padding-top: 0.8em;
+  padding-bottom: 0.8em;
+  padding-right: 0.8em;
+  border-left: 5px solid #ffffff;
+  margin-bottom: 2.5rem;
+  background-color: #4a4a4a;
+}
+blockquote p {
+  margin-bottom: 0;
+}
+img,
+video {
+  height: auto;
+  max-width: 100%;
+  margin-top: 0px;
+  margin-bottom: 2.5rem;
+}
+pre {
+  background-color: #4a4a4a;
+  display: block;
+  padding: 1em;
+  overflow-x: auto;
+  margin-top: 0px;
+  margin-bottom: 2.5rem;
+  font-size: 0.9em;
+}
+code,
+kbd,
+samp {
+  font-size: 0.9em;
+  padding: 0 0.5em;
+  background-color: #4a4a4a;
+  white-space: pre-wrap;
+}
+pre > code {
+  padding: 0;
+  background-color: transparent;
+  white-space: pre;
+  font-size: 1em;
+}
+table {
+  text-align: justify;
+  width: 100%;
+  border-collapse: collapse;
+  margin-bottom: 2rem;
+}
+td,
+th {
+  padding: 0.5em;
+  border-bottom: 1px solid #4a4a4a;
+}
+input,
+textarea {
+  border: 1px solid #c9c9c9;
+}
+input:focus,
+textarea:focus {
+  border: 1px solid #ffffff;
+}
+textarea {
+  width: 100%;
+}
+.button,
+button,
+input[type="submit"],
+input[type="reset"],
+input[type="button"],
+input[type="file"]::file-selector-button {
+  display: inline-block;
+  padding: 5px 10px;
+  text-align: center;
+  text-decoration: none;
+  white-space: nowrap;
+  background-color: #ffffff;
+  color: #222222;
+  border-radius: 1px;
+  border: 1px solid #ffffff;
+  cursor: pointer;
+  box-sizing: border-box;
+}
+.button[disabled],
+button[disabled],
+input[type="submit"][disabled],
+input[type="reset"][disabled],
+input[type="button"][disabled],
+input[type="file"][disabled] {
+  cursor: default;
+  opacity: 0.5;
+}
+.button:hover,
+button:hover,
+input[type="submit"]:hover,
+input[type="reset"]:hover,
+input[type="button"]:hover,
+input[type="file"]::file-selector-button:hover {
+  background-color: #c9c9c9;
+  color: #222222;
+  outline: 0;
+}
+.button:focus-visible,
+button:focus-visible,
+input[type="submit"]:focus-visible,
+input[type="reset"]:focus-visible,
+input[type="button"]:focus-visible,
+input[type="file"]::file-selector-button:focus-visible {
+  outline-style: solid;
+  outline-width: 2px;
+}
+textarea,
+select,
+input {
+  color: #c9c9c9;
+  padding: 6px 10px;
+  margin-bottom: 10px;
+  background-color: #4a4a4a;
+  border: 1px solid #4a4a4a;
+  border-radius: 4px;
+  box-shadow: none;
+  box-sizing: border-box;
+}
+textarea:focus,
+select:focus,
+input:focus {
+  border: 1px solid #ffffff;
+  outline: 0;
+}
+input[type="checkbox"]:focus {
+  outline: 1px dotted #ffffff;
+}
+label,
+legend,
+fieldset {
+  display: block;
+  margin-bottom: 0.5rem;
+  font-weight: 600;
+}

public/css/sakura.css

@@ -0,0 +1,237 @@
+/* modified https://github.com/oxalorg/sakura */
+:root {
+  --accent-color: #4a4a4a;
+  --accent-color-hover: #5a5a5a;
+  --link-color: #58739c;
+  --link-visted-color: #6f5e6f;
+}
+html {
+  font-size: 62.5%;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
+    "Helvetica Neue", Arial, "Noto Sans", sans-serif;
+}
+body {
+  font-size: 1.8rem;
+  line-height: 1.618;
+  max-width: 38em;
+  margin: auto;
+  color: #4a4a4a;
+  background-color: #f9f9f9;
+  padding: 13px;
+}
+@media (max-width: 684px) {
+  body {
+    font-size: 1.53rem;
+  }
+}
+@media (max-width: 382px) {
+  body {
+    font-size: 1.35rem;
+  }
+}
+h1,
+h2,
+h3,
+h4,
+h5,
+h6 {
+  line-height: 1.1;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
+    "Helvetica Neue", Arial, "Noto Sans", sans-serif;
+  font-weight: 700;
+  margin-top: 3rem;
+  margin-bottom: 1.5rem;
+  overflow-wrap: break-word;
+  word-wrap: break-word;
+  -ms-word-break: break-all;
+  word-break: break-word;
+}
+h1 {
+  font-size: 2.35em;
+}
+h2 {
+  font-size: 2em;
+}
+h3 {
+  font-size: 1.75em;
+}
+h4 {
+  font-size: 1.5em;
+}
+h5 {
+  font-size: 1.25em;
+}
+h6 {
+  font-size: 1em;
+}
+p {
+  margin-top: 0;
+  margin-bottom: 2.5rem;
+}
+small,
+sub,
+sup {
+  font-size: 75%;
+}
+hr {
+  border-color: var(--accent-color);
+}
+a {
+  text-decoration: none;
+  color: var(--link-color);
+}
+a:visited {
+  color: var(--link-visted-color);
+}
+a:hover {
+  color: var(--accent-color-hover);
+  text-decoration: underline;
+}
+ul {
+  padding-left: 1.4em;
+  margin-top: 0;
+  margin-bottom: 2.5rem;
+}
+li {
+  margin-bottom: 0.4em;
+}
+blockquote {
+  margin-left: 0;
+  margin-right: 0;
+  padding-left: 1em;
+  padding-top: 0.8em;
+  padding-bottom: 0.8em;
+  padding-right: 0.8em;
+  border-left: 5px solid var(--accent-color);
+  margin-bottom: 2.5rem;
+  background-color: #f1f1f1;
+}
+blockquote p {
+  margin-bottom: 0;
+}
+img,
+video {
+  height: auto;
+  max-width: 100%;
+  margin-top: 0;
+  margin-bottom: 2.5rem;
+}
+pre {
+  background-color: #f1f1f1;
+  display: block;
+  padding: 1em;
+  overflow-x: auto;
+  margin-top: 0;
+  margin-bottom: 2.5rem;
+  font-size: 0.9em;
+}
+code,
+kbd,
+samp {
+  font-size: 0.9em;
+  padding: 0 0.5em;
+  background-color: #f1f1f1;
+  white-space: pre-wrap;
+}
+pre > code {
+  padding: 0;
+  background-color: transparent;
+  white-space: pre;
+  font-size: 1em;
+}
+table {
+  text-align: justify;
+  width: 100%;
+  border-collapse: collapse;
+  margin-bottom: 2rem;
+}
+td,
+th {
+  padding: 0.5em;
+  border-bottom: 1px solid #f1f1f1;
+}
+input,
+textarea {
+  border: 1px solid #4a4a4a;
+}
+input:focus,
+textarea:focus {
+  border: 1px solid var(--accent-color);
+}
+textarea {
+  width: 100%;
+}
+.button,
+button,
+input[type="submit"],
+input[type="reset"],
+input[type="button"],
+input[type="file"]::file-selector-button {
+  display: inline-block;
+  padding: 5px 10px;
+  text-align: center;
+  text-decoration: none;
+  white-space: nowrap;
+  background-color: var(--accent-color);
+  color: #f9f9f9;
+  border-radius: 2px;
+  border: 1px solid var(--accent-color);
+  cursor: pointer;
+  box-sizing: border-box;
+}
+.button[disabled],
+button[disabled],
+input[type="submit"][disabled],
+input[type="reset"][disabled],
+input[type="button"][disabled],
+input[type="file"][disabled] {
+  cursor: default;
+  opacity: 0.5;
+}
+.button:hover,
+button:hover,
+input[type="submit"]:hover,
+input[type="reset"]:hover,
+input[type="button"]:hover,
+input[type="file"]::file-selector-button:hover {
+  background-color: var(--accent-color-hover);
+  color: #f9f9f9;
+  outline: 0;
+}
+.button:focus-visible,
+button:focus-visible,
+input[type="submit"]:focus-visible,
+input[type="reset"]:focus-visible,
+input[type="button"]:focus-visible,
+input[type="file"]::file-selector-button:focus-visible {
+  outline-style: solid;
+  outline-width: 2px;
+}
+textarea,
+select,
+input {
+  color: #4a4a4a;
+  padding: 6px 10px;
+  margin-bottom: 10px;
+  background-color: #f1f1f1;
+  border: 1px solid #f1f1f1;
+  border-radius: 4px;
+  box-shadow: none;
+  box-sizing: border-box;
+}
+textarea:focus,
+select:focus,
+input:focus {
+  border: 1px solid var(--accent-color);
+  outline: 0;
+}
+input[type="checkbox"]:focus {
+  outline: 1px dotted var(--accent-color);
+}
+label,
+legend,
+fieldset {
+  display: block;
+  margin-bottom: 0.5rem;
+  font-weight: 600;
+}

public/js/hash-worker.js

@@ -0,0 +1,120 @@
+importScripts(
+  "https://cdn.jsdelivr.net/npm/hash-wasm@4.11.0/dist/argon2.umd.min.js"
+);
+
+let active = false;
+let nonce = 0;
+let signature = "";
+let lastNotify = 0;
+let hashesSinceLastNotify = 0;
+let params = {
+  salt: null,
+  hashLength: 0,
+  iterations: 0,
+  memorySize: 0,
+  parallelism: 0,
+  targetValue: BigInt(0),
+  safariFix: false,
+};
+
+self.onmessage = async (event) => {
+  const { data } = event;
+  switch (data.type) {
+    case "stop":
+      active = false;
+      self.postMessage({ type: "paused", hashes: hashesSinceLastNotify });
+      return;
+    case "start":
+      active = true;
+      signature = data.signature;
+      nonce = data.nonce;
+
+      const c = data.challenge;
+      const salt = new Uint8Array(c.s.length / 2);
+      for (let i = 0; i < c.s.length; i += 2) {
+        salt[i / 2] = parseInt(c.s.slice(i, i + 2), 16);
+      }
+
+      params = {
+        salt: salt,
+        hashLength: c.hl,
+        iterations: c.t,
+        memorySize: c.m,
+        parallelism: c.p,
+        targetValue: BigInt(c.d.slice(0, -1)),
+        safariFix: data.isMobileWebkit,
+      };
+
+      console.log("Started", params);
+      self.postMessage({ type: "started" });
+      setTimeout(solve, 0);
+      break;
+  }
+};
+
+const doHash = async (password) => {
+  const { salt, hashLength, iterations, memorySize, parallelism } = params;
+  return await self.hashwasm.argon2id({
+    password,
+    salt,
+    hashLength,
+    iterations,
+    memorySize,
+    parallelism,
+  });
+};
+
+const checkHash = (hash) => {
+  const { targetValue } = params;
+  const hashValue = BigInt(`0x${hash}`);
+  return hashValue <= targetValue;
+};
+
+const solve = async () => {
+  if (!active) {
+    console.log("Stopped solver", nonce);
+    return;
+  }
+
+  // Safari WASM doesn't like multiple calls in one worker
+  const batchSize = 1;
+  const batch = [];
+  for (let i = 0; i < batchSize; i++) {
+    batch.push(nonce++);
+  }
+
+  try {
+    const results = await Promise.all(
+      batch.map(async (nonce) => {
+        const hash = await doHash(String(nonce));
+        return { hash, nonce };
+      })
+    );
+    hashesSinceLastNotify += batchSize;
+
+    const solution = results.find(({ hash }) => checkHash(hash));
+    if (solution) {
+      console.log("Solution found", solution, params.salt);
+      self.postMessage({ type: "solved", nonce: solution.nonce });
+      active = false;
+    } else {
+      if (Date.now() - lastNotify >= 500) {
+        console.log("Last nonce", nonce, "Hashes", hashesSinceLastNotify);
+        self.postMessage({ type: "progress", hashes: hashesSinceLastNotify });
+        lastNotify = Date.now();
+        hashesSinceLastNotify = 0;
+      }
+      setTimeout(solve, 10);
+    }
+  } catch (error) {
+    console.error("Error", error);
+    const stack = error.stack;
+    const debug = {
+      stack,
+      lastNonce: nonce,
+      targetValue: params.targetValue,
+    };
+    self.postMessage({ type: "error", error: error.message, debug });
+    active = false;
+  }
+};

scripts/migrate.ts

@@ -0,0 +1,39 @@
+import Database from "better-sqlite3";
+import { DATABASE_VERSION, migrateDatabase } from "../src/shared/database";
+import { logger } from "../src/logger";
+import { config } from "../src/config";
+
+const log = logger.child({ module: "scripts/migrate" });
+
+async function runMigration() {
+  let targetVersion = Number(process.argv[2]) || undefined;
+
+  if (!targetVersion) {
+    log.info("Enter target version or leave empty to use the latest version.");
+    process.stdin.resume();
+    process.stdin.setEncoding("utf8");
+    const input = await new Promise<string>((resolve) => {
+      process.stdin.on("data", (text) => {
+        resolve((String(text) || "").trim());
+      });
+    });
+    process.stdin.pause();
+    targetVersion = Number(input);
+    if (!targetVersion) {
+      targetVersion = DATABASE_VERSION;
+    }
+  }
+
+  const db = new Database(config.sqliteDataPath, {
+    verbose: (msg, ...args) => log.debug({ args }, String(msg)),
+  });
+
+  const currentVersion = db.pragma("user_version", { simple: true });
+  log.info({ currentVersion, targetVersion }, "Running migrations.");
+  migrateDatabase(targetVersion, db);
+}
+
+runMigration().catch((error) => {
+  log.error(error, "Migration failed.");
+  process.exit(1);
+});

scripts/oai-reverse-proxy.http

@@ -230,6 +230,39 @@ Content-Type: application/json
   ]
 }
 
+###
+# @name Proxy / GCP Claude -- Native Completion
+POST {{proxy-host}}/proxy/gcp/claude/v1/complete
+Authorization: Bearer {{proxy-key}}
+anthropic-version: 2023-01-01
+Content-Type: application/json
+
+{
+  "model": "claude-v2",
+  "max_tokens_to_sample": 10,
+  "temperature": 0,
+  "stream": true,
+  "prompt": "What is genshin impact\n\n:Assistant:"
+}
+
+###
+# @name Proxy / GCP Claude -- OpenAI-to-Anthropic API Translation
+POST {{proxy-host}}/proxy/gcp/claude/chat/completions
+Authorization: Bearer {{proxy-key}}
+Content-Type: application/json
+
+{
+  "model": "gpt-3.5-turbo",
+  "max_tokens": 50,
+  "stream": true,
+  "messages": [
+    {
+      "role": "user",
+      "content": "What is genshin impact?"
+    }
+  ]
+}
+
 ###
 # @name Proxy / Azure OpenAI -- Native Chat Completions
 POST {{proxy-host}}/proxy/azure/openai/chat/completions

scripts/seed-events.ts

@@ -0,0 +1,102 @@
+import Database from "better-sqlite3";
+import { v4 as uuidv4 } from "uuid";
+import { config } from "../src/config";
+
+function generateRandomIP() {
+  return (
+    Math.floor(Math.random() * 255) +
+    "." +
+    Math.floor(Math.random() * 255) +
+    "." +
+    Math.floor(Math.random() * 255) +
+    "." +
+    Math.floor(Math.random() * 255)
+  );
+}
+
+function generateRandomDate() {
+  const end = new Date();
+  const start = new Date(end);
+  start.setDate(end.getDate() - 90);
+  const randomDate = new Date(
+    start.getTime() + Math.random() * (end.getTime() - start.getTime())
+  );
+  return randomDate.toISOString();
+}
+
+function generateMockSHA256() {
+  const characters = 'abcdef0123456789';
+  let hash = '';
+
+  for (let i = 0; i < 64; i++) {
+    const randomIndex = Math.floor(Math.random() * characters.length);
+    hash += characters[randomIndex];
+  }
+
+  return hash;
+}
+
+function getRandomModelFamily() {
+  const modelFamilies = [
+    "turbo",
+    "gpt4",
+    "gpt4-32k",
+    "gpt4-turbo",
+    "claude",
+    "claude-opus",
+    "gemini-pro",
+    "mistral-tiny",
+    "mistral-small",
+    "mistral-medium",
+    "mistral-large",
+    "aws-claude",
+    "aws-claude-opus",
+    "gcp-claude",
+    "gcp-claude-opus",
+    "azure-turbo",
+    "azure-gpt4",
+    "azure-gpt4-32k",
+    "azure-gpt4-turbo",
+    "dall-e",
+    "azure-dall-e",
+  ];
+  return modelFamilies[Math.floor(Math.random() * modelFamilies.length)];
+}
+
+(async () => {
+  const db = new Database(config.sqliteDataPath);
+  const numRows = 100;
+  const insertStatement = db.prepare(`
+  INSERT INTO events (type, ip, date, model, family, hashes, userToken, inputTokens, outputTokens)
+  VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+`);
+
+  const users = Array.from({ length: 10 }, () => uuidv4());
+  function getRandomUser() {
+    return users[Math.floor(Math.random() * users.length)];
+  }
+
+  const transaction = db.transaction(() => {
+    for (let i = 0; i < numRows; i++) {
+      insertStatement.run(
+        "chat_completion",
+        generateRandomIP(),
+        generateRandomDate(),
+        getRandomModelFamily() + "-" + Math.floor(Math.random() * 100),
+        getRandomModelFamily(),
+        Array.from(
+          { length: Math.floor(Math.random() * 10) },
+          generateMockSHA256
+        ).join(","),
+        getRandomUser(),
+        Math.floor(Math.random() * 500),
+        Math.floor(Math.random() * 6000)
+      );
+    }
+  });
+
+  transaction();
+
+  console.log(`Inserted ${numRows} rows into the events table.`);
+  db.close();
+})();

scripts/test-aws-signing.ts

@@ -0,0 +1,118 @@
+// uses the aws sdk to sign a request, then uses axios to send it to the bedrock REST API manually
+import axios from "axios";
+import { Sha256 } from "@aws-crypto/sha256-js";
+import { SignatureV4 } from "@smithy/signature-v4";
+import { HttpRequest } from "@smithy/protocol-http";
+
+const AWS_ACCESS_KEY_ID = process.env.AWS_ACCESS_KEY_ID!;
+const AWS_SECRET_ACCESS_KEY = process.env.AWS_SECRET_ACCESS_KEY!;
+
+// Copied from amazon bedrock docs
+
+// List models
+// ListFoundationModels
+// Service: Amazon Bedrock
+// List of Bedrock foundation models that you can use. For more information, see Foundation models in the
+// Bedrock User Guide.
+//   Request Syntax
+// GET /foundation-models?
+//   byCustomizationType=byCustomizationType&byInferenceType=byInferenceType&byOutputModality=byOutputModality&byProvider=byProvider
+//   HTTP/1.1
+// URI Request Parameters
+// The request uses the following URI parameters.
+// byCustomizationType (p. 38)
+// List by customization type.
+//   Valid Values: FINE_TUNING
+// byInferenceType (p. 38)
+// List by inference type.
+//   Valid Values: ON_DEMAND | PROVISIONED
+// byOutputModality (p. 38)
+// List by output modality type.
+//   Valid Values: TEXT | IMAGE | EMBEDDING
+// byProvider (p. 38)
+// A Bedrock model provider.
+//   Pattern: ^[a-z0-9-]{1,63}$
+// Request Body
+// The request does not have a request body
+
+// Run inference on a text model
+// Send an invoke request to run inference on a Titan Text G1 - Express model. We set the accept
+// parameter to accept any content type in the response.
+//   POST https://bedrock.us-east-1.amazonaws.com/model/amazon.titan-text-express-v1/invoke
+//   -H accept: */*
+// -H content-type: application/json
+// Payload
+// {"inputText": "Hello world"}
+// Example response
+// Response for the above request.
+// -H content-type: application/json
+// Payload
+// <the model response>
+
+const AMZ_REGION = "us-east-1";
+const AMZ_HOST = "invoke-bedrock.us-east-1.amazonaws.com";
+
+async function listModels() {
+  const httpRequest = new HttpRequest({
+    method: "GET",
+    protocol: "https:",
+    hostname: AMZ_HOST,
+    path: "/foundation-models",
+    headers: { ["Host"]: AMZ_HOST },
+  });
+
+  const signedRequest = await signRequest(httpRequest);
+  const response = await axios.get(
+    `https://${signedRequest.hostname}${signedRequest.path}`,
+    { headers: signedRequest.headers }
+  );
+  console.log(response.data);
+}
+
+async function invokeModel() {
+  const model = "anthropic.claude-v1";
+  const httpRequest = new HttpRequest({
+    method: "POST",
+    protocol: "https:",
+    hostname: AMZ_HOST,
+    path: `/model/${model}/invoke`,
+    headers: {
+      ["Host"]: AMZ_HOST,
+      ["accept"]: "*/*",
+      ["content-type"]: "application/json",
+    },
+    body: JSON.stringify({
+      temperature: 0.5,
+      prompt: "\n\nHuman:Hello world\n\nAssistant:",
+      max_tokens_to_sample: 10,
+    }),
+  });
+  console.log("httpRequest", httpRequest);
+
+  const signedRequest = await signRequest(httpRequest);
+  const response = await axios.post(
+    `https://${signedRequest.hostname}${signedRequest.path}`,
+    signedRequest.body,
+    { headers: signedRequest.headers }
+  );
+  console.log(response.status);
+  console.log(response.headers);
+  console.log(response.data);
+  console.log("full url", response.request.res.responseUrl);
+}
+
+async function signRequest(request: HttpRequest) {
+  const signer = new SignatureV4({
+    sha256: Sha256,
+    credentials: {
+      accessKeyId: AWS_ACCESS_KEY_ID,
+      secretAccessKey: AWS_SECRET_ACCESS_KEY,
+    },
+    region: AMZ_REGION,
+    service: "bedrock",
+  });
+  return await signer.sign(request, { signingDate: new Date() });
+}
+
+// listModels();
+// invokeModel();

scripts/test-queue.js

@@ -0,0 +1,53 @@
+const axios = require("axios");
+
+function randomInteger(max) {
+  return Math.floor(Math.random() * max + 1);
+}
+
+async function testQueue() {
+  const requests = Array(10).fill(undefined).map(async function() {
+    const maxTokens = randomInteger(2000);
+
+    const headers = {
+      "Authorization": "Bearer test",
+      "Content-Type": "application/json",
+      "X-Forwarded-For": `${randomInteger(255)}.${randomInteger(255)}.${randomInteger(255)}.${randomInteger(255)}`,
+    };
+
+    const payload = {
+      model: "gpt-4o-mini-2024-07-18",
+      max_tokens: 20 + maxTokens,
+      stream: false,
+      messages: [{role: "user", content: "You are being benchmarked regarding your reliability at outputting exact, machine-comprehensible data. Output the sentence \"The quick brown fox jumps over the lazy dog.\" Do not precede it with quotemarks or any form of preamble, and do not output anything after the sentence."}],
+      temperature: 0,
+    };
+
+    try {
+      const response = await axios.post(
+        "http://localhost:7860/proxy/openai/v1/chat/completions",
+        payload,
+        { headers }
+      );
+
+            if (response.status !== 200) {
+          console.error(`Request {$maxTokens} finished with status code ${response.status} and response`, response.data);
+          return;
+        }
+
+      const content = response.data.choices[0].message.content;
+
+      console.log(
+        `Request ${maxTokens} `,
+        content === "The quick brown fox jumps over the lazy dog." ? "OK" : `mangled: ${content}`
+      );
+    } catch (error) {
+      const msg = error.response;
+      console.error(`Error in req ${maxTokens}:`, error.message, msg || "");
+    }
+  });
+
+  await Promise.all(requests);
+  console.log("All requests finished");
+}
+
+testQueue();

src/admin/api/events.ts

@@ -0,0 +1,49 @@
+import { Router } from "express";
+import { z } from "zod";
+import { encodeCursor, decodeCursor } from "../../shared/utils";
+import { eventsRepo } from "../../shared/database/repos/event";
+
+const router = Router();
+
+/**
+ * Returns events for the given user token.
+ * GET /admin/events/:token
+ * @query first - The number of events to return.
+ * @query after - The cursor to start returning events from (exclusive).
+ */
+router.get("/:token", (req, res) => {
+  const schema = z.object({
+    token: z.string(),
+    first: z.coerce.number().int().positive().max(200).default(25),
+    after: z
+      .string()
+      .optional()
+      .transform((v) => {
+        try {
+          return decodeCursor(v);
+        } catch {
+          return null;
+        }
+      })
+      .nullable(),
+    sort: z.string().optional(),
+  });
+  const args = schema.safeParse({ ...req.params, ...req.query });
+  if (!args.success) {
+    return res.status(400).json({ error: args.error });
+  }
+
+  const data = eventsRepo
+    .getUserEvents(args.data.token, {
+      limit: args.data.first,
+      cursor: args.data.after,
+    })
+    .map((e) => ({ node: e, cursor: encodeCursor(e.date) }));
+
+  res.json({
+    data,
+    endCursor: data[data.length - 1]?.cursor,
+  });
+});
+
+export { router as eventsApiRouter };

src/admin/routes.ts

@@ -1,17 +1,31 @@
 import express, { Router } from "express";
-import { authorize } from "./auth";
+import { createWhitelistMiddleware } from "../shared/cidr";
 import { HttpError } from "../shared/errors";
+import { injectCsrfToken, checkCsrfToken } from "../shared/inject-csrf";
 import { injectLocals } from "../shared/inject-locals";
 import { withSession } from "../shared/with-session";
-import { injectCsrfToken, checkCsrfToken } from "../shared/inject-csrf";
+import { config } from "../config";
 import { renderPage } from "../info-page";
 import { buildInfo } from "../service-info";
+import { authorize } from "./auth";
 import { loginRouter } from "./login";
-import { usersApiRouter as apiRouter } from "./api/users";
+import { eventsApiRouter } from "./api/events";
+import { usersApiRouter } from "./api/users";
 import { usersWebRouter as webRouter } from "./web/manage";
+import { logger } from "../logger";
 
 const adminRouter = Router();
 
+const whitelist = createWhitelistMiddleware(
+  "ADMIN_WHITELIST",
+  config.adminWhitelist
+);
+
+if (!whitelist.ranges.length && config.adminKey?.length) {
+  logger.error("ADMIN_WHITELIST is empty. No admin requests will be allowed. Set 0.0.0.0/0 to allow all.");
+}
+
+adminRouter.use(whitelist);
 adminRouter.use(
   express.json({ limit: "20mb" }),
   express.urlencoded({ extended: true, limit: "20mb" })
@@ -19,7 +33,8 @@ adminRouter.use(
 adminRouter.use(withSession);
 adminRouter.use(injectCsrfToken);
 
-adminRouter.use("/users", authorize({ via: "header" }), apiRouter);
+adminRouter.use("/users", authorize({ via: "header" }), usersApiRouter);
+adminRouter.use("/events", authorize({ via: "header" }), eventsApiRouter);
 
 adminRouter.use(checkCsrfToken);
 adminRouter.use(injectLocals);

src/admin/web/manage.ts

@@ -1,4 +1,5 @@
 import { Router } from "express";
+import ipaddr from "ipaddr.js";
 import multer from "multer";
 import { z } from "zod";
 import { config } from "../../config";
@@ -6,7 +7,7 @@ import { HttpError } from "../../shared/errors";
 import * as userStore from "../../shared/users/user-store";
 import { parseSort, sortBy, paginate } from "../../shared/utils";
 import { keyPool } from "../../shared/key-management";
-import { MODEL_FAMILIES } from "../../shared/models";
+import { LLMService, MODEL_FAMILIES } from "../../shared/models";
 import { getTokenCostUsd, prettyTokens } from "../../shared/stats";
 import {
   User,
@@ -14,6 +15,9 @@ import {
   UserSchema,
   UserTokenCounts,
 } from "../../shared/users/schema";
+import { getLastNImages } from "../../shared/file-storage/image-history";
+import { blacklists, parseCidrs, whitelists } from "../../shared/cidr";
+import { invalidatePowChallenges } from "../../user/web/pow-captcha";
 
 const router = Router();
 
@@ -39,6 +43,74 @@ router.get("/create-user", (req, res) => {
   });
 });
 
+router.get("/anti-abuse", (_req, res) => {
+  const wl = [...whitelists.entries()];
+  const bl = [...blacklists.entries()];
+
+  res.render("admin_anti-abuse", {
+    captchaMode: config.captchaMode,
+    difficulty: config.powDifficultyLevel,
+    whitelists: wl.map((w) => ({
+      name: w[0],
+      mode: "whitelist",
+      ranges: w[1].ranges,
+    })),
+    blacklists: bl.map((b) => ({
+      name: b[0],
+      mode: "blacklist",
+      ranges: b[1].ranges,
+    })),
+  });
+});
+
+router.post("/cidr", (req, res) => {
+  const body = req.body;
+  const valid = z
+    .object({
+      action: z.enum(["add", "remove"]),
+      mode: z.enum(["whitelist", "blacklist"]),
+      name: z.string().min(1),
+      mask: z.string().min(1),
+    })
+    .safeParse(body);
+
+  if (!valid.success) {
+    throw new HttpError(
+      400,
+      valid.error.issues.flatMap((issue) => issue.message).join(", ")
+    );
+  }
+
+  const { mode, name, mask } = valid.data;
+  const list = (mode === "whitelist" ? whitelists : blacklists).get(name);
+  if (!list) {
+    throw new HttpError(404, "List not found");
+  }
+  if (valid.data.action === "remove") {
+    const newRanges = new Set(list.ranges);
+    newRanges.delete(mask);
+    list.updateRanges([...newRanges]);
+    req.session.flash = {
+      type: "success",
+      message: `${mode} ${name} updated`,
+    };
+    return res.redirect("/admin/manage/anti-abuse");
+  } else if (valid.data.action === "add") {
+    const result = parseCidrs(mask);
+    if (result.length === 0) {
+      throw new HttpError(400, "Invalid CIDR mask");
+    }
+
+    const newRanges = new Set([...list.ranges, mask]);
+    list.updateRanges([...newRanges]);
+    req.session.flash = {
+      type: "success",
+      message: `${mode} ${name} updated`,
+    };
+    return res.redirect("/admin/manage/anti-abuse");
+  }
+});
+
 router.post("/create-user", (req, res) => {
   const body = req.body;
 
@@ -196,13 +268,21 @@ router.post("/maintenance", (req, res) => {
   let flash = { type: "", message: "" };
   switch (action) {
     case "recheck": {
-      keyPool.recheck("openai");
-      keyPool.recheck("anthropic");
-      const size = keyPool
+      const checkable: LLMService[] = [
+        "openai",
+        "anthropic",
+        "aws",
+        "gcp",
+        "azure",
+        "google-ai"
+      ];
+      checkable.forEach((s) => keyPool.recheck(s));
+      const keyCount = keyPool
         .list()
-        .filter((k) => k.service !== "google-ai").length;
+        .filter((k) => checkable.includes(k.service)).length;
+
       flash.type = "success";
-      flash.message = `Scheduled recheck of ${size} keys for OpenAI and Anthropic.`;
+      flash.message = `Scheduled recheck of ${keyCount} keys.`;
       break;
     }
     case "resetQuotas": {
@@ -220,14 +300,139 @@ router.post("/maintenance", (req, res) => {
       flash.message = `All users' token usage records reset.`;
       break;
     }
+    case "downloadImageMetadata": {
+      const data = JSON.stringify(
+        {
+          exportedAt: new Date().toISOString(),
+          generations: getLastNImages(),
+        },
+        null,
+        2
+      );
+      res.setHeader(
+        "Content-Disposition",
+        `attachment; filename=image-metadata-${new Date().toISOString()}.json`
+      );
+      res.setHeader("Content-Type", "application/json");
+      return res.send(data);
+    }
+    case "expireTempTokens": {
+      const users = userStore.getUsers();
+      const temps = users.filter((u) => u.type === "temporary");
+      temps.forEach((user) => {
+        user.expiresAt = Date.now();
+        user.disabledReason = "Admin forced expiration.";
+        userStore.upsertUser(user);
+      });
+      invalidatePowChallenges();
+      flash.type = "success";
+      flash.message = `${temps.length} temporary users marked for expiration.`;
+      break;
+    }
+    case "cleanTempTokens": {
+      const users = userStore.getUsers();
+      const disabledTempUsers = users.filter(
+        (u) => u.type === "temporary" && u.expiresAt && u.expiresAt < Date.now()
+      );
+      disabledTempUsers.forEach((user) => {
+        user.disabledAt = 1; //will be cleaned up by the next cron job
+        userStore.upsertUser(user);
+      });
+      flash.type = "success";
+      flash.message = `${disabledTempUsers.length} disabled temporary users marked for cleanup.`;
+      break;
+    }
+    case "setDifficulty": {
+      const selected = req.body["pow-difficulty"];
+      const valid = ["low", "medium", "high", "extreme"];
+      const isNumber = Number.isInteger(Number(selected));
+      if (!selected || !valid.includes(selected) && !isNumber) {
+        throw new HttpError(400, "Invalid difficulty " + selected);
+      }
+      config.powDifficultyLevel = isNumber ? Number(selected) : selected;
+      invalidatePowChallenges();
+      break;
+    }
+    case "generateTempIpReport": {
+      const tempUsers = userStore
+        .getUsers()
+        .filter((u) => u.type === "temporary");
+      const ipv4RangeMap = new Map<string, Set<string>>();
+      const ipv6RangeMap = new Map<string, Set<string>>();
+
+      tempUsers.forEach((u) => {
+        u.ip.forEach((ip) => {
+          try {
+            const parsed = ipaddr.parse(ip);
+            if (parsed.kind() === "ipv4") {
+              const subnet =
+                parsed.toNormalizedString().split(".").slice(0, 3).join(".") +
+                ".0/24";
+              const userSet = ipv4RangeMap.get(subnet) || new Set();
+              userSet.add(u.token);
+              ipv4RangeMap.set(subnet, userSet);
+            } else if (parsed.kind() === "ipv6") {
+              const subnet =
+                parsed.toNormalizedString().split(":").slice(0, 4).join(":") +
+                "::/48";
+              const userSet = ipv6RangeMap.get(subnet) || new Set();
+              userSet.add(u.token);
+              ipv6RangeMap.set(subnet, userSet);
+            }
+          } catch (e) {
+            req.log.warn(
+              { ip, error: e.message },
+              "Invalid IP address; skipping"
+            );
+          }
+        });
+      });
+
+      const ipv4Ranges = Array.from(ipv4RangeMap.entries())
+        .map(([subnet, userSet]) => ({
+          subnet,
+          distinctTokens: userSet.size,
+        }))
+        .sort((a, b) => b.distinctTokens - a.distinctTokens);
+
+      const ipv6Ranges = Array.from(ipv6RangeMap.entries())
+        .map(([subnet, userSet]) => ({
+          subnet,
+          distinctTokens: userSet.size,
+        }))
+        .sort((a, b) => {
+          if (a.distinctTokens === b.distinctTokens) {
+            return a.subnet.localeCompare(b.subnet);
+          }
+          return b.distinctTokens - a.distinctTokens;
+        });
+
+      const data = JSON.stringify(
+        {
+          exportedAt: new Date().toISOString(),
+          ipv4Ranges,
+          ipv6Ranges,
+        },
+        null,
+        2
+      );
+
+      res.setHeader(
+        "Content-Disposition",
+        `attachment; filename=temp-ip-report-${new Date().toISOString()}.json`
+      );
+      res.setHeader("Content-Type", "application/json");
+      return res.send(data);
+    }
     default: {
       throw new HttpError(400, "Invalid action");
     }
   }
 
   req.session.flash = flash;
+  const referer = req.get("referer");
 
-  return res.redirect(`/admin/manage`);
+  return res.redirect(referer || "/admin/manage");
 });
 
 router.get("/download-stats", (_req, res) => {

src/admin/web/views/admin_anti-abuse.ejs

@@ -0,0 +1,160 @@
+<%- include("partials/shared_header", { title: "Proof of Work Verification Settings - OAI Reverse Proxy Admin" }) %>
+<style>
+  details {
+    margin-top: 1em;
+  }
+  details summary {
+    font-weight: bold;
+    cursor: pointer;
+  }
+  details p {
+    margin-left: 1em;
+  }
+
+  #token-manage {
+    display: flex;
+    width: 100%;
+  }
+  #token-manage button {
+    flex-grow: 1;
+    margin: 0 0.5em;
+  }
+</style>
+
+<h1>Abuse Mitigation Settings</h1>
+<div>
+  <h2>Proof-of-Work Verification</h2>
+  <p>
+    The Proof-of-Work difficulty level is used to determine how much work a client must perform to earn a temporary user
+    token. Higher difficulty levels require more work, which can help mitigate abuse by making it more expensive for
+    attackers to generate tokens. However, higher difficulty levels can also make it more difficult for legitimate users
+    to generate tokens. Refer to documentation for guidance.
+  </p>
+  <%if (captchaMode === "none") { %>
+  <p>
+    <strong>PoW verification is not enabled. Set <code>CAPTCHA_MODE=proof_of_work</code> to enable.</strong>
+  </p>
+  <% } else { %>
+  <h3>Difficulty Level</h3>
+  <div>
+    <label for="difficulty">Difficulty Level:</label>
+    <select name="difficulty" id="difficulty" onchange="difficultyChanged(event)">
+      <option value="low">Low</option>
+      <option value="medium">Medium</option>
+      <option value="high">High</option>
+      <option value="extreme">Extreme</option>
+      <option value="custom">Custom</option>
+    </select>
+    <div id="custom-difficulty-container" style="display: none">
+      <label for="customDifficulty">Hashes required (average):</label>
+      <input type="number" id="customDifficulty" value="0" min="1" max="1000000000" />
+    </div>
+    <button onclick='doAction("setDifficulty")'>Update Difficulty</button>
+  </div>
+  <div><span id="currentDifficulty">Current Difficulty: <%= difficulty %></span></div>
+  <% } %>
+  <form id="maintenanceForm" action="/admin/manage/maintenance" method="post">
+    <input id="_csrf" type="hidden" name="_csrf" value="<%= csrfToken %>" />
+    <input id="hiddenAction" type="hidden" name="action" value="" />
+    <input id="hiddenDifficulty" type="hidden" name="pow-difficulty" value="" />
+  </form>
+  <h3>Manage Temporary User Tokens</h3>
+  <div id="token-manage">
+    <p><button onclick='doAction("expireTempTokens")'>🕒 Expire All Temp Tokens</button></p>
+    <p><button onclick='doAction("cleanTempTokens")'>🧹 Delete Expired Temp Tokens</button></p>
+    <p><button onclick='doAction("generateTempIpReport")'>📊 Generate Temp Token IP Report</button></p>
+  </div>
+</div>
+<div>
+  <h2>IP Whitelists and Blacklists</h2>
+  <p>
+    You can specify IP ranges to whitelist or blacklist from accessing the proxy. Entries can be specified as single
+    addresses or
+    <a href="https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#CIDR_notation">CIDR notation</a>. IPv6 is
+    supported but not recommended for use with the current version of the proxy.
+  </p>
+  <p>
+    <strong>Note:</strong> Changes here are not persisted across server restarts. If you want to make changes permanent,
+    you can copy the values to your deployment configuration.
+  </p>
+  <% for (let i = 0; i < whitelists.length; i++) { %>
+  <%- include("partials/admin-cidr-widget", { list: whitelists[i] }) %>
+  <% } %>
+  <% for (let i = 0; i < blacklists.length; i++) { %>
+  <%- include("partials/admin-cidr-widget", { list: blacklists[i] }) %>
+  <% } %>
+  <form action="/admin/manage/cidr" method="post" id="cidrForm">
+    <input id="_csrf" type="hidden" name="_csrf" value="<%= csrfToken %>" />
+    <input type="hidden" name="action" value="add" />
+    <input type="hidden" name="name" value="" />
+    <input type="hidden" name="mode" value="" />
+    <input type="hidden" name="mask" value="" />
+  </form>
+  <details>
+    <summary>Copy environment variables</summary>
+    <p>
+      If you have made changes with the UI, you can copy the values below to your deployment configuration to persist
+      them across server restarts.
+    </p>
+    <pre>
+    <% for (let i = 0; i < whitelists.length; i++) { %><%= whitelists[i].name %>=<%= whitelists[i].ranges.join(",") %><% } %>
+    <% for (let i = 0; i < blacklists.length; i++) { %><%= blacklists[i].name %>=<%= blacklists[i].ranges.join(",") %><% } %>
+    </pre>
+  </details>
+</div>
+
+<script>
+  function difficultyChanged(event) {
+    const value = event.target.value;
+    if (value === "custom") {
+      document.getElementById("custom-difficulty-container").style.display = "block";
+    } else {
+      document.getElementById("custom-difficulty-container").style.display = "none";
+    }
+  }
+
+  function doAction(action) {
+    document.getElementById("hiddenAction").value = action;
+    if (action === "setDifficulty") {
+      const selected = document.getElementById("difficulty").value;
+      const hiddenDifficulty = document.getElementById("hiddenDifficulty");
+      if (selected === "custom") {
+        hiddenDifficulty.value = document.getElementById("customDifficulty").value;
+      } else {
+        hiddenDifficulty.value = selected;
+      }
+    }
+    document.getElementById("maintenanceForm").submit();
+  }
+
+  function onAddCidr(event) {
+    const list = event.target.dataset;
+    const newMask = prompt("Enter the IP or CIDR range to add to the list:");
+    if (!newMask) {
+      return;
+    }
+
+    const form = document.getElementById("cidrForm");
+    form["action"].value = "add";
+    form["name"].value = list.name;
+    form["mode"].value = list.mode;
+    form["mask"].value = newMask;
+    form.submit();
+  }
+
+  function onRemoveCidr(event) {
+    const list = event.target.dataset;
+    const removeMask = event.target.dataset.mask;
+    if (!removeMask) {
+      return;
+    }
+
+    const form = document.getElementById("cidrForm");
+    form["action"].value = "remove";
+    form["name"].value = list.name;
+    form["mode"].value = list.mode;
+    form["mask"].value = removeMask;
+    form.submit();
+  }
+</script>
+<%- include("partials/admin-footer") %>

src/admin/web/views/admin_create-user.ejs

@@ -51,9 +51,8 @@
     <legend>Temporary User Options</legend>
     <div class="temporary-user-fieldset">
       <p class="full-width">
-        Temporary users will be disabled after the specified duration, and their records will be deleted 72 hours after that.
-        These options apply only to new
-        temporary users; existing ones use whatever options were in effect when they were created.
+        Temporary users will be disabled after the specified duration, and their records will be permanently deleted after some time.
+        These options apply only to new temporary users; existing ones use whatever options were in effect when they were created.
       </p>
       <label for="temporaryUserDuration" class="full-width">Access duration (in minutes)</label>
       <input type="number" name="temporaryUserDuration" id="temporaryUserDuration" value="60" class="full-width" />

src/admin/web/views/admin_download-stats.ejs

@@ -5,18 +5,6 @@
     flex-direction: column;
   }
 
-  #statsForm div {
-    display: flex;
-    flex-direction: row;
-    margin-bottom: 0.5em;
-  }
-
-  #statsForm div label {
-    width: 6em;
-    text-align: right;
-    margin-right: 1em;
-  }
-
   #statsForm ul {
     margin: 0;
     padding-left: 2em;
@@ -33,17 +21,17 @@
   }
 </style>
 <h1>Download Stats</h1>
-<p>
-  Download usage statistics to a Markdown document. You can paste this into a service like Rentry.org to share it.
-</p>
+<p>Download usage statistics to a Markdown document. You can paste this into a service like Rentry.org to share it.</p>
 <div>
   <h3>Options</h3>
-  <form id="statsForm" action="/admin/manage/generate-stats" method="post"
-    style="display: flex; flex-direction: column;">
+  <form
+    id="statsForm"
+    action="/admin/manage/generate-stats"
+    method="post"
+    style="display: flex; flex-direction: column">
     <input id="_csrf" type="hidden" name="_csrf" value="<%= csrfToken %>" />
     <div>
-      <label for="anon">Anonymize</label>
-      <input id="anon" type="checkbox" name="anon" value="true" />
+      <label for="anon"><input id="anon" type="checkbox" name="anon" value="true" /> <span>Anonymize</span></label>
     </div>
     <div>
       <label for="sort">Sort</label>
@@ -64,11 +52,12 @@
       </select>
     </div>
     <div>
-      <label for="format">Custom Format <ul>
-          <li><code>{{header}}</code></li>
-          <li><code>{{stats}}</code></li>
-          <li><code>{{time}}</code></li>
-        </ul></label>
+      <label for="format">Custom Format</label>
+      <ul>
+        <li><code>{{header}}</code></li>
+        <li><code>{{stats}}</code></li>
+        <li><code>{{time}}</code></li>
+      </ul>
       <textarea id="format" name="format" rows="10" cols="50" placeholder="{{stats}}">
 # Stats
 {{header}}
@@ -115,33 +104,35 @@
   loadDefaults();
 
   async function fetchAndCopy() {
-    const form = document.getElementById('statsForm');
+    const form = document.getElementById("statsForm");
     const formData = new FormData(form);
 
     const response = await fetch(form.action, {
-      method: 'POST',
-      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
-      credentials: 'same-origin',
+      method: "POST",
+      headers: { "Content-Type": "application/x-www-form-urlencoded" },
+      credentials: "same-origin",
       body: new URLSearchParams(formData),
     });
 
-
     if (response.ok) {
       const content = await response.text();
       copyToClipboard(content);
     } else {
-      throw new Error('Failed to fetch generated stats. Try reloading the page.');
+      throw new Error("Failed to fetch generated stats. Try reloading the page.");
     }
   }
 
   function copyToClipboard(text) {
-    navigator.clipboard.writeText(text).then(() => {
-      alert('Copied to clipboard');
-    }).catch(err => {
-      alert('Failed to copy to clipboard. Try downloading the file instead.');
-    });
+    navigator.clipboard
+      .writeText(text)
+      .then(() => {
+        alert("Copied to clipboard");
+      })
+      .catch((err) => {
+        alert("Failed to copy to clipboard. Try downloading the file instead.");
+      });
   }
 
-  document.getElementById('copyButton').addEventListener('click', fetchAndCopy);
+  document.getElementById("copyButton").addEventListener("click", fetchAndCopy);
 </script>
 <%- include("partials/admin-footer") %>

src/admin/web/views/admin_index.ejs

@@ -25,13 +25,14 @@
   <li><a href="/admin/manage/import-users">Import Users</a></li>
   <li><a href="/admin/manage/export-users">Export Users</a></li>
   <li><a href="/admin/manage/download-stats">Download Rentry Stats</a>
+  <li><a href="/admin/manage/anti-abuse">Abuse Mitigation Settings</a></li>
   <li><a href="/admin/service-info">Service Info</a></li>
 </ul>
 <h3>Maintenance</h3>
 <form id="maintenanceForm" action="/admin/manage/maintenance" method="post">
   <input id="_csrf" type="hidden" name="_csrf" value="<%= csrfToken %>" />
   <input id="hiddenAction" type="hidden" name="action" value="" />
-  <div display="flex" flex-direction="column">
+  <div>
     <fieldset>
       <legend>Key Recheck</legend>
       <button id="recheck-keys" type="button" onclick="submitForm('recheck')">Force Key Recheck</button>
@@ -42,7 +43,7 @@
       <legend>Bulk Quota Management</legend>
       <p>
         <button id="refresh-quotas" type="button" onclick="submitForm('resetQuotas')">Refresh All Quotas</button>
-        Resets all users' quotas to the values set in the <code>TOKEN_QUOTA_*</code> environment variables.
+        Immediately refreshes all users' quotas by the configured amounts.
       </p>
       <p>
         <button id="clear-token-counts" type="button" onclick="submitForm('resetCounts')">Clear All Token Counts</button>
@@ -50,6 +51,13 @@
       </p>
     </fieldset>
     <% } %>
+    <% if (imageGenerationEnabled) { %>
+    <fieldset>
+      <legend>Image Generation</legend>
+      <button id="download-image-metadata" type="button" onclick="submitForm('downloadImageMetadata')">Download Image Metadata</button>
+      <label for="download-image-metadata">Downloads a metadata file containing URL, prompt, and truncated user token for all cached images.</label>
+    </fieldset>
+    <% } %>
   </div>
 </form>
 

src/admin/web/views/admin_list-users.ejs

@@ -4,9 +4,8 @@
     <% if (users.length === 0) { %>
     <p>No users found.</p>
     <% } else { %>
-    <input type="checkbox" id="toggle-nicknames" onchange="toggleNicknames()" />
-    <label for="toggle-nicknames">Show Nicknames</label>
-    <table>
+    <label for="toggle-nicknames"><input type="checkbox" id="toggle-nicknames" onchange="toggleNicknames()" /> Show Nicknames</label>
+    <table class="striped full-width">
       <thead>
         <tr>
           <th>User</th>

src/admin/web/views/admin_view-user.ejs

@@ -55,8 +55,9 @@
       <td><%- user.disabledReason %></td>
       <% if (user.disabledAt) { %>
       <td class="actions">
-        <a title="Edit" id="edit-disabledReason" href="#" data-field="disabledReason"
-          data-token="<%= user.token %>">✏️</a>
+        <a title="Edit" id="edit-disabledReason" href="#" data-field="disabledReason" data-token="<%= user.token %>"
+          >✏️</a
+        >
       </td>
       <% } %>
     </tr>
@@ -72,7 +73,8 @@
       <td colspan="2"><%- include("partials/shared_user_ip_list", { user, shouldRedact: false }) %></td>
     </tr>
     <tr>
-      <th scope="row">Admin Note <span title="Unlike nickname, this is not visible to or editable by the user">🔒</span>
+      <th scope="row">
+        Admin Note <span title="Unlike nickname, this is not visible to or editable by the user">🔒</span>
       </th>
       <td><%- user.adminNote ?? "none" %></td>
       <td class="actions">
@@ -85,14 +87,24 @@
       <td colspan="2"><%- user.expiresAt %></td>
     </tr>
     <% } %>
+    <% if (user.meta) { %>
+    <tr>
+      <th scope="row">Meta</th>
+      <td colspan="2"><%- JSON.stringify(user.meta) %></td>
+    </tr>
+    <% } %>
   </tbody>
 </table>
 
-<form style="display:none" id="current-values">
+<form style="display: none" id="current-values">
   <input type="hidden" name="token" value="<%- user.token %>" />
   <% ["nickname", "type", "disabledAt", "disabledReason", "maxIps", "adminNote"].forEach(function (key) { %>
   <input type="hidden" name="<%- key %>" value="<%- user[key] %>" />
   <% }); %>
+  <!-- tokenRefresh_ keys are dynamically generated -->
+  <% Object.entries(quota).forEach(([family]) => { %>
+  <input type="hidden" name="tokenRefresh_<%- family %>" value="<%- user.tokenRefresh[family] || quota[family] %>" />
+  <% }); %>
 </form>
 
 <h3>Quota Information</h3>
@@ -102,7 +114,8 @@
   <input type="hidden" name="_csrf" value="<%- csrfToken %>" />
   <button type="submit" class="btn btn-primary">Refresh Quotas for User</button>
 </form>
-<% } %> <%- include("partials/shared_quota-info", { quota, user }) %>
+<% } %>
+<%- include("partials/shared_quota-info", { quota, user, showRefreshEdit: true }) %>
 
 <p><a href="/admin/manage/list-users">Back to User List</a></p>
 
@@ -113,18 +126,25 @@
       const token = a.dataset.token;
       const field = a.dataset.field;
       const existingValue = document.querySelector(`#current-values input[name=${field}]`).value;
-      let value = prompt(`Enter new value for '${field}'':`, existingValue);
+
+      let value = prompt(`Enter new value for '${field}':`, existingValue);
       if (value !== null) {
         if (value === "") {
           value = null;
         }
+
+        const payload = { _csrf: document.querySelector("meta[name=csrf-token]").getAttribute("content") };
+        if (field.startsWith("tokenRefresh_")) {
+          const family = field.slice("tokenRefresh_".length);
+          payload.tokenRefresh = { [family]: Number(value) };
+        } else {
+          payload[field] = value;
+        }
+
         fetch(`/admin/manage/edit-user/${token}`, {
           method: "POST",
           credentials: "same-origin",
-          body: JSON.stringify({
-            [field]: value,
-            _csrf: document.querySelector("meta[name=csrf-token]").getAttribute("content"),
-          }),
+          body: JSON.stringify(payload),
           headers: { "Content-Type": "application/json", Accept: "application/json" },
         })
           .then((res) => Promise.all([res.ok, res.json()]))
@@ -132,9 +152,7 @@
             const url = new URL(window.location.href);
             const params = new URLSearchParams();
             if (!ok) {
-              params.set("flash", `error: ${json.error.message}`);
-            } else {
-              params.set("flash", `success: User's ${field} updated.`);
+              alert(`Failed to edit user: ${json.message}`);
             }
             url.search = params.toString();
             window.location.assign(url);
@@ -144,4 +162,5 @@
   });
 </script>
 
-<%- include("partials/admin-ban-xhr-script") %> <%- include("partials/admin-footer") %>
+<%- include("partials/admin-ban-xhr-script") %>
+<%- include("partials/admin-footer") %>

src/admin/web/views/partials/admin-cidr-widget.ejs

@@ -0,0 +1,13 @@
+<h3>
+  <%= list.name %>
+  (<%= list.mode %>)
+</h3>
+<ul>
+  <% list.ranges.forEach(function(mask) { %>
+  <li>
+    <%= mask %>
+    <button class="remove" data-mode="<%= list.mode %>" data-name="<%= list.name %>" data-mask="<%= mask %>" onclick="onRemoveCidr(event)">Remove</button>
+  </li>
+  <% }); %>
+</ul>
+<button class="add" data-mode="<%= list.mode %>" data-name="<%= list.name %>" onclick="onAddCidr(event)">Add</button>

src/config.ts

@@ -1,8 +1,9 @@
+import crypto from "crypto";
 import dotenv from "dotenv";
 import type firebase from "firebase-admin";
 import path from "path";
 import pino from "pino";
-import type { ModelFamily } from "./shared/models";
+import type { LLMService, ModelFamily } from "./shared/models";
 import { MODEL_FAMILIES } from "./shared/models";
 
 dotenv.config();
@@ -16,6 +17,8 @@ export const USER_ASSETS_DIR = path.join(DATA_DIR, "user-files");
 type Config = {
   /** The port the proxy server will listen on. */
   port: number;
+  /** The network interface the proxy server will listen on. */
+  bindAddress: string;
   /** Comma-delimited list of OpenAI API keys. */
   openaiKey?: string;
   /** Comma-delimited list of Anthropic API keys. */
@@ -42,6 +45,13 @@ type Config = {
    * @example `AWS_CREDENTIALS=access_key_1:secret_key_1:us-east-1,access_key_2:secret_key_2:us-west-2`
    */
   awsCredentials?: string;
+  /**
+   * Comma-delimited list of GCP credentials. Each credential item should be a
+   * colon-delimited list of access key, secret key, and GCP region.
+   *
+   * @example `GCP_CREDENTIALS=project1:1@1.com:us-east5:-----BEGIN PRIVATE KEY-----xxx-----END PRIVATE KEY-----,project2:2@2.com:us-east5:-----BEGIN PRIVATE KEY-----xxx-----END PRIVATE KEY-----`
+   */
+  gcpCredentials?: string;
   /**
    * Comma-delimited list of Azure OpenAI credentials. Each credential item
    * should be a colon-delimited list of Azure resource name, deployment ID, and
@@ -63,6 +73,11 @@ type Config = {
    * management mode is set to 'user_token'.
    */
   adminKey?: string;
+  /**
+   * The password required to view the service info/status page. If not set, the
+   * info page will be publicly accessible.
+   */
+  serviceInfoPassword?: string;
   /**
    * Which user management mode to use.
    * - `none`: No user management. Proxy is open to all requests with basic
@@ -100,9 +115,70 @@ type Config = {
    * `maxIpsPerUser` limit, or if only connections from new IPs are be rejected.
    */
   maxIpsAutoBan: boolean;
-  /** Per-IP limit for requests per minute to text and chat models. */
+  /**
+   * Which captcha verification mode to use. Requires `user_token` gatekeeper.
+   * Allows users to automatically obtain a token by solving a captcha.
+   * - `none`: No captcha verification; tokens are issued manually.
+   * - `proof_of_work`: Users must solve an Argon2 proof of work to obtain a
+   *    temporary usertoken valid for a limited period.
+   */
+  captchaMode: "none" | "proof_of_work";
+  /**
+   * Duration (in hours) for which a PoW-issued temporary user token is valid.
+   */
+  powTokenHours: number;
+  /**
+   * The maximum number of IPs from which a single temporary user token can be
+   * used. Upon reaching the limit, the `maxIpsAutoBan` behavior is triggered.
+   */
+  powTokenMaxIps: number;
+  /**
+   * Difficulty level for the proof-of-work challenge.
+   * - `low`: 200 iterations
+   * - `medium`: 900 iterations
+   * - `high`: 1900 iterations
+   * - `extreme`: 4000 iterations
+   * - `number`: A custom number of iterations to use.
+   *
+   * Difficulty level only affects the number of iterations used in the PoW,
+   * not the complexity of the hash itself. Therefore, the average time-to-solve
+   * will scale linearly with the number of iterations.
+   *
+   * Refer to docs/proof-of-work.md for guidance and hashrate benchmarks.
+   */
+  powDifficultyLevel: "low" | "medium" | "high" | "extreme" | number;
+  /**
+   * Duration (in minutes) before a PoW challenge expires. Users' browsers must
+   * solve the challenge within this time frame or it will be rejected. Should
+   * be kept somewhat low to prevent abusive clients from working on many
+   * challenges in parallel, but you may need to increase this value for higher
+   * difficulty levels or older devices will not be able to solve the challenge
+   * in time.
+   *
+   * Defaults to 30 minutes.
+   */
+  powChallengeTimeout: number;
+  /**
+   * Duration (in hours) before expired temporary user tokens are purged from
+   * the user database. Users can refresh expired tokens by solving a faster PoW
+   * challenge as long as the original token has not been purged. Once purged,
+   * the user must solve a full PoW challenge to obtain a new token.
+   *
+   * Defaults to 48 hours. At 0, tokens are purged immediately upon expiry.
+   */
+  powTokenPurgeHours: number;
+  /**
+   * Maximum number of active temporary user tokens that can be associated with
+   * a single IP address. Note that this may impact users sending requests from
+   * hosted AI chat clients such as Agnaistic or RisuAI, as they may share IPs.
+   *
+   * When the limit is reached, the oldest token with the same IP will be
+   * expired. At 0, no limit is enforced. Defaults to 0.
+   */
+  // powMaxTokensPerIp: number;
+  /** Per-user limit for requests per minute to text and chat models. */
   textModelRateLimit: number;
-  /** Per-IP limit for requests per minute to image generation models. */
+  /** Per-user limit for requests per minute to image generation models. */
   imageModelRateLimit: number;
   /**
    * For OpenAI, the maximum number of context tokens (prompt + max output) a
@@ -139,10 +215,38 @@ type Config = {
    * key and can't attach the policy, you can set this to true.
    */
   allowAwsLogging?: boolean;
+  /**
+   * Path to the SQLite database file for storing data such as event logs. By
+   * default, the database will be stored at `data/database.sqlite`.
+   *
+   * Ensure target is writable by the server process, and be careful not to
+   * select a path that is served publicly. The default path is safe.
+   */
+  sqliteDataPath?: string;
+  /**
+   * Whether to log events, such as generated completions, to the database.
+   * Events are associated with IP+user token pairs. If user_token mode is
+   * disabled, no events will be logged.
+   *
+   * Currently there is no pruning mechanism for the events table, so it will
+   * grow indefinitely. You may want to periodically prune the table manually.
+   */
+  eventLogging?: boolean;
+  /**
+   * When hashing prompt histories, how many messages to trim from the end.
+   * If zero, only the full prompt hash will be stored.
+   * If greater than zero, for each number N, a hash of the prompt with the
+   * last N messages removed will be stored.
+   *
+   * Experimental function, config may change in future versions.
+   */
+  eventLoggingTrim?: number;
   /** Whether prompts and responses should be logged to persistent storage. */
   promptLogging?: boolean;
   /** Which prompt logging backend to use. */
-  promptLoggingBackend?: "google_sheets";
+  promptLoggingBackend?: "google_sheets" | "file";
+  /** Prefix for prompt logging files when using the file backend. */
+  promptLoggingFilePrefix?: string;
   /** Base64-encoded Google Sheets API key. */
   googleSheetsKey?: string;
   /** Google Sheets spreadsheet ID. */
@@ -198,57 +302,173 @@ type Config = {
    * configured ADMIN_KEY and go to /admin/service-info.
    **/
   staticServiceInfo?: boolean;
+  /**
+   * Trusted proxy hops. If you are deploying the server behind a reverse proxy
+   * (Nginx, Cloudflare Tunnel, AWS WAF, etc.) the IP address of incoming
+   * requests will be the IP address of the proxy, not the actual user.
+   *
+   * Depending on your hosting configuration, there may be multiple proxies/load
+   * balancers between your server and the user. Each one will append the
+   * incoming IP address to the `X-Forwarded-For` header. The user's real IP
+   * address will be the first one in the list, assuming the header has not been
+   * tampered with. Setting this value correctly ensures that the server doesn't
+   * trust values in `X-Forwarded-For` not added by trusted proxies.
+   *
+   * In order for the server to determine the user's real IP address, you need
+   * to tell it how many proxies are between the user and the server so it can
+   * select the correct IP address from the `X-Forwarded-For` header.
+   *
+   * *WARNING:* If you set it incorrectly, the proxy will either record the
+   * wrong IP address, or it will be possible for users to spoof their IP
+   * addresses and bypass rate limiting. Check the request logs to see what
+   * incoming X-Forwarded-For values look like.
+   *
+   * Examples:
+   *  - X-Forwarded-For: "34.1.1.1, 172.1.1.1, 10.1.1.1" => trustedProxies: 3
+   *  - X-Forwarded-For: "34.1.1.1" => trustedProxies: 1
+   *  - no X-Forwarded-For header => trustedProxies: 0 (the actual IP of the incoming request will be used)
+   *
+   * As of 2024/01/08:
+   * For HuggingFace or Cloudflare Tunnel, use 1.
+   * For Render, use 3.
+   * For deployments not behind a load balancer, use 0.
+   *
+   * You should double check against your actual request logs to be sure.
+   *
+   * Defaults to 1, as most deployments are on HuggingFace or Cloudflare Tunnel.
+   */
+  trustedProxies?: number;
+  /**
+   * Whether to allow OpenAI tool usage.  The proxy doesn't impelment any
+   * support for tools/function calling but can pass requests and responses as
+   * is. Note that the proxy also cannot accurately track quota usage for
+   * requests involving tools, so you must opt in to this feature at your own
+   * risk.
+   */
+  allowOpenAIToolUsage?: boolean;
+  /**
+   * Which services will accept prompts containing images, for use with
+   * multimodal models. Users with `special` role are exempt from this
+   * restriction.
+   *
+   * Do not enable this feature for untrusted users, as malicious users could
+   * send images which violate your provider's terms of service or local laws.
+   *
+   * Defaults to no services, meaning image prompts are disabled. Use a comma-
+   * separated list. Available services are:
+   * openai,anthropic,google-ai,mistral-ai,aws,gcp,azure
+   */
+  allowedVisionServices: LLMService[];
+  /**
+   * Allows overriding the default proxy endpoint route. Defaults to /proxy.
+   * A leading slash is required.
+   */
+  proxyEndpointRoute: string;
+  /**
+   * If set, only requests from these IP addresses will be permitted to use the
+   * admin API and UI. Provide a comma-separated list of IP addresses or CIDR
+   * ranges. If not set, the admin API and UI will be open to all requests.
+   */
+  adminWhitelist: string[];
+  /**
+   * If set, requests from these IP addresses will be blocked from using the
+   * application. Provide a comma-separated list of IP addresses or CIDR ranges.
+   * If not set, no IP addresses will be blocked.
+   *
+   * Takes precedence over the adminWhitelist.
+   */
+  ipBlacklist: string[];
+  /**
+   * If set, pushes requests further back into the queue according to their
+   * token costs by factor*tokens*milliseconds (or more intuitively
+   * factor*thousands_of_tokens*seconds).
+   * Accepts floats.
+   */
+  tokensPunishmentFactor: number;
+  /**
+   * Configuration for HTTP requests made by the proxy to other servers, such
+   * as when checking keys or forwarding users' requests to external services.
+   * If not set, all requests will be made using the default agent.
+   *
+   * If set, the proxy may make requests to other servers using the specified
+   * settings. This is useful if you wish to route users' requests through
+   * another proxy or VPN, or if you have multiple network interfaces and want
+   * to use a specific one for outgoing requests.
+   */
+  httpAgent?: {
+    /**
+     * The name of the network interface to use. The first external IPv4 address
+     * belonging to this interface will be used for outgoing requests.
+     */
+    interface?: string;
+    /**
+     * The URL of a proxy server to use. Supports SOCKS4, SOCKS5, HTTP, and
+     * HTTPS. If not set, the proxy will be made using the default agent.
+     * - SOCKS4: `socks4://some-socks-proxy.com:9050`
+     * - SOCKS5: `socks5://username:password@some-socks-proxy.com:9050`
+     * - HTTP: `http://proxy-server-over-tcp.com:3128`
+     * - HTTPS: `https://proxy-server-over-tls.com:3129`
+     *
+     * **Note:** If your proxy server issues a certificate, you may need to set
+     * `NODE_EXTRA_CA_CERTS` to the path to your certificate, otherwise this
+     * application will reject TLS connections.
+     */
+    proxyUrl?: string;
+  };
 };
 
 // To change configs, create a file called .env in the root directory.
 // See .env.example for an example.
 export const config: Config = {
   port: getEnvWithDefault("PORT", 7860),
+  bindAddress: getEnvWithDefault("BIND_ADDRESS", "0.0.0.0"),
   openaiKey: getEnvWithDefault("OPENAI_KEY", ""),
   anthropicKey: getEnvWithDefault("ANTHROPIC_KEY", ""),
   googleAIKey: getEnvWithDefault("GOOGLE_AI_KEY", ""),
   mistralAIKey: getEnvWithDefault("MISTRAL_AI_KEY", ""),
   awsCredentials: getEnvWithDefault("AWS_CREDENTIALS", ""),
+  gcpCredentials: getEnvWithDefault("GCP_CREDENTIALS", ""),
   azureCredentials: getEnvWithDefault("AZURE_CREDENTIALS", ""),
   proxyKey: getEnvWithDefault("PROXY_KEY", ""),
   adminKey: getEnvWithDefault("ADMIN_KEY", ""),
+  serviceInfoPassword: getEnvWithDefault("SERVICE_INFO_PASSWORD", ""),
+  sqliteDataPath: getEnvWithDefault(
+    "SQLITE_DATA_PATH",
+    path.join(DATA_DIR, "database.sqlite")
+  ),
+  eventLogging: getEnvWithDefault("EVENT_LOGGING", false),
+  eventLoggingTrim: getEnvWithDefault("EVENT_LOGGING_TRIM", 5),
   gatekeeper: getEnvWithDefault("GATEKEEPER", "none"),
   gatekeeperStore: getEnvWithDefault("GATEKEEPER_STORE", "memory"),
   maxIpsPerUser: getEnvWithDefault("MAX_IPS_PER_USER", 0),
-  maxIpsAutoBan: getEnvWithDefault("MAX_IPS_AUTO_BAN", true),
+  maxIpsAutoBan: getEnvWithDefault("MAX_IPS_AUTO_BAN", false),
+  captchaMode: getEnvWithDefault("CAPTCHA_MODE", "none"),
+  powTokenHours: getEnvWithDefault("POW_TOKEN_HOURS", 24),
+  powTokenMaxIps: getEnvWithDefault("POW_TOKEN_MAX_IPS", 2),
+  powDifficultyLevel: getEnvWithDefault("POW_DIFFICULTY_LEVEL", "low"),
+  powChallengeTimeout: getEnvWithDefault("POW_CHALLENGE_TIMEOUT", 30),
+  powTokenPurgeHours: getEnvWithDefault("POW_TOKEN_PURGE_HOURS", 48),
   firebaseRtdbUrl: getEnvWithDefault("FIREBASE_RTDB_URL", undefined),
   firebaseKey: getEnvWithDefault("FIREBASE_KEY", undefined),
   textModelRateLimit: getEnvWithDefault("TEXT_MODEL_RATE_LIMIT", 4),
   imageModelRateLimit: getEnvWithDefault("IMAGE_MODEL_RATE_LIMIT", 4),
-  maxContextTokensOpenAI: getEnvWithDefault("MAX_CONTEXT_TOKENS_OPENAI", 16384),
+  maxContextTokensOpenAI: getEnvWithDefault("MAX_CONTEXT_TOKENS_OPENAI", 32768),
   maxContextTokensAnthropic: getEnvWithDefault(
     "MAX_CONTEXT_TOKENS_ANTHROPIC",
-    0
+    32768
   ),
   maxOutputTokensOpenAI: getEnvWithDefault(
     ["MAX_OUTPUT_TOKENS_OPENAI", "MAX_OUTPUT_TOKENS"],
-    400
+    1024
   ),
   maxOutputTokensAnthropic: getEnvWithDefault(
     ["MAX_OUTPUT_TOKENS_ANTHROPIC", "MAX_OUTPUT_TOKENS"],
-    400
+    1024
+  ),
+  allowedModelFamilies: getEnvWithDefault(
+    "ALLOWED_MODEL_FAMILIES",
+    getDefaultModelFamilies()
   ),
-  allowedModelFamilies: getEnvWithDefault("ALLOWED_MODEL_FAMILIES", [
-    "turbo",
-    "gpt4",
-    "gpt4-32k",
-    "gpt4-turbo",
-    "claude",
-    "gemini-pro",
-    "mistral-tiny",
-    "mistral-small",
-    "mistral-medium",
-    "aws-claude",
-    "azure-turbo",
-    "azure-gpt4",
-    "azure-gpt4-turbo",
-    "azure-gpt4-32k",
-  ]),
   rejectPhrases: parseCsv(getEnvWithDefault("REJECT_PHRASES", "")),
   rejectMessage: getEnvWithDefault(
     "REJECT_MESSAGE",
@@ -260,6 +480,10 @@ export const config: Config = {
   allowAwsLogging: getEnvWithDefault("ALLOW_AWS_LOGGING", false),
   promptLogging: getEnvWithDefault("PROMPT_LOGGING", false),
   promptLoggingBackend: getEnvWithDefault("PROMPT_LOGGING_BACKEND", undefined),
+  promptLoggingFilePrefix: getEnvWithDefault(
+    "PROMPT_LOGGING_FILE_PREFIX",
+    "prompt-logs"
+  ),
   googleSheetsKey: getEnvWithDefault("GOOGLE_SHEETS_KEY", undefined),
   googleSheetsSpreadsheetId: getEnvWithDefault(
     "GOOGLE_SHEETS_SPREADSHEET_ID",
@@ -286,19 +510,58 @@ export const config: Config = {
   showRecentImages: getEnvWithDefault("SHOW_RECENT_IMAGES", true),
   useInsecureCookies: getEnvWithDefault("USE_INSECURE_COOKIES", isDev),
   staticServiceInfo: getEnvWithDefault("STATIC_SERVICE_INFO", false),
+  trustedProxies: getEnvWithDefault("TRUSTED_PROXIES", 1),
+  allowOpenAIToolUsage: getEnvWithDefault("ALLOW_OPENAI_TOOL_USAGE", false),
+  allowedVisionServices: parseCsv(
+    getEnvWithDefault("ALLOWED_VISION_SERVICES", "")
+  ) as LLMService[],
+  proxyEndpointRoute: getEnvWithDefault("PROXY_ENDPOINT_ROUTE", "/proxy"),
+  adminWhitelist: parseCsv(
+    getEnvWithDefault("ADMIN_WHITELIST", "0.0.0.0/0,::/0")
+  ),
+  ipBlacklist: parseCsv(getEnvWithDefault("IP_BLACKLIST", "")),
+  tokensPunishmentFactor: getEnvWithDefault("TOKENS_PUNISHMENT_FACTOR", 0.0),
+  httpAgent: {
+    interface: getEnvWithDefault("HTTP_AGENT_INTERFACE", undefined),
+    proxyUrl: getEnvWithDefault("HTTP_AGENT_PROXY_URL", undefined),
+  },
 } as const;
 
-function generateCookieSecret() {
+function generateSigningKey() {
   if (process.env.COOKIE_SECRET !== undefined) {
+    // legacy, replaced by SIGNING_KEY
     return process.env.COOKIE_SECRET;
+  } else if (process.env.SIGNING_KEY !== undefined) {
+    return process.env.SIGNING_KEY;
   }
 
-  const seed = "" + config.adminKey + config.openaiKey + config.anthropicKey;
-  const crypto = require("crypto");
+  const secrets = [
+    config.adminKey,
+    config.openaiKey,
+    config.anthropicKey,
+    config.googleAIKey,
+    config.mistralAIKey,
+    config.awsCredentials,
+    config.gcpCredentials,
+    config.azureCredentials,
+  ];
+  if (secrets.filter((s) => s).length === 0) {
+    startupLogger.warn(
+      "No SIGNING_KEY or secrets are set. All sessions, cookies, and proofs of work will be invalidated on restart."
+    );
+    return crypto.randomBytes(32).toString("hex");
+  }
+
+  startupLogger.info("No SIGNING_KEY set; one will be generated from secrets.");
+  startupLogger.info(
+    "It's recommended to set SIGNING_KEY explicitly to ensure users' sessions and cookies always persist across restarts."
+  );
+  const seed = secrets.map((s) => s || "n/a").join("");
   return crypto.createHash("sha256").update(seed).digest("hex");
 }
 
-export const COOKIE_SECRET = generateCookieSecret();
+const signingKey = generateSigningKey();
+export const SECRET_SIGNING_KEY = signingKey;
 
 export async function assertConfigIsValid() {
   if (process.env.MODEL_RATE_LIMIT !== undefined) {
@@ -314,6 +577,23 @@ export async function assertConfigIsValid() {
     );
   }
 
+  if (process.env.ALLOW_IMAGE_PROMPTS === "true") {
+    const hasAllowedServices = config.allowedVisionServices.length > 0;
+    if (!hasAllowedServices) {
+      config.allowedVisionServices = ["openai", "anthropic"];
+      startupLogger.warn(
+        { allowedVisionServices: config.allowedVisionServices },
+        "ALLOW_IMAGE_PROMPTS is deprecated. Use ALLOWED_VISION_SERVICES instead."
+      );
+    }
+  }
+
+  if (config.promptLogging && !config.promptLoggingBackend) {
+    throw new Error(
+      "Prompt logging is enabled but no backend is configured. Set PROMPT_LOGGING_BACKEND to 'google_sheets' or 'file'."
+    );
+  }
+
   if (!["none", "proxy_key", "user_token"].includes(config.gatekeeper)) {
     throw new Error(
       `Invalid gatekeeper mode: ${config.gatekeeper}. Must be one of: none, proxy_key, user_token.`
@@ -326,15 +606,32 @@ export async function assertConfigIsValid() {
     );
   }
 
-  if (config.gatekeeper === "proxy_key" && !config.proxyKey) {
+  if (
+    config.captchaMode === "proof_of_work" &&
+    config.gatekeeper !== "user_token"
+  ) {
     throw new Error(
-      "`proxy_key` gatekeeper mode requires a `PROXY_KEY` to be set."
+      "Captcha mode 'proof_of_work' requires gatekeeper mode 'user_token'."
     );
   }
 
-  if (config.gatekeeper !== "proxy_key" && config.proxyKey) {
+  if (config.captchaMode === "proof_of_work") {
+    const val = config.powDifficultyLevel;
+    const isDifficulty =
+      typeof val === "string" &&
+      ["low", "medium", "high", "extreme"].includes(val);
+    const isIterations =
+      typeof val === "number" && Number.isInteger(val) && val > 0;
+    if (!isDifficulty && !isIterations) {
+      throw new Error(
+        "Invalid POW_DIFFICULTY_LEVEL. Must be one of: low, medium, high, extreme, or a positive integer."
+      );
+    }
+  }
+
+  if (config.gatekeeper === "proxy_key" && !config.proxyKey) {
     throw new Error(
-      "`PROXY_KEY` is set, but gatekeeper mode is not `proxy_key`. Make sure to set `GATEKEEPER=proxy_key`."
+      "`proxy_key` gatekeeper mode requires a `PROXY_KEY` to be set."
     );
   }
 
@@ -347,6 +644,16 @@ export async function assertConfigIsValid() {
     );
   }
 
+  if (Object.values(config.httpAgent || {}).filter(Boolean).length === 0) {
+    delete config.httpAgent;
+  } else if (config.httpAgent) {
+    if (config.httpAgent.interface && config.httpAgent.proxyUrl) {
+      throw new Error(
+        "Cannot set both `HTTP_AGENT_INTERFACE` and `HTTP_AGENT_PROXY_URL`."
+      );
+    }
+  }
+
   // Ensure forks which add new secret-like config keys don't unwittingly expose
   // them to users.
   for (const key of getKeys(config)) {
@@ -360,15 +667,16 @@ export async function assertConfigIsValid() {
         `Config key "${key}" may be sensitive but is exposed. Add it to SENSITIVE_KEYS or OMITTED_KEYS.`
       );
   }
-
-  await maybeInitializeFirebase();
 }
 
 /**
  * Config keys that are masked on the info page, but not hidden as their
  * presence may be relevant to the user due to privacy implications.
  */
-export const SENSITIVE_KEYS: (keyof Config)[] = ["googleSheetsSpreadsheetId"];
+export const SENSITIVE_KEYS: (keyof Config)[] = [
+  "googleSheetsSpreadsheetId",
+  "httpAgent",
+];
 
 /**
  * Config keys that are not displayed on the info page at all, generally because
@@ -376,20 +684,28 @@ export const SENSITIVE_KEYS: (keyof Config)[] = ["googleSheetsSpreadsheetId"];
  */
 export const OMITTED_KEYS = [
   "port",
+  "bindAddress",
   "logLevel",
   "openaiKey",
   "anthropicKey",
   "googleAIKey",
   "mistralAIKey",
   "awsCredentials",
+  "gcpCredentials",
   "azureCredentials",
   "proxyKey",
   "adminKey",
+  "serviceInfoPassword",
   "rejectPhrases",
+  "rejectMessage",
   "showTokenCosts",
+  "promptLoggingFilePrefix",
   "googleSheetsKey",
   "firebaseKey",
   "firebaseRtdbUrl",
+  "sqliteDataPath",
+  "eventLogging",
+  "eventLoggingTrim",
   "gatekeeperStore",
   "maxIpsPerUser",
   "blockedOrigins",
@@ -401,6 +717,11 @@ export const OMITTED_KEYS = [
   "staticServiceInfo",
   "checkKeys",
   "allowedModelFamilies",
+  "trustedProxies",
+  "proxyEndpointRoute",
+  "adminWhitelist",
+  "ipBlacklist",
+  "powTokenPurgeHours",
 ] satisfies (keyof Config)[];
 type OmitKeys = (typeof OMITTED_KEYS)[number];
 
@@ -461,6 +782,7 @@ function getEnvWithDefault<T>(env: string | string[], defaultValue: T): T {
         "ANTHROPIC_KEY",
         "GOOGLE_AI_KEY",
         "AWS_CREDENTIALS",
+        "GCP_CREDENTIALS",
         "AZURE_CREDENTIALS",
       ].includes(String(env))
     ) {
@@ -478,32 +800,6 @@ function getEnvWithDefault<T>(env: string | string[], defaultValue: T): T {
   }
 }
 
-let firebaseApp: firebase.app.App | undefined;
-
-async function maybeInitializeFirebase() {
-  if (!config.gatekeeperStore.startsWith("firebase")) {
-    return;
-  }
-
-  const firebase = await import("firebase-admin");
-  const firebaseKey = Buffer.from(config.firebaseKey!, "base64").toString();
-  const app = firebase.initializeApp({
-    credential: firebase.credential.cert(JSON.parse(firebaseKey)),
-    databaseURL: config.firebaseRtdbUrl,
-  });
-
-  await app.database().ref("connection-test").set(Date.now());
-
-  firebaseApp = app;
-}
-
-export function getFirebaseApp(): firebase.app.App {
-  if (!firebaseApp) {
-    throw new Error("Firebase app not initialized.");
-  }
-  return firebaseApp;
-}
-
 function parseCsv(val: string): string[] {
   if (!val) return [];
 
@@ -511,3 +807,9 @@ function parseCsv(val: string): string[] {
   const matches = val.match(regex) || [];
   return matches.map((item) => item.replace(/^"|"$/g, "").trim());
 }
+
+function getDefaultModelFamilies(): ModelFamily[] {
+  return MODEL_FAMILIES.filter(
+    (f) => !f.includes("dall-e") && !f.includes("o1")
+  ) as ModelFamily[];
+}

src/info-page.ts

@@ -1,35 +1,55 @@
 /** This whole module kinda sucks */
 import fs from "fs";
-import { Request, Response } from "express";
+import express, { Router, Request, Response } from "express";
 import showdown from "showdown";
 import { config } from "./config";
 import { buildInfo, ServiceInfo } from "./service-info";
 import { getLastNImages } from "./shared/file-storage/image-history";
 import { keyPool } from "./shared/key-management";
 import { MODEL_FAMILY_SERVICE, ModelFamily } from "./shared/models";
+import { withSession } from "./shared/with-session";
+import { checkCsrfToken, injectCsrfToken } from "./shared/inject-csrf";
 
 const INFO_PAGE_TTL = 2000;
 const MODEL_FAMILY_FRIENDLY_NAME: { [f in ModelFamily]: string } = {
-  "turbo": "GPT-3.5 Turbo",
-  "gpt4": "GPT-4",
+  turbo: "GPT-4o Mini / 3.5 Turbo",
+  gpt4: "GPT-4",
   "gpt4-32k": "GPT-4 32k",
   "gpt4-turbo": "GPT-4 Turbo",
+  gpt4o: "GPT-4o",
+  o1: "OpenAI o1",
+  "o1-mini": "OpenAI o1 mini",
   "dall-e": "DALL-E",
-  "claude": "Claude",
+  claude: "Claude (Sonnet)",
+  "claude-opus": "Claude (Opus)",
+  "gemini-flash": "Gemini Flash",
   "gemini-pro": "Gemini Pro",
+  "gemini-ultra": "Gemini Ultra",
   "mistral-tiny": "Mistral 7B",
-  "mistral-small": "Mixtral 8x7B",
-  "mistral-medium": "Mistral Medium (prototype)",
-  "aws-claude": "AWS Claude",
+  "mistral-small": "Mistral Nemo",
+  "mistral-medium": "Mistral Medium",
+  "mistral-large": "Mistral Large",
+  "aws-claude": "AWS Claude (Sonnet)",
+  "aws-claude-opus": "AWS Claude (Opus)",
+  "aws-mistral-tiny": "AWS Mistral 7B",
+  "aws-mistral-small": "AWS Mistral Nemo",
+  "aws-mistral-medium": "AWS Mistral Medium",
+  "aws-mistral-large": "AWS Mistral Large",
+  "gcp-claude": "GCP Claude (Sonnet)",
+  "gcp-claude-opus": "GCP Claude (Opus)",
   "azure-turbo": "Azure GPT-3.5 Turbo",
   "azure-gpt4": "Azure GPT-4",
   "azure-gpt4-32k": "Azure GPT-4 32k",
   "azure-gpt4-turbo": "Azure GPT-4 Turbo",
+  "azure-gpt4o": "Azure GPT-4o",
+  "azure-o1": "Azure o1",
+  "azure-o1-mini": "Azure o1 mini",
+  "azure-dall-e": "Azure DALL-E",
 };
 
 const converter = new showdown.Converter();
 const customGreeting = fs.existsSync("greeting.md")
-  ? `\n## Server Greeting\n${fs.readFileSync("greeting.md", "utf8")}`
+  ? `<div id="servergreeting">${fs.readFileSync("greeting.md", "utf8")}</div>`
   : "";
 let infoPageHtml: string | undefined;
 let infoPageLastUpdated = 0;
@@ -44,7 +64,7 @@ export const handleInfoPage = (req: Request, res: Response) => {
       ? getExternalUrlForHuggingfaceSpaceId(process.env.SPACE_ID)
       : req.protocol + "://" + req.get("host");
 
-  const info = buildInfo(baseUrl + "/proxy");
+  const info = buildInfo(baseUrl + config.proxyEndpointRoute);
   infoPageHtml = renderPage(info);
   infoPageLastUpdated = Date.now();
 
@@ -55,19 +75,42 @@ export function renderPage(info: ServiceInfo) {
   const title = getServerTitle();
   const headerHtml = buildInfoPageHeader(info);
 
-  return `<!DOCTYPE html>
+  return `<!doctype html>
 <html lang="en">
   <head>
     <meta charset="utf-8" />
     <meta name="robots" content="noindex" />
     <title>${title}</title>
+    <link rel="stylesheet" href="/res/css/reset.css" media="screen" />
+    <link rel="stylesheet" href="/res/css/sakura.css" media="screen" />
+    <link rel="stylesheet" href="/res/css/sakura-dark.css" media="screen and (prefers-color-scheme: dark)" />
+    <style>
+      body {
+        font-family: sans-serif;
+        padding: 1em;
+        max-width: 900px;
+        margin: 0;
+      }
+      
+      .self-service-links {
+        display: flex;
+        justify-content: center;
+        margin-bottom: 1em;
+        padding: 0.5em;
+        font-size: 0.8em;
+      }
+      
+      .self-service-links a {
+        margin: 0 0.5em;
+      }
+    </style>
   </head>
-  <body style="font-family: sans-serif; background-color: #f0f0f0; padding: 1em;">
+  <body>
     ${headerHtml}
     <hr />
+    ${getSelfServiceLinks()}
     <h2>Service Info</h2>
     <pre>${JSON.stringify(info, null, 2)}</pre>
-    ${getSelfServiceLinks()}
   </body>
 </html>`;
 }
@@ -104,7 +147,9 @@ This proxy keeps full logs of all prompts and AI responses. Prompt logs are anon
 
     const wait = info[modelFamily]?.estimatedQueueTime;
     if (hasKeys && wait) {
-      waits.push(`**${MODEL_FAMILY_FRIENDLY_NAME[modelFamily] || modelFamily}**: ${wait}`);
+      waits.push(
+        `**${MODEL_FAMILY_FRIENDLY_NAME[modelFamily] || modelFamily}**: ${wait}`
+      );
     }
   }
 
@@ -119,7 +164,15 @@ This proxy keeps full logs of all prompts and AI responses. Prompt logs are anon
 
 function getSelfServiceLinks() {
   if (config.gatekeeper !== "user_token") return "";
-  return `<footer style="font-size: 0.8em;"><hr /><a target="_blank" href="/user/lookup">Check your user token info</a></footer>`;
+
+  const links = [["Check your user token", "/user/lookup"]];
+  if (config.captchaMode !== "none") {
+    links.unshift(["Request a user token", "/user/captcha"]);
+  }
+
+  return `<div class="self-service-links">${links
+    .map(([text, link]) => `<a href="${link}">${text}</a>`)
+    .join(" | ")}</div>`;
 }
 
 function getServerTitle() {
@@ -142,9 +195,10 @@ function getServerTitle() {
 }
 
 function buildRecentImageSection() {
+  const dalleModels: ModelFamily[] = ["azure-dall-e", "dall-e"];
   if (
-    !config.allowedModelFamilies.includes("dall-e") ||
-    !config.showRecentImages
+    !config.showRecentImages ||
+    dalleModels.every((f) => !config.allowedModelFamilies.includes(f))
   ) {
     return "";
   }
@@ -165,6 +219,7 @@ function buildRecentImageSection() {
 </div>`;
   }
   html += `</div>`;
+  html += `<p style="clear: both; text-align: center;"><a href="/user/image-history">View all recent images</a></p>`;
 
   return html;
 }
@@ -175,7 +230,9 @@ function escapeHtml(unsafe: string) {
     .replace(/</g, "&lt;")
     .replace(/>/g, "&gt;")
     .replace(/"/g, "&quot;")
-    .replace(/'/g, "&#39;");
+    .replace(/'/g, "&#39;")
+    .replace(/\[/g, "&#91;")
+    .replace(/]/g, "&#93;");
 }
 
 function getExternalUrlForHuggingfaceSpaceId(spaceId: string) {
@@ -186,3 +243,49 @@ function getExternalUrlForHuggingfaceSpaceId(spaceId: string) {
     return "";
   }
 }
+
+function checkIfUnlocked(
+  req: Request,
+  res: Response,
+  next: express.NextFunction
+) {
+  if (config.serviceInfoPassword?.length && !req.session?.unlocked) {
+    return res.redirect("/unlock-info");
+  }
+  next();
+}
+
+const infoPageRouter = Router();
+if (config.serviceInfoPassword?.length) {
+  infoPageRouter.use(
+    express.json({ limit: "1mb" }),
+    express.urlencoded({ extended: true, limit: "1mb" })
+  );
+  infoPageRouter.use(withSession);
+  infoPageRouter.use(injectCsrfToken, checkCsrfToken);
+  infoPageRouter.post("/unlock-info", (req, res) => {
+    if (req.body.password !== config.serviceInfoPassword) {
+      return res.status(403).send("Incorrect password");
+    }
+    req.session!.unlocked = true;
+    res.redirect("/");
+  });
+  infoPageRouter.get("/unlock-info", (_req, res) => {
+    if (_req.session?.unlocked) return res.redirect("/");
+
+    res.send(`
+      <form method="post" action="/unlock-info">
+        <h1>Unlock Service Info</h1>
+        <input type="hidden" name="_csrf" value="${res.locals.csrfToken}" />
+        <input type="password" name="password" placeholder="Password" />
+        <button type="submit">Unlock</button>
+      </form>
+    `);
+  });
+  infoPageRouter.use(checkIfUnlocked);
+}
+infoPageRouter.get("/", handleInfoPage);
+infoPageRouter.get("/status", (req, res) => {
+  res.json(buildInfo(req.protocol + "://" + req.get("host"), false));
+});
+export { infoPageRouter };

src/proxy/add-v1.ts

@@ -0,0 +1,9 @@
+import { NextFunction, Request, Response } from "express";
+
+export function addV1(req: Request, res: Response, next: NextFunction) {
+  // Clients don't consistently use the /v1 prefix so we'll add it for them.
+  if (!req.path.startsWith("/v1/") && !req.path.startsWith("/v1beta/")) {
+    req.url = `/v1${req.url}`;
+  }
+  next();
+}

src/proxy/anthropic.ts

@@ -1,21 +1,14 @@
 import { Request, RequestHandler, Router } from "express";
-import { createProxyMiddleware } from "http-proxy-middleware";
 import { config } from "../config";
-import { logger } from "../logger";
-import { createQueueMiddleware } from "./queue";
 import { ipLimiter } from "./rate-limit";
-import { handleProxyError } from "./middleware/common";
 import {
   addKey,
-  addAnthropicPreamble,
   createPreprocessorMiddleware,
   finalizeBody,
-  createOnProxyReqHandler,
 } from "./middleware/request";
-import {
-  ProxyResHandlerWithBody,
-  createOnProxyResHandler,
-} from "./middleware/response";
+import { ProxyResHandlerWithBody } from "./middleware/response";
+import { createQueuedProxyMiddleware } from "./middleware/request/proxy-middleware-factory";
+import { ProxyReqManager } from "./middleware/request/proxy-req-manager";
 
 let modelsCache: any = null;
 let modelsCacheTime = 0;
@@ -42,6 +35,14 @@ const getModelsResponse = () => {
     "claude-2",
     "claude-2.0",
     "claude-2.1",
+    "claude-3-haiku-20240307",
+    "claude-3-5-haiku-20241022",
+    "claude-3-opus-20240229",
+    "claude-3-opus-latest",
+    "claude-3-sonnet-20240229",
+    "claude-3-5-sonnet-20240620",
+    "claude-3-5-sonnet-20241022",
+    "claude-3-5-sonnet-latest",
   ];
 
   const models = claudeVariants.map((id) => ({
@@ -64,8 +65,7 @@ const handleModelRequest: RequestHandler = (_req, res) => {
   res.status(200).json(getModelsResponse());
 };
 
-/** Only used for non-streaming requests. */
-const anthropicResponseHandler: ProxyResHandlerWithBody = async (
+const anthropicBlockingResponseHandler: ProxyResHandlerWithBody = async (
   _proxyRes,
   req,
   res,
@@ -75,30 +75,50 @@ const anthropicResponseHandler: ProxyResHandlerWithBody = async (
     throw new Error("Expected body to be an object");
   }
 
-  if (config.promptLogging) {
-    const host = req.get("host");
-    body.proxy_note = `Prompts are logged on this proxy instance. See ${host} for more information.`;
+  let newBody = body;
+  switch (`${req.inboundApi}<-${req.outboundApi}`) {
+    case "openai<-anthropic-text":
+      req.log.info("Transforming Anthropic Text back to OpenAI format");
+      newBody = transformAnthropicTextResponseToOpenAI(body, req);
+      break;
+    case "openai<-anthropic-chat":
+      req.log.info("Transforming Anthropic Chat back to OpenAI format");
+      newBody = transformAnthropicChatResponseToOpenAI(body);
+      break;
+    case "anthropic-text<-anthropic-chat":
+      req.log.info("Transforming Anthropic Chat back to Anthropic chat format");
+      newBody = transformAnthropicChatResponseToAnthropicText(body);
+      break;
   }
 
-  if (req.inboundApi === "openai") {
-    req.log.info("Transforming Anthropic response to OpenAI format");
-    body = transformAnthropicResponse(body, req);
-  }
-
-  if (req.tokenizerInfo) {
-    body.proxy_tokenizer = req.tokenizerInfo;
-  }
-
-  res.status(200).json(body);
+  res.status(200).json({ ...newBody, proxy: body.proxy });
 };
 
-/**
- * Transforms a model response from the Anthropic API to match those from the
- * OpenAI API, for users using Claude via the OpenAI-compatible endpoint. This
- * is only used for non-streaming requests as streaming requests are handled
- * on-the-fly.
- */
-function transformAnthropicResponse(
+function flattenChatResponse(
+  content: { type: string; text: string }[]
+): string {
+  return content
+    .map((part: { type: string; text: string }) =>
+      part.type === "text" ? part.text : ""
+    )
+    .join("\n");
+}
+
+export function transformAnthropicChatResponseToAnthropicText(
+  anthropicBody: Record<string, any>
+): Record<string, any> {
+  return {
+    type: "completion",
+    id: "ant-" + anthropicBody.id,
+    completion: flattenChatResponse(anthropicBody.content),
+    stop_reason: anthropicBody.stop_reason,
+    stop: anthropicBody.stop_sequence,
+    model: anthropicBody.model,
+    usage: anthropicBody.usage,
+  };
+}
+
+function transformAnthropicTextResponseToOpenAI(
   anthropicBody: Record<string, any>,
   req: Request
 ): Record<string, any> {
@@ -126,63 +146,155 @@ function transformAnthropicResponse(
   };
 }
 
-const anthropicProxy = createQueueMiddleware({
-  proxyMiddleware: createProxyMiddleware({
-    target: "https://api.anthropic.com",
-    changeOrigin: true,
-    selfHandleResponse: true,
-    logger,
-    on: {
-      proxyReq: createOnProxyReqHandler({
-        pipeline: [addKey, addAnthropicPreamble, finalizeBody],
-      }),
-      proxyRes: createOnProxyResHandler([anthropicResponseHandler]),
-      error: handleProxyError,
-    },
-    pathRewrite: {
-      // Send OpenAI-compat requests to the real Anthropic endpoint.
-      "^/v1/chat/completions": "/v1/complete",
-    },
-  }),
+export function transformAnthropicChatResponseToOpenAI(
+  anthropicBody: Record<string, any>
+): Record<string, any> {
+  return {
+    id: "ant-" + anthropicBody.id,
+    object: "chat.completion",
+    created: Date.now(),
+    model: anthropicBody.model,
+    usage: anthropicBody.usage,
+    choices: [
+      {
+        message: {
+          role: "assistant",
+          content: flattenChatResponse(anthropicBody.content),
+        },
+        finish_reason: anthropicBody.stop_reason,
+        index: 0,
+      },
+    ],
+  };
+}
+
+/**
+ * If a client using the OpenAI compatibility endpoint requests an actual OpenAI
+ * model, reassigns it to Sonnet.
+ */
+function maybeReassignModel(req: Request) {
+  const model = req.body.model;
+  if (model.includes("claude")) return; // use whatever model the user requested
+  req.body.model = "claude-3-5-sonnet-latest";
+}
+
+/**
+ * If client requests more than 4096 output tokens the request must have a
+ * particular version header.
+ * https://docs.anthropic.com/en/release-notes/api#july-15th-2024
+ */
+function setAnthropicBetaHeader(req: Request) {
+  const { max_tokens_to_sample } = req.body;
+  if (max_tokens_to_sample > 4096) {
+    req.headers["anthropic-beta"] = "max-tokens-3-5-sonnet-2024-07-15";
+  }
+}
+
+function selectUpstreamPath(manager: ProxyReqManager) {
+  const req = manager.request;
+  const pathname = req.url.split("?")[0];
+  req.log.debug({ pathname }, "Anthropic path filter");
+  const isText = req.outboundApi === "anthropic-text";
+  const isChat = req.outboundApi === "anthropic-chat";
+  if (isChat && pathname === "/v1/complete") {
+    manager.setPath("/v1/messages");
+  }
+  if (isText && pathname === "/v1/chat/completions") {
+    manager.setPath("/v1/complete");
+  }
+  if (isChat && pathname === "/v1/chat/completions") {
+    manager.setPath("/v1/messages");
+  }
+  if (isChat && ["sonnet", "opus"].includes(req.params.type)) {
+    manager.setPath("/v1/messages");
+  }
+}
+
+const anthropicProxy = createQueuedProxyMiddleware({
+  target: "https://api.anthropic.com",
+  mutations: [selectUpstreamPath, addKey, finalizeBody],
+  blockingResponseHandler: anthropicBlockingResponseHandler,
 });
 
+const nativeAnthropicChatPreprocessor = createPreprocessorMiddleware(
+  { inApi: "anthropic-chat", outApi: "anthropic-chat", service: "anthropic" },
+  { afterTransform: [setAnthropicBetaHeader] }
+);
+
+const nativeTextPreprocessor = createPreprocessorMiddleware({
+  inApi: "anthropic-text",
+  outApi: "anthropic-text",
+  service: "anthropic",
+});
+
+const textToChatPreprocessor = createPreprocessorMiddleware({
+  inApi: "anthropic-text",
+  outApi: "anthropic-chat",
+  service: "anthropic",
+});
+
+/**
+ * Routes text completion prompts to anthropic-chat if they need translation
+ * (claude-3 based models do not support the old text completion endpoint).
+ */
+const preprocessAnthropicTextRequest: RequestHandler = (req, res, next) => {
+  if (req.body.model?.startsWith("claude-3")) {
+    textToChatPreprocessor(req, res, next);
+  } else {
+    nativeTextPreprocessor(req, res, next);
+  }
+};
+
+const oaiToTextPreprocessor = createPreprocessorMiddleware({
+  inApi: "openai",
+  outApi: "anthropic-text",
+  service: "anthropic",
+});
+
+const oaiToChatPreprocessor = createPreprocessorMiddleware({
+  inApi: "openai",
+  outApi: "anthropic-chat",
+  service: "anthropic",
+});
+
+/**
+ * Routes an OpenAI prompt to either the legacy Claude text completion endpoint
+ * or the new Claude chat completion endpoint, based on the requested model.
+ */
+const preprocessOpenAICompatRequest: RequestHandler = (req, res, next) => {
+  maybeReassignModel(req);
+  if (req.body.model?.includes("claude-3")) {
+    oaiToChatPreprocessor(req, res, next);
+  } else {
+    oaiToTextPreprocessor(req, res, next);
+  }
+};
+
 const anthropicRouter = Router();
 anthropicRouter.get("/v1/models", handleModelRequest);
 // Native Anthropic chat completion endpoint.
 anthropicRouter.post(
-  "/v1/complete",
+  "/v1/messages",
   ipLimiter,
-  createPreprocessorMiddleware({
-    inApi: "anthropic",
-    outApi: "anthropic",
-    service: "anthropic",
-  }),
+  nativeAnthropicChatPreprocessor,
   anthropicProxy
 );
-// OpenAI-to-Anthropic compatibility endpoint.
+// Anthropic text completion endpoint. Translates to Anthropic chat completion
+// if the requested model is a Claude 3 model.
+anthropicRouter.post(
+  "/v1/complete",
+  ipLimiter,
+  preprocessAnthropicTextRequest,
+  anthropicProxy
+);
+// OpenAI-to-Anthropic compatibility endpoint. Accepts an OpenAI chat completion
+// request and transforms/routes it to the appropriate Anthropic format and
+// endpoint based on the requested model.
 anthropicRouter.post(
   "/v1/chat/completions",
   ipLimiter,
-  createPreprocessorMiddleware(
-    { inApi: "openai", outApi: "anthropic", service: "anthropic" },
-    { afterTransform: [maybeReassignModel] }
-  ),
+  preprocessOpenAICompatRequest,
   anthropicProxy
 );
 
-function maybeReassignModel(req: Request) {
-  const model = req.body.model;
-  if (!model.startsWith("gpt-")) return;
-
-  const bigModel = process.env.CLAUDE_BIG_MODEL || "claude-v1-100k";
-  const contextSize = req.promptTokens! + req.outputTokens!;
-  if (contextSize > 8500) {
-    req.log.debug(
-      { model: bigModel, contextSize },
-      "Using Claude 100k model for OpenAI-to-Anthropic request"
-    );
-    req.body.model = bigModel;
-  }
-}
-
 export const anthropic = anthropicRouter;

src/proxy/aws-claude.ts

@@ -0,0 +1,257 @@
+import { Request, RequestHandler, Router } from "express";
+import { v4 } from "uuid";
+import {
+  transformAnthropicChatResponseToAnthropicText,
+  transformAnthropicChatResponseToOpenAI,
+} from "./anthropic";
+import { ipLimiter } from "./rate-limit";
+import {
+  createPreprocessorMiddleware,
+  finalizeSignedRequest,
+  signAwsRequest,
+} from "./middleware/request";
+import { ProxyResHandlerWithBody } from "./middleware/response";
+import { createQueuedProxyMiddleware } from "./middleware/request/proxy-middleware-factory";
+
+const awsBlockingResponseHandler: ProxyResHandlerWithBody = async (
+  _proxyRes,
+  req,
+  res,
+  body
+) => {
+  if (typeof body !== "object") {
+    throw new Error("Expected body to be an object");
+  }
+
+  let newBody = body;
+  switch (`${req.inboundApi}<-${req.outboundApi}`) {
+    case "openai<-anthropic-text":
+      req.log.info("Transforming Anthropic Text back to OpenAI format");
+      newBody = transformAwsTextResponseToOpenAI(body, req);
+      break;
+    case "openai<-anthropic-chat":
+      req.log.info("Transforming AWS Anthropic Chat back to OpenAI format");
+      newBody = transformAnthropicChatResponseToOpenAI(body);
+      break;
+    case "anthropic-text<-anthropic-chat":
+      req.log.info("Transforming AWS Anthropic Chat back to Text format");
+      newBody = transformAnthropicChatResponseToAnthropicText(body);
+      break;
+  }
+
+  // AWS does not always confirm the model in the response, so we have to add it
+  if (!newBody.model && req.body.model) {
+    newBody.model = req.body.model;
+  }
+
+  res.status(200).json({ ...newBody, proxy: body.proxy });
+};
+
+function transformAwsTextResponseToOpenAI(
+  awsBody: Record<string, any>,
+  req: Request
+): Record<string, any> {
+  const totalTokens = (req.promptTokens ?? 0) + (req.outputTokens ?? 0);
+  return {
+    id: "aws-" + v4(),
+    object: "chat.completion",
+    created: Date.now(),
+    model: req.body.model,
+    usage: {
+      prompt_tokens: req.promptTokens,
+      completion_tokens: req.outputTokens,
+      total_tokens: totalTokens,
+    },
+    choices: [
+      {
+        message: {
+          role: "assistant",
+          content: awsBody.completion?.trim(),
+        },
+        finish_reason: awsBody.stop_reason,
+        index: 0,
+      },
+    ],
+  };
+}
+
+const awsClaudeProxy = createQueuedProxyMiddleware({
+  target: ({ signedRequest }) => {
+    if (!signedRequest) throw new Error("Must sign request before proxying");
+    return `${signedRequest.protocol}//${signedRequest.hostname}`;
+  },
+  mutations: [signAwsRequest, finalizeSignedRequest],
+  blockingResponseHandler: awsBlockingResponseHandler,
+});
+
+const nativeTextPreprocessor = createPreprocessorMiddleware(
+  { inApi: "anthropic-text", outApi: "anthropic-text", service: "aws" },
+  { afterTransform: [maybeReassignModel] }
+);
+
+const textToChatPreprocessor = createPreprocessorMiddleware(
+  { inApi: "anthropic-text", outApi: "anthropic-chat", service: "aws" },
+  { afterTransform: [maybeReassignModel] }
+);
+
+/**
+ * Routes text completion prompts to aws anthropic-chat if they need translation
+ * (claude-3 based models do not support the old text completion endpoint).
+ */
+const preprocessAwsTextRequest: RequestHandler = (req, res, next) => {
+  if (req.body.model?.includes("claude-3")) {
+    textToChatPreprocessor(req, res, next);
+  } else {
+    nativeTextPreprocessor(req, res, next);
+  }
+};
+
+const oaiToAwsTextPreprocessor = createPreprocessorMiddleware(
+  { inApi: "openai", outApi: "anthropic-text", service: "aws" },
+  { afterTransform: [maybeReassignModel] }
+);
+
+const oaiToAwsChatPreprocessor = createPreprocessorMiddleware(
+  { inApi: "openai", outApi: "anthropic-chat", service: "aws" },
+  { afterTransform: [maybeReassignModel] }
+);
+
+/**
+ * Routes an OpenAI prompt to either the legacy Claude text completion endpoint
+ * or the new Claude chat completion endpoint, based on the requested model.
+ */
+const preprocessOpenAICompatRequest: RequestHandler = (req, res, next) => {
+  if (req.body.model?.includes("claude-3")) {
+    oaiToAwsChatPreprocessor(req, res, next);
+  } else {
+    oaiToAwsTextPreprocessor(req, res, next);
+  }
+};
+
+const awsClaudeRouter = Router();
+// Native(ish) Anthropic text completion endpoint.
+awsClaudeRouter.post(
+  "/v1/complete",
+  ipLimiter,
+  preprocessAwsTextRequest,
+  awsClaudeProxy
+);
+// Native Anthropic chat completion endpoint.
+awsClaudeRouter.post(
+  "/v1/messages",
+  ipLimiter,
+  createPreprocessorMiddleware(
+    { inApi: "anthropic-chat", outApi: "anthropic-chat", service: "aws" },
+    { afterTransform: [maybeReassignModel] }
+  ),
+  awsClaudeProxy
+);
+
+// OpenAI-to-AWS Anthropic compatibility endpoint.
+awsClaudeRouter.post(
+  "/v1/chat/completions",
+  ipLimiter,
+  preprocessOpenAICompatRequest,
+  awsClaudeProxy
+);
+
+/**
+ * Tries to deal with:
+ * - frontends sending AWS model names even when they want to use the OpenAI-
+ *   compatible endpoint
+ * - frontends sending Anthropic model names that AWS doesn't recognize
+ * - frontends sending OpenAI model names because they expect the proxy to
+ *   translate them
+ *
+ * If client sends AWS model ID it will be used verbatim. Otherwise, various
+ * strategies are used to try to map a non-AWS model name to AWS model ID.
+ */
+function maybeReassignModel(req: Request) {
+  const model = req.body.model;
+
+  // If it looks like an AWS model, use it as-is
+  if (model.includes("anthropic.claude")) {
+    return;
+  }
+
+  // Anthropic model names can look like:
+  // - claude-v1
+  // - claude-2.1
+  // - claude-3-5-sonnet-20240620
+  // - claude-3-opus-latest
+  const pattern =
+    /^(claude-)?(instant-)?(v)?(\d+)([.-](\d))?(-\d+k)?(-sonnet-|-opus-|-haiku-)?(latest|\d*)/i;
+  const match = model.match(pattern);
+
+  if (!match) {
+    throw new Error(`Provided model name (${model}) doesn't resemble a Claude model ID.`);
+  }
+
+  const [_, _cl, instant, _v, major, _sep, minor, _ctx, rawName, rev] = match;
+
+  if (instant) {
+    req.body.model = "anthropic.claude-instant-v1";
+    return;
+  }
+
+  const ver = minor ? `${major}.${minor}` : major;
+  const name = rawName?.match(/([a-z]+)/)?.[1] || "";
+
+  switch (ver) {
+    case "1":
+    case "1.0":
+      req.body.model = "anthropic.claude-v1";
+      return;
+    case "2":
+    case "2.0":
+      req.body.model = "anthropic.claude-v2";
+      return;
+    case "2.1":
+      req.body.model = "anthropic.claude-v2:1";
+      return;
+    case "3":
+    case "3.0":
+      // there is only one snapshot for all Claude 3 models so there is no need
+      // to check the revision
+      switch (name) {
+        case "sonnet":
+          req.body.model = "anthropic.claude-3-sonnet-20240229-v1:0";
+          return;
+        case "haiku":
+          req.body.model = "anthropic.claude-3-haiku-20240307-v1:0";
+          return;
+        case "opus":
+          req.body.model = "anthropic.claude-3-opus-20240229-v1:0";
+          return;
+      }
+      break;
+    case "3.5":
+      switch (name) {
+        case "sonnet":
+          switch (rev) {
+            case "20241022":
+            case "latest":
+              req.body.model = "anthropic.claude-3-5-sonnet-20241022-v2:0";
+              return;
+            case "20240620":
+              req.body.model = "anthropic.claude-3-5-sonnet-20240620-v1:0";
+              return;
+          }
+          break;
+        case "haiku":
+          switch (rev) {
+            case "20241022":
+            case "latest":
+              req.body.model = "anthropic.claude-3-5-haiku-20241022-v1:0";
+              return;
+          }
+        case "opus":
+          // Add after model id is announced never
+          break;
+      }
+  }
+
+  throw new Error(`Provided model name (${model}) could not be mapped to a known AWS Claude model ID.`);
+}
+
+export const awsClaude = awsClaudeRouter;

src/proxy/aws-mistral.ts

@@ -0,0 +1,95 @@
+import { Request, Router } from "express";
+import {
+  detectMistralInputApi,
+  transformMistralTextToMistralChat,
+} from "./mistral-ai";
+import { ipLimiter } from "./rate-limit";
+import { ProxyResHandlerWithBody } from "./middleware/response";
+import {
+  createPreprocessorMiddleware,
+  finalizeSignedRequest,
+  signAwsRequest,
+} from "./middleware/request";
+import { createQueuedProxyMiddleware } from "./middleware/request/proxy-middleware-factory";
+
+const awsMistralBlockingResponseHandler: ProxyResHandlerWithBody = async (
+  _proxyRes,
+  req,
+  res,
+  body
+) => {
+  if (typeof body !== "object") {
+    throw new Error("Expected body to be an object");
+  }
+
+  let newBody = body;
+  if (req.inboundApi === "mistral-ai" && req.outboundApi === "mistral-text") {
+    newBody = transformMistralTextToMistralChat(body);
+  }
+  // AWS does not always confirm the model in the response, so we have to add it
+  if (!newBody.model && req.body.model) {
+    newBody.model = req.body.model;
+  }
+
+  res.status(200).json({ ...newBody, proxy: body.proxy });
+};
+
+const awsMistralProxy = createQueuedProxyMiddleware({
+  target: ({ signedRequest }) => {
+    if (!signedRequest) throw new Error("Must sign request before proxying");
+    return `${signedRequest.protocol}//${signedRequest.hostname}`;
+  },
+  mutations: [signAwsRequest,finalizeSignedRequest],
+  blockingResponseHandler: awsMistralBlockingResponseHandler,
+});
+
+function maybeReassignModel(req: Request) {
+  const model = req.body.model;
+
+  // If it looks like an AWS model, use it as-is
+  if (model.startsWith("mistral.")) {
+    return;
+  }
+  // Mistral 7B Instruct
+  else if (model.includes("7b")) {
+    req.body.model = "mistral.mistral-7b-instruct-v0:2";
+  }
+  // Mistral 8x7B Instruct
+  else if (model.includes("8x7b")) {
+    req.body.model = "mistral.mixtral-8x7b-instruct-v0:1";
+  }
+  // Mistral Large (Feb 2024)
+  else if (model.includes("large-2402")) {
+    req.body.model = "mistral.mistral-large-2402-v1:0";
+  }
+  // Mistral Large 2 (July 2024)
+  else if (model.includes("large")) {
+    req.body.model = "mistral.mistral-large-2407-v1:0";
+  }
+  // Mistral Small (Feb 2024)
+  else if (model.includes("small")) {
+    req.body.model = "mistral.mistral-small-2402-v1:0";
+  } else {
+    throw new Error(
+      `Can't map '${model}' to a supported AWS model ID; make sure you are requesting a Mistral model supported by Amazon Bedrock`
+    );
+  }
+}
+
+const nativeMistralChatPreprocessor = createPreprocessorMiddleware(
+  { inApi: "mistral-ai", outApi: "mistral-ai", service: "aws" },
+  {
+    beforeTransform: [detectMistralInputApi],
+    afterTransform: [maybeReassignModel],
+  }
+);
+
+const awsMistralRouter = Router();
+awsMistralRouter.post(
+  "/v1/chat/completions",
+  ipLimiter,
+  nativeMistralChatPreprocessor,
+  awsMistralProxy
+);
+
+export const awsMistral = awsMistralRouter;

src/proxy/aws.ts

@@ -1,218 +1,77 @@
-import { Request, RequestHandler, Router } from "express";
-import { createProxyMiddleware } from "http-proxy-middleware";
-import { v4 } from "uuid";
+/* Shared code between AWS Claude and AWS Mistral endpoints. */
+
+import { Request, Response, Router } from "express";
 import { config } from "../config";
-import { logger } from "../logger";
-import { createQueueMiddleware } from "./queue";
-import { ipLimiter } from "./rate-limit";
-import { handleProxyError } from "./middleware/common";
-import {
-  createPreprocessorMiddleware,
-  signAwsRequest,
-  finalizeSignedRequest,
-  createOnProxyReqHandler,
-} from "./middleware/request";
-import {
-  ProxyResHandlerWithBody,
-  createOnProxyResHandler,
-} from "./middleware/response";
-
-const LATEST_AWS_V2_MINOR_VERSION = "1";
-
-let modelsCache: any = null;
-let modelsCacheTime = 0;
-
-const getModelsResponse = () => {
-  if (new Date().getTime() - modelsCacheTime < 1000 * 60) {
-    return modelsCache;
-  }
-
-  if (!config.awsCredentials) return { object: "list", data: [] };
-
-  const variants = [
-    "anthropic.claude-v1",
-    "anthropic.claude-v2",
-    "anthropic.claude-v2:1",
-  ];
-
-  const models = variants.map((id) => ({
-    id,
-    object: "model",
-    created: new Date().getTime(),
-    owned_by: "anthropic",
-    permission: [],
-    root: "claude",
-    parent: null,
-  }));
-
-  modelsCache = { object: "list", data: models };
-  modelsCacheTime = new Date().getTime();
-
-  return modelsCache;
-};
-
-const handleModelRequest: RequestHandler = (_req, res) => {
-  res.status(200).json(getModelsResponse());
-};
-
-/** Only used for non-streaming requests. */
-const awsResponseHandler: ProxyResHandlerWithBody = async (
-  _proxyRes,
-  req,
-  res,
-  body
-) => {
-  if (typeof body !== "object") {
-    throw new Error("Expected body to be an object");
-  }
-
-  if (config.promptLogging) {
-    const host = req.get("host");
-    body.proxy_note = `Prompts are logged on this proxy instance. See ${host} for more information.`;
-  }
-
-  if (req.inboundApi === "openai") {
-    req.log.info("Transforming AWS Claude response to OpenAI format");
-    body = transformAwsResponse(body, req);
-  }
-
-  if (req.tokenizerInfo) {
-    body.proxy_tokenizer = req.tokenizerInfo;
-  }
-
-  // AWS does not confirm the model in the response, so we have to add it
-  body.model = req.body.model;
-
-  res.status(200).json(body);
-};
-
-/**
- * Transforms a model response from the Anthropic API to match those from the
- * OpenAI API, for users using Claude via the OpenAI-compatible endpoint. This
- * is only used for non-streaming requests as streaming requests are handled
- * on-the-fly.
- */
-function transformAwsResponse(
-  awsBody: Record<string, any>,
-  req: Request
-): Record<string, any> {
-  const totalTokens = (req.promptTokens ?? 0) + (req.outputTokens ?? 0);
-  return {
-    id: "aws-" + v4(),
-    object: "chat.completion",
-    created: Date.now(),
-    model: req.body.model,
-    usage: {
-      prompt_tokens: req.promptTokens,
-      completion_tokens: req.outputTokens,
-      total_tokens: totalTokens,
-    },
-    choices: [
-      {
-        message: {
-          role: "assistant",
-          content: awsBody.completion?.trim(),
-        },
-        finish_reason: awsBody.stop_reason,
-        index: 0,
-      },
-    ],
-  };
-}
-
-const awsProxy = createQueueMiddleware({
-  beforeProxy: signAwsRequest,
-  proxyMiddleware: createProxyMiddleware({
-    target: "bad-target-will-be-rewritten",
-    router: ({ signedRequest }) => {
-      if (!signedRequest) throw new Error("Must sign request before proxying");
-      return `${signedRequest.protocol}//${signedRequest.hostname}`;
-    },
-    changeOrigin: true,
-    selfHandleResponse: true,
-    logger,
-    on: {
-      proxyReq: createOnProxyReqHandler({ pipeline: [finalizeSignedRequest] }),
-      proxyRes: createOnProxyResHandler([awsResponseHandler]),
-      error: handleProxyError,
-    },
-  }),
-});
+import { addV1 } from "./add-v1";
+import { awsClaude } from "./aws-claude";
+import { awsMistral } from "./aws-mistral";
+import { AwsBedrockKey, keyPool } from "../shared/key-management";
 
 const awsRouter = Router();
-awsRouter.get("/v1/models", handleModelRequest);
-// Native(ish) Anthropic chat completion endpoint.
-awsRouter.post(
-  "/v1/complete",
-  ipLimiter,
-  createPreprocessorMiddleware(
-    { inApi: "anthropic", outApi: "anthropic", service: "aws" },
-    { afterTransform: [maybeReassignModel] }
-  ),
-  awsProxy
-);
-// OpenAI-to-AWS Anthropic compatibility endpoint.
-awsRouter.post(
-  "/v1/chat/completions",
-  ipLimiter,
-  createPreprocessorMiddleware(
-    { inApi: "openai", outApi: "anthropic", service: "aws" },
-    { afterTransform: [maybeReassignModel] }
-  ),
-  awsProxy
-);
+awsRouter.get(["/:vendor?/v1/models", "/:vendor?/models"], handleModelsRequest);
+awsRouter.use("/claude", addV1, awsClaude);
+awsRouter.use("/mistral", addV1, awsMistral);
 
-/**
- * Tries to deal with:
- * - frontends sending AWS model names even when they want to use the OpenAI-
- *   compatible endpoint
- * - frontends sending Anthropic model names that AWS doesn't recognize
- * - frontends sending OpenAI model names because they expect the proxy to
- *   translate them
- */
-function maybeReassignModel(req: Request) {
-  const model = req.body.model;
+const MODELS_CACHE_TTL = 10000;
+let modelsCache: Record<string, any> = {};
+let modelsCacheTime: Record<string, number> = {};
+function handleModelsRequest(req: Request, res: Response) {
+  if (!config.awsCredentials) return { object: "list", data: [] };
 
-  // If client already specified an AWS Claude model ID, use it
-  if (model.includes("anthropic.claude")) {
-    return;
+  const vendor = req.params.vendor?.length
+    ? req.params.vendor === "claude"
+      ? "anthropic"
+      : req.params.vendor
+    : "all";
+
+  const cacheTime = modelsCacheTime[vendor] || 0;
+  if (new Date().getTime() - cacheTime < MODELS_CACHE_TTL) {
+    return res.json(modelsCache[vendor]);
   }
 
-  const pattern = /^(claude-)?(instant-)?(v)?(\d+)(\.(\d+))?(-\d+k)?$/i;
-  const match = model.match(pattern);
-
-  // If there's no match, return the latest v2 model
-  if (!match) {
-    req.body.model = `anthropic.claude-v2:${LATEST_AWS_V2_MINOR_VERSION}`;
-    return;
+  const availableModelIds = new Set<string>();
+  for (const key of keyPool.list()) {
+    if (key.isDisabled || key.service !== "aws") continue;
+    (key as AwsBedrockKey).modelIds.forEach((id) => availableModelIds.add(id));
   }
 
-  const [, , instant, , major, , minor] = match;
+  // https://docs.aws.amazon.com/bedrock/latest/userguide/model-ids.html
+  const models = [
+    "anthropic.claude-v2",
+    "anthropic.claude-v2:1",
+    "anthropic.claude-3-haiku-20240307-v1:0",
+    "anthropic.claude-3-5-haiku-20241022-v1:0",
+    "anthropic.claude-3-sonnet-20240229-v1:0",
+    "anthropic.claude-3-5-sonnet-20240620-v1:0",
+    "anthropic.claude-3-5-sonnet-20241022-v2:0",
+    "anthropic.claude-3-opus-20240229-v1:0",
+    "mistral.mistral-7b-instruct-v0:2",
+    "mistral.mixtral-8x7b-instruct-v0:1",
+    "mistral.mistral-large-2402-v1:0",
+    "mistral.mistral-large-2407-v1:0",
+    "mistral.mistral-small-2402-v1:0",
+  ]
+    .filter((id) => availableModelIds.has(id))
+    .map((id) => {
+      const vendor = id.match(/^(.*)\./)?.[1];
+      return {
+        id,
+        object: "model",
+        created: new Date().getTime(),
+        owned_by: vendor,
+        permission: [],
+        root: vendor,
+        parent: null,
+      };
+    });
 
-  if (instant) {
-    req.body.model = "anthropic.claude-instant-v1";
-    return;
-  }
+  modelsCache[vendor] = {
+    object: "list",
+    data: models.filter((m) => vendor === "all" || m.root === vendor),
+  };
+  modelsCacheTime[vendor] = new Date().getTime();
 
-  // There's only one v1 model
-  if (major === "1") {
-    req.body.model = "anthropic.claude-v1";
-    return;
-  }
-
-  // Try to map Anthropic API v2 models to AWS v2 models
-  if (major === "2") {
-    if (minor === "0") {
-      req.body.model = "anthropic.claude-v2";
-      return;
-    }
-    req.body.model = `anthropic.claude-v2:${LATEST_AWS_V2_MINOR_VERSION}`;
-    return;
-  }
-
-  // Fallback to latest v2 model
-  req.body.model = `anthropic.claude-v2:${LATEST_AWS_V2_MINOR_VERSION}`;
-  return;
+  return res.json(modelsCache[vendor]);
 }
 
 export const aws = awsRouter;

src/proxy/azure.ts

@@ -1,73 +1,30 @@
 import { RequestHandler, Router } from "express";
-import { createProxyMiddleware } from "http-proxy-middleware";
 import { config } from "../config";
-import { keyPool } from "../shared/key-management";
-import {
-  ModelFamily,
-  AzureOpenAIModelFamily,
-  getAzureOpenAIModelFamily,
-} from "../shared/models";
-import { logger } from "../logger";
-import { KNOWN_OPENAI_MODELS } from "./openai";
-import { createQueueMiddleware } from "./queue";
+import { generateModelList } from "./openai";
 import { ipLimiter } from "./rate-limit";
-import { handleProxyError } from "./middleware/common";
 import {
   addAzureKey,
-  createOnProxyReqHandler,
   createPreprocessorMiddleware,
   finalizeSignedRequest,
 } from "./middleware/request";
-import {
-  createOnProxyResHandler,
-  ProxyResHandlerWithBody,
-} from "./middleware/response";
+import { ProxyResHandlerWithBody } from "./middleware/response";
+import { createQueuedProxyMiddleware } from "./middleware/request/proxy-middleware-factory";
 
 let modelsCache: any = null;
 let modelsCacheTime = 0;
 
-function getModelsResponse() {
-  if (new Date().getTime() - modelsCacheTime < 1000 * 60) {
-    return modelsCache;
-  }
-
-  let available = new Set<AzureOpenAIModelFamily>();
-  for (const key of keyPool.list()) {
-    if (key.isDisabled || key.service !== "azure") continue;
-    key.modelFamilies.forEach((family) =>
-      available.add(family as AzureOpenAIModelFamily)
-    );
-  }
-  const allowed = new Set<ModelFamily>(config.allowedModelFamilies);
-  available = new Set([...available].filter((x) => allowed.has(x)));
-
-  const models = KNOWN_OPENAI_MODELS.map((id) => ({
-    id,
-    object: "model",
-    created: new Date().getTime(),
-    owned_by: "azure",
-    permission: [
-      {
-        id: "modelperm-" + id,
-        object: "model_permission",
-        created: new Date().getTime(),
-        organization: "*",
-        group: null,
-        is_blocking: false,
-      },
-    ],
-    root: id,
-    parent: null,
-  })).filter((model) => available.has(getAzureOpenAIModelFamily(model.id)));
-
-  modelsCache = { object: "list", data: models };
-  modelsCacheTime = new Date().getTime();
-
-  return modelsCache;
-}
-
 const handleModelRequest: RequestHandler = (_req, res) => {
-  res.status(200).json(getModelsResponse());
+  if (new Date().getTime() - modelsCacheTime < 1000 * 60) {
+    return res.status(200).json(modelsCache);
+  }
+
+  if (!config.azureCredentials) return { object: "list", data: [] };
+
+  const result = generateModelList("azure");
+
+  modelsCache = { object: "list", data: result };
+  modelsCacheTime = new Date().getTime();
+  res.status(200).json(modelsCache);
 };
 
 const azureOpenaiResponseHandler: ProxyResHandlerWithBody = async (
@@ -80,38 +37,20 @@ const azureOpenaiResponseHandler: ProxyResHandlerWithBody = async (
     throw new Error("Expected body to be an object");
   }
 
-  if (config.promptLogging) {
-    const host = req.get("host");
-    body.proxy_note = `Prompts are logged on this proxy instance. See ${host} for more information.`;
-  }
-
-  if (req.tokenizerInfo) {
-    body.proxy_tokenizer = req.tokenizerInfo;
-  }
-
-  res.status(200).json(body);
+  res.status(200).json({ ...body, proxy: body.proxy });
 };
 
-const azureOpenAIProxy = createQueueMiddleware({
-  beforeProxy: addAzureKey,
-  proxyMiddleware: createProxyMiddleware({
-    target: "will be set by router",
-    router: (req) => {
-      if (!req.signedRequest) throw new Error("signedRequest not set");
-      const { hostname, path } = req.signedRequest;
-      return `https://${hostname}${path}`;
-    },
-    changeOrigin: true,
-    selfHandleResponse: true,
-    logger,
-    on: {
-      proxyReq: createOnProxyReqHandler({ pipeline: [finalizeSignedRequest] }),
-      proxyRes: createOnProxyResHandler([azureOpenaiResponseHandler]),
-      error: handleProxyError,
-    },
-  }),
+const azureOpenAIProxy = createQueuedProxyMiddleware({
+  target: ({ signedRequest }) => {
+    if (!signedRequest) throw new Error("Must sign request before proxying");
+    const { hostname, protocol } = signedRequest;
+    return `${protocol}//${hostname}`;
+  },
+  mutations: [addAzureKey, finalizeSignedRequest],
+  blockingResponseHandler: azureOpenaiResponseHandler,
 });
 
+
 const azureOpenAIRouter = Router();
 azureOpenAIRouter.get("/v1/models", handleModelRequest);
 azureOpenAIRouter.post(
@@ -124,5 +63,15 @@ azureOpenAIRouter.post(
   }),
   azureOpenAIProxy
 );
+azureOpenAIRouter.post(
+  "/v1/images/generations",
+  ipLimiter,
+  createPreprocessorMiddleware({
+    inApi: "openai-image",
+    outApi: "openai-image",
+    service: "azure",
+  }),
+  azureOpenAIProxy
+);
 
 export const azure = azureOpenAIRouter;

src/proxy/gatekeeper.ts

@@ -1,6 +1,7 @@
-import type { Request, RequestHandler } from "express";
+import type { Request, Response, RequestHandler } from "express";
 import { config } from "../config";
 import { authenticate, getUser } from "../shared/users/user-store";
+import { sendErrorToClient } from "./middleware/response/error-generator";
 
 const GATEKEEPER = config.gatekeeper;
 const PROXY_KEY = config.proxyKey;
@@ -11,6 +12,7 @@ function getProxyAuthorizationFromRequest(req: Request): string | undefined {
   // pass the _proxy_ key in this header too, instead of providing it as a
   // Bearer token in the Authorization header.  So we need to check both.
   // Prefer the Authorization header if both are present.
+  // Google AI uses a key querystring parameter.
 
   if (req.headers.authorization) {
     const token = req.headers.authorization?.slice("Bearer ".length);
@@ -23,6 +25,12 @@ function getProxyAuthorizationFromRequest(req: Request): string | undefined {
     delete req.headers["x-api-key"];
     return token;
   }
+  
+  if (req.query.key) {
+    const token = req.query.key?.toString();
+    delete req.query.key;
+    return token;
+  }
 
   return undefined;
 }
@@ -46,24 +54,65 @@ export const gatekeeper: RequestHandler = (req, res, next) => {
   }
 
   if (GATEKEEPER === "user_token" && token) {
-    const { user, result } = authenticate(token, req.ip);
+    // RisuAI users all come from a handful of aws lambda IPs so we cannot use
+    // IP alone to distinguish between them and prevent usertoken sharing.
+    // Risu sends a signed token in the request headers with an anonymous user
+    // ID that we can instead use to associate requests with an individual.
+    const ip = req.risuToken?.length
+      ? `risu${req.risuToken}-${req.ip}`
+      : req.ip;
+
+    const { user, result } = authenticate(token, ip);
 
     switch (result) {
       case "success":
         req.user = user;
         return next();
       case "limited":
-        return res.status(403).json({
-          error: `Forbidden: no more IPs can authenticate with this token`,
-        });
+        return sendError(
+          req,
+          res,
+          403,
+          `Forbidden: no more IP addresses allowed for this user token`,
+          { currentIp: ip, maxIps: user?.maxIps }
+        );
       case "disabled":
         const bannedUser = getUser(token);
         if (bannedUser?.disabledAt) {
-          const reason = bannedUser.disabledReason || "Token disabled";
-          return res.status(403).json({ error: `Forbidden: ${reason}` });
+          const reason = bannedUser.disabledReason || "User token disabled";
+          return sendError(req, res, 403, `Forbidden: ${reason}`);
         }
     }
   }
 
-  res.status(401).json({ error: "Unauthorized" });
+  sendError(req, res, 401, "Unauthorized");
 };
+
+function sendError(
+  req: Request,
+  res: Response,
+  status: number,
+  message: string,
+  data: any = {}
+) {
+  const isPost = req.method === "POST";
+  const hasBody = isPost && req.body;
+  const hasModel = hasBody && req.body.model;
+
+  if (!hasModel) {
+    return res.status(status).json({ error: message });
+  }
+
+  sendErrorToClient({
+    req,
+    res,
+    options: {
+      title: `Proxy gatekeeper error (HTTP ${status})`,
+      message,
+      format: "unknown",
+      statusCode: status,
+      reqId: req.id,
+      obj: data,
+    },
+  });
+}

src/proxy/gcp.ts

@@ -0,0 +1,196 @@
+import { Request, RequestHandler, Router } from "express";
+import { config } from "../config";
+import { transformAnthropicChatResponseToOpenAI } from "./anthropic";
+import { ipLimiter } from "./rate-limit";
+import {
+  createPreprocessorMiddleware,
+  finalizeSignedRequest,
+  signGcpRequest,
+} from "./middleware/request";
+import { ProxyResHandlerWithBody } from "./middleware/response";
+import { createQueuedProxyMiddleware } from "./middleware/request/proxy-middleware-factory";
+
+const LATEST_GCP_SONNET_MINOR_VERSION = "20240229";
+
+let modelsCache: any = null;
+let modelsCacheTime = 0;
+
+const getModelsResponse = () => {
+  if (new Date().getTime() - modelsCacheTime < 1000 * 60) {
+    return modelsCache;
+  }
+
+  if (!config.gcpCredentials) return { object: "list", data: [] };
+
+  // https://docs.anthropic.com/en/docs/about-claude/models
+  const variants = [
+    "claude-3-haiku@20240307",
+    "claude-3-5-haiku@20241022",
+    "claude-3-sonnet@20240229",
+    "claude-3-5-sonnet@20240620",
+    "claude-3-5-sonnet-v2@20241022",
+    "claude-3-opus@20240229",
+  ];
+
+  const models = variants.map((id) => ({
+    id,
+    object: "model",
+    created: new Date().getTime(),
+    owned_by: "anthropic",
+    permission: [],
+    root: "claude",
+    parent: null,
+  }));
+
+  modelsCache = { object: "list", data: models };
+  modelsCacheTime = new Date().getTime();
+
+  return modelsCache;
+};
+
+const handleModelRequest: RequestHandler = (_req, res) => {
+  res.status(200).json(getModelsResponse());
+};
+
+const gcpBlockingResponseHandler: ProxyResHandlerWithBody = async (
+  _proxyRes,
+  req,
+  res,
+  body
+) => {
+  if (typeof body !== "object") {
+    throw new Error("Expected body to be an object");
+  }
+
+  let newBody = body;
+  switch (`${req.inboundApi}<-${req.outboundApi}`) {
+    case "openai<-anthropic-chat":
+      req.log.info("Transforming Anthropic Chat back to OpenAI format");
+      newBody = transformAnthropicChatResponseToOpenAI(body);
+      break;
+  }
+
+  res.status(200).json({ ...newBody, proxy: body.proxy });
+};
+
+const gcpProxy = createQueuedProxyMiddleware({
+  target: ({ signedRequest }) => {
+    if (!signedRequest) throw new Error("Must sign request before proxying");
+    return `${signedRequest.protocol}//${signedRequest.hostname}`;
+  },
+  mutations: [signGcpRequest, finalizeSignedRequest],
+  blockingResponseHandler: gcpBlockingResponseHandler,
+});
+
+const oaiToChatPreprocessor = createPreprocessorMiddleware(
+  { inApi: "openai", outApi: "anthropic-chat", service: "gcp" },
+  { afterTransform: [maybeReassignModel] }
+);
+
+/**
+ * Routes an OpenAI prompt to either the legacy Claude text completion endpoint
+ * or the new Claude chat completion endpoint, based on the requested model.
+ */
+const preprocessOpenAICompatRequest: RequestHandler = (req, res, next) => {
+  oaiToChatPreprocessor(req, res, next);
+};
+
+const gcpRouter = Router();
+gcpRouter.get("/v1/models", handleModelRequest);
+// Native Anthropic chat completion endpoint.
+gcpRouter.post(
+  "/v1/messages",
+  ipLimiter,
+  createPreprocessorMiddleware(
+    { inApi: "anthropic-chat", outApi: "anthropic-chat", service: "gcp" },
+    { afterTransform: [maybeReassignModel] }
+  ),
+  gcpProxy
+);
+
+// OpenAI-to-GCP Anthropic compatibility endpoint.
+gcpRouter.post(
+  "/v1/chat/completions",
+  ipLimiter,
+  preprocessOpenAICompatRequest,
+  gcpProxy
+);
+
+/**
+ * Tries to deal with:
+ * - frontends sending GCP model names even when they want to use the OpenAI-
+ *   compatible endpoint
+ * - frontends sending Anthropic model names that GCP doesn't recognize
+ * - frontends sending OpenAI model names because they expect the proxy to
+ *   translate them
+ *
+ * If client sends GCP model ID it will be used verbatim. Otherwise, various
+ * strategies are used to try to map a non-GCP model name to GCP model ID.
+ */
+function maybeReassignModel(req: Request) {
+  const model = req.body.model;
+
+  // If it looks like an GCP model, use it as-is
+  // if (model.includes("anthropic.claude")) {
+  if (model.startsWith("claude-") && model.includes("@")) {
+    return;
+  }
+
+  // Anthropic model names can look like:
+  // - claude-v1
+  // - claude-2.1
+  // - claude-3-5-sonnet-20240620-v1:0
+  const pattern =
+    /^(claude-)?(instant-)?(v)?(\d+)([.-](\d{1}))?(-\d+k)?(-sonnet-|-opus-|-haiku-)?(\d*)/i;
+  const match = model.match(pattern);
+
+  // If there's no match, fallback to Claude3 Sonnet as it is most likely to be
+  // available on GCP.
+  if (!match) {
+    req.body.model = `claude-3-sonnet@${LATEST_GCP_SONNET_MINOR_VERSION}`;
+    return;
+  }
+
+  const [_, _cl, instant, _v, major, _sep, minor, _ctx, name, rev] = match;
+
+  // TODO: rework this to function similarly to aws-claude.ts maybeReassignModel
+  const ver = minor ? `${major}.${minor}` : major;
+  switch (ver) {
+    case "3":
+    case "3.0":
+      if (name.includes("opus")) {
+        req.body.model = "claude-3-opus@20240229";
+      } else if (name.includes("haiku")) {
+        req.body.model = "claude-3-haiku@20240307";
+      } else {
+        req.body.model = "claude-3-sonnet@20240229";
+      }
+      return;
+    case "3.5":
+      switch (name) {
+        case "sonnet":
+          switch (rev) {
+            case "20241022":
+            case "latest":
+              req.body.model = "claude-3-5-sonnet-v2@20241022";
+              return;
+            case "20240620":
+              req.body.model = "claude-3-5-sonnet@20240620";
+              return;
+          }
+          break;
+        case "haiku":
+          req.body.model = "claude-3-5-haiku@20241022";
+          return;
+        case "opus":
+          // Add after model ids are announced late 2024
+          break;
+      }
+  }
+
+  // Fallback to Claude3 Sonnet
+  req.body.model = `claude-3-sonnet@${LATEST_GCP_SONNET_MINOR_VERSION}`;
+  return;
+}
+
+export const gcp = gcpRouter;

src/proxy/google-ai.ts

@@ -1,26 +1,22 @@
 import { Request, RequestHandler, Router } from "express";
-import { createProxyMiddleware } from "http-proxy-middleware";
 import { v4 } from "uuid";
+import { GoogleAIKey, keyPool } from "../shared/key-management";
 import { config } from "../config";
-import { logger } from "../logger";
-import { createQueueMiddleware } from "./queue";
 import { ipLimiter } from "./rate-limit";
-import { handleProxyError } from "./middleware/common";
 import {
-  createOnProxyReqHandler,
   createPreprocessorMiddleware,
   finalizeSignedRequest,
-  forceModel,
 } from "./middleware/request";
-import {
-  createOnProxyResHandler,
-  ProxyResHandlerWithBody,
-} from "./middleware/response";
-import { addGoogleAIKey } from "./middleware/request/preprocessors/add-google-ai-key";
+import { ProxyResHandlerWithBody } from "./middleware/response";
+import { addGoogleAIKey } from "./middleware/request/mutators/add-google-ai-key";
+import { createQueuedProxyMiddleware } from "./middleware/request/proxy-middleware-factory";
 
 let modelsCache: any = null;
 let modelsCacheTime = 0;
 
+// https://ai.google.dev/models/gemini
+// TODO: list models https://ai.google.dev/tutorials/rest_quickstart#list_models
+
 const getModelsResponse = () => {
   if (new Date().getTime() - modelsCacheTime < 1000 * 60) {
     return modelsCache;
@@ -28,9 +24,19 @@ const getModelsResponse = () => {
 
   if (!config.googleAIKey) return { object: "list", data: [] };
 
-  const googleAIVariants = ["gemini-pro"];
+  const keys = keyPool
+    .list()
+    .filter((k) => k.service === "google-ai") as GoogleAIKey[];
+  if (keys.length === 0) {
+    modelsCache = { object: "list", data: [] };
+    modelsCacheTime = new Date().getTime();
+    return modelsCache;
+  }
 
-  const models = googleAIVariants.map((id) => ({
+  const modelIds = Array.from(
+    new Set(keys.map((k) => k.modelIds).flat())
+  ).filter((id) => id.startsWith("models/gemini"));
+  const models = modelIds.map((id) => ({
     id,
     object: "model",
     created: new Date().getTime(),
@@ -50,8 +56,7 @@ const handleModelRequest: RequestHandler = (_req, res) => {
   res.status(200).json(getModelsResponse());
 };
 
-/** Only used for non-streaming requests. */
-const googleAIResponseHandler: ProxyResHandlerWithBody = async (
+const googleAIBlockingResponseHandler: ProxyResHandlerWithBody = async (
   _proxyRes,
   req,
   res,
@@ -61,21 +66,13 @@ const googleAIResponseHandler: ProxyResHandlerWithBody = async (
     throw new Error("Expected body to be an object");
   }
 
-  if (config.promptLogging) {
-    const host = req.get("host");
-    body.proxy_note = `Prompts are logged on this proxy instance. See ${host} for more information.`;
-  }
-
+  let newBody = body;
   if (req.inboundApi === "openai") {
     req.log.info("Transforming Google AI response to OpenAI format");
-    body = transformGoogleAIResponse(body, req);
+    newBody = transformGoogleAIResponse(body, req);
   }
 
-  if (req.tokenizerInfo) {
-    body.proxy_tokenizer = req.tokenizerInfo;
-  }
-
-  res.status(200).json(body);
+  res.status(200).json({ ...newBody, proxy: body.proxy });
 };
 
 function transformGoogleAIResponse(
@@ -105,36 +102,75 @@ function transformGoogleAIResponse(
   };
 }
 
-const googleAIProxy = createQueueMiddleware({
-  beforeProxy: addGoogleAIKey,
-  proxyMiddleware: createProxyMiddleware({
-    target: "bad-target-will-be-rewritten",
-    router: ({ signedRequest }) => {
-      const { protocol, hostname, path } = signedRequest;
-      return `${protocol}//${hostname}${path}`;
-    },
-    changeOrigin: true,
-    selfHandleResponse: true,
-    logger,
-    on: {
-      proxyReq: createOnProxyReqHandler({ pipeline: [finalizeSignedRequest] }),
-      proxyRes: createOnProxyResHandler([googleAIResponseHandler]),
-      error: handleProxyError,
-    },
-  }),
+const googleAIProxy = createQueuedProxyMiddleware({
+  target: ({ signedRequest }) => {
+    if (!signedRequest) throw new Error("Must sign request before proxying");
+    const { protocol, hostname} = signedRequest;
+    return `${protocol}//${hostname}`;
+  },
+  mutations: [addGoogleAIKey, finalizeSignedRequest],
+  blockingResponseHandler: googleAIBlockingResponseHandler,
 });
 
 const googleAIRouter = Router();
 googleAIRouter.get("/v1/models", handleModelRequest);
+
+// Native Google AI chat completion endpoint
+googleAIRouter.post(
+  "/v1beta/models/:modelId:(generateContent|streamGenerateContent)",
+  ipLimiter,
+  createPreprocessorMiddleware(
+    { inApi: "google-ai", outApi: "google-ai", service: "google-ai" },
+    { beforeTransform: [maybeReassignModel], afterTransform: [setStreamFlag] }
+  ),
+  googleAIProxy
+);
+
 // OpenAI-to-Google AI compatibility endpoint.
 googleAIRouter.post(
   "/v1/chat/completions",
   ipLimiter,
   createPreprocessorMiddleware(
     { inApi: "openai", outApi: "google-ai", service: "google-ai" },
-    { afterTransform: [forceModel("gemini-pro")] }
+    { afterTransform: [maybeReassignModel] }
   ),
   googleAIProxy
 );
 
+function setStreamFlag(req: Request) {
+  const isStreaming = req.url.includes("streamGenerateContent");
+  if (isStreaming) {
+    req.body.stream = true;
+    req.isStreaming = true;
+  } else {
+    req.body.stream = false;
+    req.isStreaming = false;
+  }
+}
+
+/**
+ * Replaces requests for non-Google AI models with gemini-1.5-pro-latest.
+ * Also strips models/ from the beginning of the model IDs.
+ **/
+function maybeReassignModel(req: Request) {
+  // Ensure model is on body as a lot of middleware will expect it.
+  const model = req.body.model || req.url.split("/").pop()?.split(":").shift();
+  if (!model) {
+    throw new Error("You must specify a model with your request.");
+  }
+  req.body.model = model;
+
+  const requested = model;
+  if (requested.startsWith("models/")) {
+    req.body.model = requested.slice("models/".length);
+  }
+
+  if (requested.includes("gemini")) {
+    return;
+  }
+
+  req.log.info({ requested }, "Reassigning model to gemini-1.5-pro-latest");
+  req.body.model = "gemini-1.5-pro-latest";
+}
+
 export const googleAI = googleAIRouter;

src/proxy/middleware/common.ts

@@ -1,16 +1,22 @@
 import { Request, Response } from "express";
-import httpProxy from "http-proxy";
+import http from "http";
+import { Socket } from "net";
 import { ZodError } from "zod";
 import { generateErrorMessage } from "zod-error";
-import { makeCompletionSSE } from "../../shared/streaming";
+import { HttpError } from "../../shared/errors";
 import { assertNever } from "../../shared/utils";
 import { QuotaExceededError } from "./request/preprocessors/apply-quota-limits";
+import { sendErrorToClient } from "./response/error-generator";
 
 const OPENAI_CHAT_COMPLETION_ENDPOINT = "/v1/chat/completions";
 const OPENAI_TEXT_COMPLETION_ENDPOINT = "/v1/completions";
 const OPENAI_EMBEDDINGS_ENDPOINT = "/v1/embeddings";
 const OPENAI_IMAGE_COMPLETION_ENDPOINT = "/v1/images/generations";
 const ANTHROPIC_COMPLETION_ENDPOINT = "/v1/complete";
+const ANTHROPIC_MESSAGES_ENDPOINT = "/v1/messages";
+const ANTHROPIC_SONNET_COMPAT_ENDPOINT = "/v1/sonnet";
+const ANTHROPIC_OPUS_COMPAT_ENDPOINT = "/v1/opus";
+const GOOGLE_AI_COMPLETION_ENDPOINT = "/v1beta/models";
 
 export function isTextGenerationRequest(req: Request) {
   return (
@@ -19,6 +25,10 @@ export function isTextGenerationRequest(req: Request) {
       OPENAI_CHAT_COMPLETION_ENDPOINT,
       OPENAI_TEXT_COMPLETION_ENDPOINT,
       ANTHROPIC_COMPLETION_ENDPOINT,
+      ANTHROPIC_MESSAGES_ENDPOINT,
+      ANTHROPIC_SONNET_COMPAT_ENDPOINT,
+      ANTHROPIC_OPUS_COMPAT_ENDPOINT,
+      GOOGLE_AI_COMPLETION_ENDPOINT,
     ].some((endpoint) => req.path.startsWith(endpoint))
   );
 }
@@ -36,7 +46,7 @@ export function isEmbeddingsRequest(req: Request) {
   );
 }
 
-export function writeErrorResponse(
+export function sendProxyError(
   req: Request,
   res: Response,
   statusCode: number,
@@ -46,51 +56,48 @@ export function writeErrorResponse(
   const msg =
     statusCode === 500
       ? `The proxy encountered an error while trying to process your prompt.`
-      : `The proxy encountered an error while trying to send your prompt to the upstream service.`;
+      : `The proxy encountered an error while trying to send your prompt to the API.`;
 
-  // If we're mid-SSE stream, send a data event with the error payload and end
-  // the stream. Otherwise just send a normal error response.
-  if (
-    res.headersSent ||
-    String(res.getHeader("content-type")).startsWith("text/event-stream")
-  ) {
-    const event = makeCompletionSSE({
+  sendErrorToClient({
+    options: {
       format: req.inboundApi,
       title: `Proxy error (HTTP ${statusCode} ${statusMessage})`,
-      message: `${msg} Further technical details are provided below.`,
+      message: `${msg} Further details are provided below.`,
       obj: errorPayload,
       reqId: req.id,
       model: req.body?.model,
-    });
-    res.write(event);
-    res.write(`data: [DONE]\n\n`);
-    res.end();
-  } else {
-    if (req.tokenizerInfo && typeof errorPayload.error === "object") {
-      errorPayload.error.proxy_tokenizer = req.tokenizerInfo;
-    }
-    res.status(statusCode).json(errorPayload);
-  }
+    },
+    req,
+    res,
+  });
 }
 
-export const handleProxyError: httpProxy.ErrorCallback = (err, req, res) => {
-  req.log.error(err, `Error during http-proxy-middleware request`);
-  classifyErrorAndSend(err, req as Request, res as Response);
-};
-
+/**
+ * Handles errors thrown during preparation of a proxy request (before it is
+ * sent to the upstream API), typically due to validation, quota, or other
+ * pre-flight checks. Depending on the error class, this function will send an
+ * appropriate error response to the client, streaming it if necessary.
+ */
 export const classifyErrorAndSend = (
   err: Error,
   req: Request,
-  res: Response
+  res: Response | Socket
 ) => {
+  if (res instanceof Socket) {
+    // We should always have an Express response object here, but http-proxy's
+    // ErrorCallback type says it could be just a Socket.
+    req.log.error(err, "Caught error while proxying request to target but cannot send error response to client.");
+    return res.destroy();
+  }
   try {
     const { statusCode, statusMessage, userMessage, ...errorDetails } =
       classifyError(err);
-    writeErrorResponse(req, res, statusCode, statusMessage, {
+    sendProxyError(req, res, statusCode, statusMessage, {
       error: { message: userMessage, ...errorDetails },
     });
   } catch (error) {
     req.log.error(error, `Error writing error response headers, giving up.`);
+    res.end();
   }
 };
 
@@ -113,6 +120,35 @@ function classifyError(err: Error): {
   };
 
   switch (err.constructor.name) {
+    case "HttpError":
+      const statusCode = (err as HttpError).status;
+      return {
+        statusCode,
+        statusMessage: `HTTP ${statusCode} ${http.STATUS_CODES[statusCode]}`,
+        userMessage: `Reverse proxy error: ${err.message}`,
+        type: "proxy_http_error",
+      };
+    case "BadRequestError":
+      return {
+        statusCode: 400,
+        statusMessage: "Bad Request",
+        userMessage: `Request is not valid. (${err.message})`,
+        type: "proxy_bad_request",
+      };
+    case "NotFoundError":
+      return {
+        statusCode: 404,
+        statusMessage: "Not Found",
+        userMessage: `Requested resource not found. (${err.message})`,
+        type: "proxy_not_found",
+      };
+    case "PaymentRequiredError":
+      return {
+        statusCode: 402,
+        statusMessage: "No Keys Available",
+        userMessage: err.message,
+        type: "proxy_no_keys_available",
+      };
     case "ZodError":
       const userMessage = generateErrorMessage((err as ZodError).issues, {
         prefix: "Request validation failed. ",
@@ -194,14 +230,32 @@ export function getCompletionFromBody(req: Request, body: Record<string, any>) {
   switch (format) {
     case "openai":
     case "mistral-ai":
-      return body.choices[0].message.content;
+      // Few possible values:
+      // - choices[0].message.content
+      // - choices[0].message with no content if model is invoking a tool
+      return body.choices?.[0]?.message?.content || "";
+    case "mistral-text":
+      return body.outputs?.[0]?.text || "";
     case "openai-text":
       return body.choices[0].text;
-    case "anthropic":
+    case "anthropic-chat":
+      if (!body.content) {
+        req.log.error(
+          { body: JSON.stringify(body) },
+          "Received empty Anthropic chat completion"
+        );
+        return "";
+      }
+      return body.content
+        .map(({ text, type }: { type: string; text: string }) =>
+          type === "text" ? text : `[Unsupported content type: ${type}]`
+        )
+        .join("\n");
+    case "anthropic-text":
       if (!body.completion) {
         req.log.error(
           { body: JSON.stringify(body) },
-          "Received empty Anthropic completion"
+          "Received empty Anthropic text completion"
         );
         return "";
       }
@@ -210,7 +264,15 @@ export function getCompletionFromBody(req: Request, body: Record<string, any>) {
       if ("choices" in body) {
         return body.choices[0].message.content;
       }
-      return body.candidates[0].content.parts[0].text;
+      const text = body.candidates[0].content?.parts?.[0]?.text;
+      if (!text) {
+        req.log.warn(
+          { body: JSON.stringify(body) },
+          "Received empty Google AI text completion"
+        );
+        return "";
+      }
+      return text;
     case "openai-image":
       return body.data?.map((item: any) => item.url).join("\n");
     default:
@@ -218,21 +280,22 @@ export function getCompletionFromBody(req: Request, body: Record<string, any>) {
   }
 }
 
-export function getModelFromBody(req: Request, body: Record<string, any>) {
+export function getModelFromBody(req: Request, resBody: Record<string, any>) {
   const format = req.outboundApi;
   switch (format) {
     case "openai":
     case "openai-text":
+      return resBody.model;
     case "mistral-ai":
-      return body.model;
+    case "mistral-text":
     case "openai-image":
-      return req.body.model;
-    case "anthropic":
-      // Anthropic confirms the model in the response, but AWS Claude doesn't.
-      return body.model || req.body.model;
     case "google-ai":
-      // Google doesn't confirm the model in the response.
+      // These formats don't have a model in the response body.
       return req.body.model;
+    case "anthropic-chat":
+    case "anthropic-text":
+      // Anthropic confirms the model in the response, but AWS Claude doesn't.
+      return resBody.model || req.body.model;
     default:
       assertNever(format);
   }

src/proxy/middleware/request/index.ts

@@ -1,42 +1,38 @@
 import type { Request } from "express";
-import type { ClientRequest } from "http";
-import type { ProxyReqCallback } from "http-proxy";
 
-export { createOnProxyReqHandler } from "./onproxyreq-factory";
+import { ProxyReqManager } from "./proxy-req-manager";
 export {
   createPreprocessorMiddleware,
   createEmbeddingsPreprocessorMiddleware,
 } from "./preprocessor-factory";
 
-// Express middleware (runs before http-proxy-middleware, can be async)
-export { addAzureKey } from "./preprocessors/add-azure-key";
+// Preprocessors (runs before request is queued, usually body transformation/validation)
 export { applyQuotaLimits } from "./preprocessors/apply-quota-limits";
-export { validateContextSize } from "./preprocessors/validate-context-size";
+export { blockZoomerOrigins } from "./preprocessors/block-zoomer-origins";
 export { countPromptTokens } from "./preprocessors/count-prompt-tokens";
 export { languageFilter } from "./preprocessors/language-filter";
 export { setApiFormat } from "./preprocessors/set-api-format";
-export { signAwsRequest } from "./preprocessors/sign-aws-request";
 export { transformOutboundPayload } from "./preprocessors/transform-outbound-payload";
+export { validateContextSize } from "./preprocessors/validate-context-size";
+export { validateModelFamily } from "./preprocessors/validate-model-family";
+export { validateVision } from "./preprocessors/validate-vision";
 
-// http-proxy-middleware callbacks (runs on onProxyReq, cannot be async)
-export { addKey, addKeyForEmbeddingsRequest } from "./onproxyreq/add-key";
-export { addAnthropicPreamble } from "./onproxyreq/add-anthropic-preamble";
-export { blockZoomerOrigins } from "./onproxyreq/block-zoomer-origins";
-export { checkModelFamily } from "./onproxyreq/check-model-family";
-export { finalizeBody } from "./onproxyreq/finalize-body";
-export { finalizeSignedRequest } from "./onproxyreq/finalize-signed-request";
-export { stripHeaders } from "./onproxyreq/strip-headers";
+// Proxy request mutators (runs every time request is dequeued, before proxying, usually for auth/signing)
+export { addKey, addKeyForEmbeddingsRequest } from "./mutators/add-key";
+export { addAzureKey } from "./mutators/add-azure-key";
+export { finalizeBody } from "./mutators/finalize-body";
+export { finalizeSignedRequest } from "./mutators/finalize-signed-request";
+export { signAwsRequest } from "./mutators/sign-aws-request";
+export { signGcpRequest } from "./mutators/sign-vertex-ai-request";
+export { stripHeaders } from "./mutators/strip-headers";
 
 /**
- * Middleware that runs prior to the request being handled by http-proxy-
- * middleware.
+ * Middleware that runs prior to the request being queued or handled by
+ * http-proxy-middleware. You will not have access to the proxied
+ * request/response objects since they have not yet been sent to the API.
  *
- * Async functions can be used here, but you will not have access to the proxied
- * request/response objects, nor the data set by ProxyRequestMiddleware
- * functions as they have not yet been run.
- *
- * User will have been authenticated by the time this middleware runs, but your
- * request won't have been assigned an API key yet.
+ * User will have been authenticated by the proxy's gatekeeper, but the request
+ * won't have been assigned an upstream API key yet.
  *
  * Note that these functions only run once ever per request, even if the request
  * is automatically retried by the request queue middleware.
@@ -44,17 +40,14 @@ export { stripHeaders } from "./onproxyreq/strip-headers";
 export type RequestPreprocessor = (req: Request) => void | Promise<void>;
 
 /**
- * Callbacks that run immediately before the request is sent to the API in
- * response to http-proxy-middleware's `proxyReq` event.
+ * Middleware that runs immediately before the request is proxied to the
+ * upstream API, after dequeueing the request from the request queue.
  *
- * Async functions cannot be used here as HPM's event emitter is not async and
- * will not wait for the promise to resolve before sending the request.
- *
- * Note that these functions may be run multiple times per request if the
- * first attempt is rate limited and the request is automatically retried by the
- * request queue middleware.
+ * Because these middleware may be run multiple times per request if a retryable
+ * error occurs and the request put back in the queue, they must be idempotent.
+ * A change manager is provided to allow the middleware to make changes to the
+ * request which can be automatically reverted.
  */
-export type HPMRequestCallback = ProxyReqCallback<ClientRequest, Request>;
-
-export const forceModel = (model: string) => (req: Request) =>
-  void (req.body.model = model);
+export type ProxyReqMutator = (
+  changeManager: ProxyReqManager
+) => void | Promise<void>;

src/proxy/middleware/request/mutators/add-azure-key.ts

@@ -0,0 +1,84 @@
+import {
+  APIFormat,
+  AzureOpenAIKey,
+  keyPool,
+} from "../../../../shared/key-management";
+import { ProxyReqMutator } from "../index";
+
+export const addAzureKey: ProxyReqMutator = async (manager) => {
+  const req = manager.request;
+  const validAPIs: APIFormat[] = ["openai", "openai-image"];
+  const apisValid = [req.outboundApi, req.inboundApi].every((api) =>
+    validAPIs.includes(api)
+  );
+  const serviceValid = req.service === "azure";
+
+  if (!apisValid || !serviceValid) {
+    throw new Error("addAzureKey called on invalid request");
+  }
+
+  if (!req.body?.model) {
+    throw new Error("You must specify a model with your request.");
+  }
+
+  const model = req.body.model.startsWith("azure-")
+    ? req.body.model
+    : `azure-${req.body.model}`;
+  // TODO: untracked mutation to body, I think this should just be a
+  // RequestPreprocessor because we don't need to do it every dequeue.
+  req.body.model = model;
+
+  const key = keyPool.get(model, "azure");
+  manager.setKey(key);
+
+  // Handles the sole Azure API deviation from the OpenAI spec (that I know of)
+  // TODO: this should also probably be a RequestPreprocessor
+  const notNullOrUndefined = (x: any) => x !== null && x !== undefined;
+  if ([req.body.logprobs, req.body.top_logprobs].some(notNullOrUndefined)) {
+    // OpenAI wants logprobs: true/false and top_logprobs: number
+    // Azure seems to just want to combine them into logprobs: number
+    // if (typeof req.body.logprobs === "boolean") {
+    //   req.body.logprobs = req.body.top_logprobs || undefined;
+    //   delete req.body.top_logprobs
+    // }
+
+    // Temporarily just disabling logprobs for Azure because their model support
+    // is random: `This model does not support the 'logprobs' parameter.`
+    delete req.body.logprobs;
+    delete req.body.top_logprobs;
+  }
+
+  req.log.info(
+    { key: key.hash, model },
+    "Assigned Azure OpenAI key to request"
+  );
+
+  const cred = req.key as AzureOpenAIKey;
+  const { resourceName, deploymentId, apiKey } = getCredentialsFromKey(cred);
+
+  const operation =
+    req.outboundApi === "openai" ? "/chat/completions" : "/images/generations";
+  const apiVersion =
+    req.outboundApi === "openai" ? "2023-09-01-preview" : "2024-02-15-preview";
+
+  manager.setSignedRequest({
+    method: "POST",
+    protocol: "https:",
+    hostname: `${resourceName}.openai.azure.com`,
+    path: `/openai/deployments/${deploymentId}${operation}?api-version=${apiVersion}`,
+    headers: {
+      ["host"]: `${resourceName}.openai.azure.com`,
+      ["content-type"]: "application/json",
+      ["api-key"]: apiKey,
+    },
+    body: JSON.stringify(req.body),
+  });
+};
+
+function getCredentialsFromKey(key: AzureOpenAIKey) {
+  const [resourceName, deploymentId, apiKey] = key.key.split(":");
+  if (!resourceName || !deploymentId || !apiKey) {
+    throw new Error("Assigned Azure OpenAI key is not in the correct format.");
+  }
+  return { resourceName, deploymentId, apiKey };
+}

src/proxy/middleware/request/mutators/add-google-ai-key.ts

@@ -0,0 +1,44 @@
+import { keyPool } from "../../../../shared/key-management";
+import { ProxyReqMutator } from "../index";
+
+export const addGoogleAIKey: ProxyReqMutator = (manager) => {
+  const req = manager.request;
+  const inboundValid =
+    req.inboundApi === "openai" || req.inboundApi === "google-ai";
+  const outboundValid = req.outboundApi === "google-ai";
+
+  const serviceValid = req.service === "google-ai";
+  if (!inboundValid || !outboundValid || !serviceValid) {
+    throw new Error("addGoogleAIKey called on invalid request");
+  }
+
+  const model = req.body.model;
+  const key = keyPool.get(model, "google-ai");
+  manager.setKey(key);
+
+  req.log.info(
+    { key: key.hash, model, stream: req.isStreaming },
+    "Assigned Google AI API key to request"
+  );
+
+  // https://generativelanguage.googleapis.com/v1beta/models/$MODEL_ID:generateContent?key=$API_KEY
+  // https://generativelanguage.googleapis.com/v1beta/models/$MODEL_ID:streamGenerateContent?key=${API_KEY}
+  const payload = { ...req.body, stream: undefined, model: undefined };
+
+  // TODO: this isn't actually signed, so the manager api is a little unclear
+  // with the ProxyReqManager refactor, it's probably no longer necesasry to
+  // do this because we can modify the path using Manager.setPath.
+  manager.setSignedRequest({
+    method: "POST",
+    protocol: "https:",
+    hostname: "generativelanguage.googleapis.com",
+    path: `/v1beta/models/${model}:${
+      req.isStreaming ? "streamGenerateContent?alt=sse&" : "generateContent?"
+    }key=${key.key}`,
+    headers: {
+      ["host"]: `generativelanguage.googleapis.com`,
+      ["content-type"]: "application/json",
+    },
+    body: JSON.stringify(payload),
+  });
+};

src/proxy/middleware/request/mutators/add-key.ts

@@ -0,0 +1,130 @@
+import { AnthropicChatMessage } from "../../../../shared/api-schemas";
+import { containsImageContent } from "../../../../shared/api-schemas/anthropic";
+import { Key, OpenAIKey, keyPool } from "../../../../shared/key-management";
+import { isEmbeddingsRequest } from "../../common";
+import { assertNever } from "../../../../shared/utils";
+import { ProxyReqMutator } from "../index";
+
+export const addKey: ProxyReqMutator = (manager) => {
+  const req = manager.request;
+
+  let assignedKey: Key;
+  const { service, inboundApi, outboundApi, body } = req;
+
+  if (!inboundApi || !outboundApi) {
+    const err = new Error(
+      "Request API format missing. Did you forget to add the request preprocessor to your router?"
+    );
+    req.log.error({ inboundApi, outboundApi, path: req.path }, err.message);
+    throw err;
+  }
+
+  if (!body?.model) {
+    throw new Error("You must specify a model with your request.");
+  }
+
+  let needsMultimodal = false;
+  if (outboundApi === "anthropic-chat") {
+    needsMultimodal = containsImageContent(
+      body.messages as AnthropicChatMessage[]
+    );
+  }
+
+  if (inboundApi === outboundApi) {
+    assignedKey = keyPool.get(body.model, service, needsMultimodal);
+  } else {
+    switch (outboundApi) {
+      // If we are translating between API formats we may need to select a model
+      // for the user, because the provided model is for the inbound API.
+      // TODO: This whole else condition is probably no longer needed since API
+      // translation now reassigns the model earlier in the request pipeline.
+      case "anthropic-text":
+      case "anthropic-chat":
+      case "mistral-ai":
+      case "mistral-text":
+      case "google-ai":
+        assignedKey = keyPool.get(body.model, service);
+        break;
+      case "openai-text":
+        assignedKey = keyPool.get("gpt-3.5-turbo-instruct", service);
+        break;
+      case "openai-image":
+        assignedKey = keyPool.get("dall-e-3", service);
+        break;
+      case "openai":
+        throw new Error(
+          `Outbound API ${outboundApi} is not supported for ${inboundApi}`
+        );
+      default:
+        assertNever(outboundApi);
+    }
+  }
+
+  manager.setKey(assignedKey);
+  req.log.info(
+    { key: assignedKey.hash, model: body.model, inboundApi, outboundApi },
+    "Assigned key to request"
+  );
+
+  // TODO: KeyProvider should assemble all necessary headers
+  switch (assignedKey.service) {
+    case "anthropic":
+      manager.setHeader("X-API-Key", assignedKey.key);
+      if (!manager.request.headers["anthropic-version"]) {
+        manager.setHeader("anthropic-version", "2023-06-01");
+      }
+      break;
+    case "openai":
+      const key: OpenAIKey = assignedKey as OpenAIKey;
+      if (key.organizationId && !key.key.includes("svcacct")) {
+        manager.setHeader("OpenAI-Organization", key.organizationId);
+      }
+      manager.setHeader("Authorization", `Bearer ${assignedKey.key}`);
+      break;
+    case "mistral-ai":
+      manager.setHeader("Authorization", `Bearer ${assignedKey.key}`);
+      break;
+    case "azure":
+      const azureKey = assignedKey.key;
+      manager.setHeader("api-key", azureKey);
+      break;
+    case "aws":
+    case "gcp":
+    case "google-ai":
+      throw new Error("add-key should not be used for this service.");
+    default:
+      assertNever(assignedKey.service);
+  }
+};
+
+/**
+ * Special case for embeddings requests which don't go through the normal
+ * request pipeline.
+ */
+export const addKeyForEmbeddingsRequest: ProxyReqMutator = (manager) => {
+  const req = manager.request;
+  if (!isEmbeddingsRequest(req)) {
+    throw new Error(
+      "addKeyForEmbeddingsRequest called on non-embeddings request"
+    );
+  }
+
+  if (req.inboundApi !== "openai") {
+    throw new Error("Embeddings requests must be from OpenAI");
+  }
+
+  manager.setBody({ input: req.body.input, model: "text-embedding-ada-002" });
+
+  const key = keyPool.get("text-embedding-ada-002", "openai") as OpenAIKey;
+
+  manager.setKey(key);
+  req.log.info(
+    { key: key.hash, toApi: req.outboundApi },
+    "Assigned Turbo key to embeddings request"
+  );
+
+  manager.setHeader("Authorization", `Bearer ${key.key}`);
+  if (key.organizationId) {
+    manager.setHeader("OpenAI-Organization", key.organizationId);
+  }
+};

src/proxy/middleware/request/mutators/finalize-body.ts

@@ -0,0 +1,22 @@
+import type { ProxyReqMutator } from "../index";
+
+/** Finalize the rewritten request body. Must be the last mutator. */
+export const finalizeBody: ProxyReqMutator = (manager) => {
+  const req = manager.request;
+
+  if (["POST", "PUT", "PATCH"].includes(req.method ?? "") && req.body) {
+    // For image generation requests, remove stream flag.
+    if (req.outboundApi === "openai-image") {
+      delete req.body.stream;
+    }
+    // For anthropic text to chat requests, remove undefined prompt.
+    if (req.outboundApi === "anthropic-chat") {
+      delete req.body.prompt;
+    }
+
+    const serialized =
+      typeof req.body === "string" ? req.body : JSON.stringify(req.body);
+    manager.setHeader("Content-Length", String(Buffer.byteLength(serialized)));
+    manager.setBody(serialized);
+  }
+};

src/proxy/middleware/request/mutators/finalize-signed-request.ts

@@ -0,0 +1,32 @@
+import { ProxyReqMutator } from "../index";
+
+/**
+ * For AWS/GCP/Azure/Google requests, the body is signed earlier in the request
+ * pipeline, before the proxy middleware. This function just assigns the path
+ * and headers to the proxy request.
+ */
+export const finalizeSignedRequest: ProxyReqMutator = (manager) => {
+  const req = manager.request;
+  if (!req.signedRequest) {
+    throw new Error("Expected req.signedRequest to be set");
+  }
+
+  // The path depends on the selected model and the assigned key's region.
+  manager.setPath(req.signedRequest.path);
+
+  // Amazon doesn't want extra headers, so we need to remove all of them and
+  // reassign only the ones specified in the signed request.
+  const headers = req.signedRequest.headers;
+  Object.keys(headers).forEach((key) => {
+    manager.removeHeader(key);
+  });
+  Object.entries(req.signedRequest.headers).forEach(([key, value]) => {
+    manager.setHeader(key, value);
+  });
+  const serialized =
+    typeof req.signedRequest.body === "string"
+      ? req.signedRequest.body
+      : JSON.stringify(req.signedRequest.body);
+  manager.setHeader("Content-Length", String(Buffer.byteLength(serialized)));
+  manager.setBody(serialized);
+};

src/proxy/middleware/request/mutators/sign-aws-request.ts

@@ -0,0 +1,148 @@
+import express, { Request } from "express";
+import { Sha256 } from "@aws-crypto/sha256-js";
+import { SignatureV4 } from "@smithy/signature-v4";
+import { HttpRequest } from "@smithy/protocol-http";
+import {
+  AnthropicV1TextSchema,
+  AnthropicV1MessagesSchema,
+} from "../../../../shared/api-schemas";
+import { AwsBedrockKey, keyPool } from "../../../../shared/key-management";
+import {
+  AWSMistralV1ChatCompletionsSchema,
+  AWSMistralV1TextCompletionsSchema,
+} from "../../../../shared/api-schemas/mistral-ai";
+import { ProxyReqMutator } from "../index";
+
+const AMZ_HOST =
+  process.env.AMZ_HOST || "bedrock-runtime.%REGION%.amazonaws.com";
+
+/**
+ * Signs an outgoing AWS request with the appropriate headers modifies the
+ * request object in place to fix the path.
+ * This happens AFTER request transformation.
+ */
+export const signAwsRequest: ProxyReqMutator = async (manager) => {
+  const req = manager.request;
+  const { model, stream } = req.body;
+  const key = keyPool.get(model, "aws") as AwsBedrockKey;
+  manager.setKey(key);
+
+  const credential = getCredentialParts(req);
+  const host = AMZ_HOST.replace("%REGION%", credential.region);
+
+  // AWS only uses 2023-06-01 and does not actually check this header, but we
+  // set it so that the stream adapter always selects the correct transformer.
+  manager.setHeader("anthropic-version", "2023-06-01");
+
+  // If our key has an inference profile compatible with the requested model,
+  // we want to use the inference profile instead of the model ID when calling
+  // InvokeModel as that will give us higher rate limits.
+  const profile =
+    key.inferenceProfileIds.find((p) => p.includes(model)) || model;
+
+  // Uses the AWS SDK to sign a request, then modifies our HPM proxy request
+  // with the headers generated by the SDK.
+  const newRequest = new HttpRequest({
+    method: "POST",
+    protocol: "https:",
+    hostname: host,
+    path: `/model/${profile}/invoke${stream ? "-with-response-stream" : ""}`,
+    headers: {
+      ["Host"]: host,
+      ["content-type"]: "application/json",
+    },
+    body: JSON.stringify(getStrictlyValidatedBodyForAws(req)),
+  });
+
+  if (stream) {
+    newRequest.headers["x-amzn-bedrock-accept"] = "application/json";
+  } else {
+    newRequest.headers["accept"] = "*/*";
+  }
+
+  const { body, inboundApi, outboundApi } = req;
+  req.log.info(
+    { key: key.hash, model: body.model, profile, inboundApi, outboundApi },
+    "Assigned AWS credentials to request"
+  );
+
+  manager.setSignedRequest(await sign(newRequest, getCredentialParts(req)));
+};
+
+type Credential = {
+  accessKeyId: string;
+  secretAccessKey: string;
+  region: string;
+};
+
+function getCredentialParts(req: express.Request): Credential {
+  const [accessKeyId, secretAccessKey, region] = req.key!.key.split(":");
+
+  if (!accessKeyId || !secretAccessKey || !region) {
+    req.log.error(
+      { key: req.key!.hash },
+      "AWS_CREDENTIALS isn't correctly formatted; refer to the docs"
+    );
+    throw new Error("The key assigned to this request is invalid.");
+  }
+
+  return { accessKeyId, secretAccessKey, region };
+}
+
+async function sign(request: HttpRequest, credential: Credential) {
+  const { accessKeyId, secretAccessKey, region } = credential;
+
+  const signer = new SignatureV4({
+    sha256: Sha256,
+    credentials: { accessKeyId, secretAccessKey },
+    region,
+    service: "bedrock",
+  });
+
+  return signer.sign(request);
+}
+
+function getStrictlyValidatedBodyForAws(req: Readonly<Request>): unknown {
+  // AWS uses vendor API formats but imposes additional (more strict) validation
+  // rules, namely that extraneous parameters are not allowed. We will validate
+  // using the vendor's zod schema but apply `.strip` to ensure that any
+  // extraneous parameters are removed.
+  let strippedParams: Record<string, unknown> = {};
+  switch (req.outboundApi) {
+    case "anthropic-text":
+      strippedParams = AnthropicV1TextSchema.pick({
+        prompt: true,
+        max_tokens_to_sample: true,
+        stop_sequences: true,
+        temperature: true,
+        top_k: true,
+        top_p: true,
+      })
+        .strip()
+        .parse(req.body);
+      break;
+    case "anthropic-chat":
+      strippedParams = AnthropicV1MessagesSchema.pick({
+        messages: true,
+        system: true,
+        max_tokens: true,
+        stop_sequences: true,
+        temperature: true,
+        top_k: true,
+        top_p: true,
+      })
+        .strip()
+        .parse(req.body);
+      strippedParams.anthropic_version = "bedrock-2023-05-31";
+      break;
+    case "mistral-ai":
+      strippedParams = AWSMistralV1ChatCompletionsSchema.parse(req.body);
+      break;
+    case "mistral-text":
+      strippedParams = AWSMistralV1TextCompletionsSchema.parse(req.body);
+      break;
+    default:
+      throw new Error("Unexpected outbound API for AWS.");
+  }
+  return strippedParams;
+}

src/proxy/middleware/request/mutators/sign-vertex-ai-request.ts

@@ -0,0 +1,75 @@
+import { AnthropicV1MessagesSchema } from "../../../../shared/api-schemas";
+import { GcpKey, keyPool } from "../../../../shared/key-management";
+import { ProxyReqMutator } from "../index";
+import {
+  getCredentialsFromGcpKey,
+  refreshGcpAccessToken,
+} from "../../../../shared/key-management/gcp/oauth";
+
+const GCP_HOST = process.env.GCP_HOST || "%REGION%-aiplatform.googleapis.com";
+
+export const signGcpRequest: ProxyReqMutator = async (manager) => {
+  const req = manager.request;
+  const serviceValid = req.service === "gcp";
+  if (!serviceValid) {
+    throw new Error("addVertexAIKey called on invalid request");
+  }
+
+  if (!req.body?.model) {
+    throw new Error("You must specify a model with your request.");
+  }
+
+  const { model } = req.body;
+  const key: GcpKey = keyPool.get(model, "gcp") as GcpKey;
+
+  if (!key.accessToken || Date.now() > key.accessTokenExpiresAt) {
+    const [token, durationSec] = await refreshGcpAccessToken(key);
+    keyPool.update(key, {
+      accessToken: token,
+      accessTokenExpiresAt: Date.now() + durationSec * 1000 * 0.95,
+    } as GcpKey);
+    // nb: key received by `get` is a clone and will not have the new access
+    // token we just set, so it must be manually updated.
+    key.accessToken = token;
+  }
+
+  manager.setKey(key);
+  req.log.info({ key: key.hash, model }, "Assigned GCP key to request");
+
+  // TODO: This should happen in transform-outbound-payload.ts
+  // TODO: Support tools
+  let strippedParams: Record<string, unknown>;
+  strippedParams = AnthropicV1MessagesSchema.pick({
+    messages: true,
+    system: true,
+    max_tokens: true,
+    stop_sequences: true,
+    temperature: true,
+    top_k: true,
+    top_p: true,
+    stream: true,
+  })
+    .strip()
+    .parse(req.body);
+  strippedParams.anthropic_version = "vertex-2023-10-16";
+
+  const credential = await getCredentialsFromGcpKey(key);
+
+  const host = GCP_HOST.replace("%REGION%", credential.region);
+  // GCP doesn't use the anthropic-version header, but we set it to ensure the
+  // stream adapter selects the correct transformer.
+  manager.setHeader("anthropic-version", "2023-06-01");
+
+  manager.setSignedRequest({
+    method: "POST",
+    protocol: "https:",
+    hostname: host,
+    path: `/v1/projects/${credential.projectId}/locations/${credential.region}/publishers/anthropic/models/${model}:streamRawPredict`,
+    headers: {
+      ["host"]: host,
+      ["content-type"]: "application/json",
+      ["authorization"]: `Bearer ${key.accessToken}`,
+    },
+    body: JSON.stringify(strippedParams),
+  });
+};

src/proxy/middleware/request/mutators/strip-headers.ts

@@ -0,0 +1,33 @@
+import { ProxyReqMutator } from "../index";
+
+/**
+ * Removes origin and referer headers before sending the request to the API for
+ * privacy reasons.
+ */
+export const stripHeaders: ProxyReqMutator = (manager) => {
+  manager.removeHeader("origin");
+  manager.removeHeader("referer");
+
+  // Some APIs refuse requests coming from browsers to discourage embedding
+  // API keys in client-side code, so we must remove all CORS/fetch headers.
+  Object.keys(manager.request.headers).forEach((key) => {
+    if (key.startsWith("sec-")) {
+      manager.removeHeader(key);
+    }
+  });
+
+  manager.removeHeader("tailscale-user-login");
+  manager.removeHeader("tailscale-user-name");
+  manager.removeHeader("tailscale-headers-info");
+  manager.removeHeader("tailscale-user-profile-pic");
+  manager.removeHeader("cf-connecting-ip");
+  manager.removeHeader("cf-ray");
+  manager.removeHeader("cf-visitor");
+  manager.removeHeader("cf-warp-tag-id");
+  manager.removeHeader("forwarded");
+  manager.removeHeader("true-client-ip");
+  manager.removeHeader("x-forwarded-for");
+  manager.removeHeader("x-forwarded-host");
+  manager.removeHeader("x-forwarded-proto");
+  manager.removeHeader("x-real-ip");
+};

src/proxy/middleware/request/onproxyreq-factory.ts

@@ -1,45 +0,0 @@
-import {
-  applyQuotaLimits,
-  blockZoomerOrigins,
-  checkModelFamily,
-  HPMRequestCallback,
-  stripHeaders,
-} from "./index";
-
-type ProxyReqHandlerFactoryOptions = { pipeline: HPMRequestCallback[] };
-
-/**
- * Returns an http-proxy-middleware request handler that runs the given set of
- * onProxyReq callback functions in sequence.
- *
- * These will run each time a request is proxied, including on automatic retries
- * by the queue after encountering a rate limit.
- */
-export const createOnProxyReqHandler = ({
-  pipeline,
-}: ProxyReqHandlerFactoryOptions): HPMRequestCallback => {
-  const callbackPipeline = [
-    checkModelFamily,
-    applyQuotaLimits,
-    blockZoomerOrigins,
-    stripHeaders,
-    ...pipeline,
-  ];
-  return (proxyReq, req, res, options) => {
-    // The streaming flag must be set before any other onProxyReq handler runs,
-    // as it may influence the behavior of subsequent handlers.
-    // Image generation requests can't be streamed.
-    // TODO: this flag is set in too many places
-    req.isStreaming =
-      req.isStreaming || req.body.stream === true || req.body.stream === "true";
-    req.body.stream = req.isStreaming;
-
-    try {
-      for (const fn of callbackPipeline) {
-        fn(proxyReq, req, res, options);
-      }
-    } catch (error) {
-      proxyReq.destroy(error);
-    }
-  };
-};

src/proxy/middleware/request/onproxyreq/add-anthropic-preamble.ts

@@ -1,32 +0,0 @@
-import { AnthropicKey, Key } from "../../../../shared/key-management";
-import { isTextGenerationRequest } from "../../common";
-import { HPMRequestCallback } from "../index";
-
-/**
- * Some keys require the prompt to start with `\n\nHuman:`. There is no way to
- * know this without trying to send the request and seeing if it fails. If a
- * key is marked as requiring a preamble, it will be added here.
- */
-export const addAnthropicPreamble: HPMRequestCallback = (
-  _proxyReq,
-  req
-) => {
-  if (!isTextGenerationRequest(req) || req.key?.service !== "anthropic") {
-    return;
-  }
-
-  let preamble = "";
-  let prompt = req.body.prompt;
-  assertAnthropicKey(req.key);
-  if (req.key.requiresPreamble) {
-    preamble = prompt.startsWith("\n\nHuman:") ? "" : "\n\nHuman:";
-    req.log.debug({ key: req.key.hash, preamble }, "Adding preamble to prompt");
-  }
-  req.body.prompt = preamble + prompt;
-};
-
-function assertAnthropicKey(key: Key): asserts key is AnthropicKey {
-  if (key.service !== "anthropic") {
-    throw new Error(`Expected an Anthropic key, got '${key.service}'`);
-  }
-}

src/proxy/middleware/request/onproxyreq/add-key.ts

@@ -1,121 +0,0 @@
-import { Key, OpenAIKey, keyPool } from "../../../../shared/key-management";
-import { isEmbeddingsRequest } from "../../common";
-import { HPMRequestCallback } from "../index";
-import { assertNever } from "../../../../shared/utils";
-
-/** Add a key that can service this request to the request object. */
-export const addKey: HPMRequestCallback = (proxyReq, req) => {
-  let assignedKey: Key;
-
-  if (!req.inboundApi || !req.outboundApi) {
-    const err = new Error(
-      "Request API format missing. Did you forget to add the request preprocessor to your router?"
-    );
-    req.log.error(
-      { in: req.inboundApi, out: req.outboundApi, path: req.path },
-      err.message
-    );
-    throw err;
-  }
-
-  if (!req.body?.model) {
-    throw new Error("You must specify a model with your request.");
-  }
-
-  if (req.inboundApi === req.outboundApi) {
-    assignedKey = keyPool.get(req.body.model);
-  } else {
-    switch (req.outboundApi) {
-      // If we are translating between API formats we may need to select a model
-      // for the user, because the provided model is for the inbound API.
-      case "anthropic":
-        assignedKey = keyPool.get("claude-v1");
-        break;
-      case "openai-text":
-        assignedKey = keyPool.get("gpt-3.5-turbo-instruct");
-        break;
-      case "openai":
-        throw new Error(
-          "OpenAI Chat as an API translation target is not supported"
-        );
-      case "google-ai":
-        throw new Error("add-key should not be used for this model.");
-      case "mistral-ai":
-        throw new Error("Mistral AI should never be translated");
-      case "openai-image":
-        assignedKey = keyPool.get("dall-e-3");
-        break;
-      default:
-        assertNever(req.outboundApi);
-    }
-  }
-
-  req.key = assignedKey;
-  req.log.info(
-    {
-      key: assignedKey.hash,
-      model: req.body?.model,
-      fromApi: req.inboundApi,
-      toApi: req.outboundApi,
-    },
-    "Assigned key to request"
-  );
-
-  // TODO: KeyProvider should assemble all necessary headers
-  switch (assignedKey.service) {
-    case "anthropic":
-      proxyReq.setHeader("X-API-Key", assignedKey.key);
-      break;
-    case "openai":
-      const key: OpenAIKey = assignedKey as OpenAIKey;
-      if (key.organizationId) {
-        proxyReq.setHeader("OpenAI-Organization", key.organizationId);
-      }
-    case "mistral-ai":
-      proxyReq.setHeader("Authorization", `Bearer ${assignedKey.key}`);
-      break;
-    case "azure":
-      const azureKey = assignedKey.key;
-      proxyReq.setHeader("api-key", azureKey);
-      break;
-    case "aws":
-    case "google-ai":
-      throw new Error("add-key should not be used for this service.");
-    default:
-      assertNever(assignedKey.service);
-  }
-};
-
-/**
- * Special case for embeddings requests which don't go through the normal
- * request pipeline.
- */
-export const addKeyForEmbeddingsRequest: HPMRequestCallback = (
-  proxyReq,
-  req
-) => {
-  if (!isEmbeddingsRequest(req)) {
-    throw new Error(
-      "addKeyForEmbeddingsRequest called on non-embeddings request"
-    );
-  }
-
-  if (req.inboundApi !== "openai") {
-    throw new Error("Embeddings requests must be from OpenAI");
-  }
-
-  req.body = { input: req.body.input, model: "text-embedding-ada-002" };
-
-  const key = keyPool.get("text-embedding-ada-002") as OpenAIKey;
-
-  req.key = key;
-  req.log.info(
-    { key: key.hash, toApi: req.outboundApi },
-    "Assigned Turbo key to embeddings request"
-  );
-
-  proxyReq.setHeader("Authorization", `Bearer ${key.key}`);
-  if (key.organizationId) {
-    proxyReq.setHeader("OpenAI-Organization", key.organizationId);
-  }
-};

src/proxy/middleware/request/onproxyreq/finalize-body.ts

@@ -1,19 +0,0 @@
-import { fixRequestBody } from "http-proxy-middleware";
-import type { HPMRequestCallback } from "../index";
-
-/** Finalize the rewritten request body. Must be the last rewriter. */
-export const finalizeBody: HPMRequestCallback = (proxyReq, req) => {
-  if (["POST", "PUT", "PATCH"].includes(req.method ?? "") && req.body) {
-    // For image generation requests, remove stream flag.
-    if (req.outboundApi === "openai-image") {
-      delete req.body.stream;
-    }
-
-    const updatedBody = JSON.stringify(req.body);
-    proxyReq.setHeader("Content-Length", Buffer.byteLength(updatedBody));
-    (req as any).rawBody = Buffer.from(updatedBody);
-
-    // body-parser and http-proxy-middleware don't play nice together
-    fixRequestBody(proxyReq, req);
-  }
-};

src/proxy/middleware/request/onproxyreq/finalize-signed-request.ts

@@ -1,26 +0,0 @@
-import type { HPMRequestCallback } from "../index";
-
-/**
- * For AWS/Azure/Google requests, the body is signed earlier in the request
- * pipeline, before the proxy middleware. This function just assigns the path
- * and headers to the proxy request.
- */
-export const finalizeSignedRequest: HPMRequestCallback = (proxyReq, req) => {
-  if (!req.signedRequest) {
-    throw new Error("Expected req.signedRequest to be set");
-  }
-
-  // The path depends on the selected model and the assigned key's region.
-  proxyReq.path = req.signedRequest.path;
-
-  // Amazon doesn't want extra headers, so we need to remove all of them and
-  // reassign only the ones specified in the signed request.
-  proxyReq.getRawHeaderNames().forEach(proxyReq.removeHeader.bind(proxyReq));
-  Object.entries(req.signedRequest.headers).forEach(([key, value]) => {
-    proxyReq.setHeader(key, value);
-  });
-
-  // Don't use fixRequestBody here because it adds a content-length header.
-  // Amazon doesn't want that and it breaks the signature.
-  proxyReq.write(req.signedRequest.body);
-};

src/proxy/middleware/request/onproxyreq/strip-headers.ts

@@ -1,16 +0,0 @@
-import { HPMRequestCallback } from "../index";
-
-/**
- * Removes origin and referer headers before sending the request to the API for
- * privacy reasons.
- **/
-export const stripHeaders: HPMRequestCallback = (proxyReq) => {
-  proxyReq.setHeader("origin", "");
-  proxyReq.setHeader("referer", "");
-
-  proxyReq.removeHeader("cf-connecting-ip");
-  proxyReq.removeHeader("forwarded");
-  proxyReq.removeHeader("true-client-ip");
-  proxyReq.removeHeader("x-forwarded-for");
-  proxyReq.removeHeader("x-real-ip");
-};

src/proxy/middleware/request/preprocessor-factory.ts

@@ -1,15 +1,19 @@
 import { RequestHandler } from "express";
+import { ZodIssue } from "zod";
 import { initializeSseStream } from "../../../shared/streaming";
 import { classifyErrorAndSend } from "../common";
 import {
   RequestPreprocessor,
-  validateContextSize,
+  blockZoomerOrigins,
   countPromptTokens,
+  languageFilter,
   setApiFormat,
   transformOutboundPayload,
-  languageFilter,
+  validateContextSize,
+  validateModelFamily,
+  validateVision,
+  applyQuotaLimits,
 } from ".";
-import { ZodIssue } from "zod";
 
 type RequestPreprocessorOptions = {
   /**
@@ -29,14 +33,15 @@ type RequestPreprocessorOptions = {
 /**
  * Returns a middleware function that processes the request body into the given
  * API format, and then sequentially runs the given additional preprocessors.
+ * These should be used for validation and transformations that only need to
+ * happen once per request.
  *
  * These run first in the request lifecycle, a single time per request before it
  * is added to the request queue. They aren't run again if the request is
  * re-attempted after a rate limit.
  *
- * To run a preprocessor on every re-attempt, pass it to createQueueMiddleware.
- * It will run after these preprocessors, but before the request is sent to
- * http-proxy-middleware.
+ * To run functions against requests every time they are re-attempted, write a
+ * ProxyReqMutator and pass it to createQueuedProxyMiddleware instead.
  */
 export const createPreprocessorMiddleware = (
   apiFormat: Parameters<typeof setApiFormat>[0],
@@ -44,12 +49,16 @@ export const createPreprocessorMiddleware = (
 ): RequestHandler => {
   const preprocessors: RequestPreprocessor[] = [
     setApiFormat(apiFormat),
+    blockZoomerOrigins,
     ...(beforeTransform ?? []),
     transformOutboundPayload,
     countPromptTokens,
     languageFilter,
     ...(afterTransform ?? []),
     validateContextSize,
+    validateVision,
+    validateModelFamily,
+    applyQuotaLimits,
   ];
   return async (...args) => executePreprocessors(preprocessors, args);
 };
@@ -71,6 +80,9 @@ async function executePreprocessors(
   preprocessors: RequestPreprocessor[],
   [req, res, next]: Parameters<RequestHandler>
 ) {
+  handleTestMessage(req, res, next);
+  if (res.headersSent) return;
+
   try {
     for (const preprocessor of preprocessors) {
       await preprocessor(req);
@@ -78,10 +90,10 @@ async function executePreprocessors(
     next();
   } catch (error) {
     if (error.constructor.name === "ZodError") {
-      const msg = error?.issues
-        ?.map((issue: ZodIssue) => issue.message)
+      const issues = error?.issues
+        ?.map((issue: ZodIssue) => `${issue.path.join(".")}: ${issue.message}`)
         .join("; ");
-      req.log.info(msg, "Prompt validation failed.");
+      req.log.warn({ issues }, "Prompt failed preprocessor validation.");
     } else {
       req.log.error(error, "Error while executing request preprocessor");
     }
@@ -99,3 +111,66 @@ async function executePreprocessors(
     classifyErrorAndSend(error as Error, req, res);
   }
 }
+
+/**
+ * Bypasses the API call and returns a test message response if the request body
+ * is a known test message from SillyTavern. Otherwise these messages just waste
+ * API request quota and confuse users when the proxy is busy, because ST always
+ * makes them with `stream: false` (which is not allowed when the proxy is busy)
+ */
+const handleTestMessage: RequestHandler = (req, res) => {
+  const { method, body } = req;
+  if (method !== "POST") {
+    return;
+  }
+
+  if (isTestMessage(body)) {
+    req.log.info({ body }, "Received test message. Skipping API call.");
+    res.json({
+      id: "test-message",
+      object: "chat.completion",
+      created: Date.now(),
+      model: body.model,
+      // openai chat
+      choices: [
+        {
+          message: { role: "assistant", content: "Hello!" },
+          finish_reason: "stop",
+          index: 0,
+        },
+      ],
+      // anthropic text
+      completion: "Hello!",
+      // anthropic chat
+      content: [{ type: "text", text: "Hello!" }],
+      // gemini
+      candidates: [
+        {
+          content: { parts: [{ text: "Hello!" }] },
+          finishReason: "stop",
+        },
+      ],
+      proxy_note:
+        "SillyTavern connection test detected. Your prompt was not sent to the actual model and this response was generated by the proxy.",
+    });
+  }
+};
+
+function isTestMessage(body: any) {
+  const { messages, prompt, contents } = body;
+
+  if (messages) {
+    return (
+      messages.length === 1 &&
+      messages[0].role === "user" &&
+      messages[0].content === "Hi"
+    );
+  } else if (contents) {
+    return contents.length === 1 && contents[0].parts[0]?.text === "Hi";
+  } else {
+    return (
+      prompt?.trim() === "Human: Hi\n\nAssistant:" ||
+      prompt?.startsWith("Hi\n\n")
+    );
+  }
+}

src/proxy/middleware/request/preprocessors/add-azure-key.ts

@@ -1,50 +0,0 @@
-import { AzureOpenAIKey, keyPool } from "../../../../shared/key-management";
-import { RequestPreprocessor } from "../index";
-
-export const addAzureKey: RequestPreprocessor = (req) => {
-  const apisValid = req.inboundApi === "openai" && req.outboundApi === "openai";
-  const serviceValid = req.service === "azure";
-  if (!apisValid || !serviceValid) {
-    throw new Error("addAzureKey called on invalid request");
-  }
-
-  if (!req.body?.model) {
-    throw new Error("You must specify a model with your request.");
-  }
-
-  const model = req.body.model.startsWith("azure-")
-    ? req.body.model
-    : `azure-${req.body.model}`;
-
-  req.key = keyPool.get(model);
-  req.body.model = model;
-
-  req.log.info(
-    { key: req.key.hash, model },
-    "Assigned Azure OpenAI key to request"
-  );
-
-  const cred = req.key as AzureOpenAIKey;
-  const { resourceName, deploymentId, apiKey } = getCredentialsFromKey(cred);
-
-  req.signedRequest = {
-    method: "POST",
-    protocol: "https:",
-    hostname: `${resourceName}.openai.azure.com`,
-    path: `/openai/deployments/${deploymentId}/chat/completions?api-version=2023-09-01-preview`,
-    headers: {
-      ["host"]: `${resourceName}.openai.azure.com`,
-      ["content-type"]: "application/json",
-      ["api-key"]: apiKey,
-    },
-    body: JSON.stringify(req.body),
-  };
-};
-
-function getCredentialsFromKey(key: AzureOpenAIKey) {
-  const [resourceName, deploymentId, apiKey] = key.key.split(":");
-  if (!resourceName || !deploymentId || !apiKey) {
-    throw new Error("Assigned Azure OpenAI key is not in the correct format.");
-  }
-  return { resourceName, deploymentId, apiKey };
-}

src/proxy/middleware/request/preprocessors/add-google-ai-key.ts

@@ -1,40 +0,0 @@
-import { keyPool } from "../../../../shared/key-management";
-import { RequestPreprocessor } from "../index";
-
-export const addGoogleAIKey: RequestPreprocessor = (req) => {
-  const apisValid = req.inboundApi === "openai" && req.outboundApi === "google-ai";
-  const serviceValid = req.service === "google-ai";
-  if (!apisValid || !serviceValid) {
-    throw new Error("addGoogleAIKey called on invalid request");
-  }
-
-  if (!req.body?.model) {
-    throw new Error("You must specify a model with your request.");
-  }
-
-  const model = req.body.model;
-  req.key = keyPool.get(model);
-
-  req.log.info(
-    { key: req.key.hash, model },
-    "Assigned Google AI API key to request"
-  );
-
-  // https://generativelanguage.googleapis.com/v1beta/models/$MODEL_ID:generateContent?key=$API_KEY
-  // https://generativelanguage.googleapis.com/v1beta/models/$MODEL_ID:streamGenerateContent?key=${API_KEY}
-
-  req.isStreaming = req.isStreaming || req.body.stream;
-  delete req.body.stream;
-
-  req.signedRequest = {
-    method: "POST",
-    protocol: "https:",
-    hostname: "generativelanguage.googleapis.com",
-    path: `/v1beta/models/${model}:${req.isStreaming ? "streamGenerateContent" : "generateContent"}?key=${req.key.key}`,
-    headers: {
-      ["host"]: `generativelanguage.googleapis.com`,
-      ["content-type"]: "application/json",
-    },
-    body: JSON.stringify(req.body),
-  };
-};

src/proxy/middleware/request/preprocessors/apply-quota-limits.ts

@@ -1,6 +1,6 @@
 import { hasAvailableQuota } from "../../../../shared/users/user-store";
 import { isImageGenerationRequest, isTextGenerationRequest } from "../../common";
-import { HPMRequestCallback } from "../index";
+import { RequestPreprocessor } from "../index";
 
 export class QuotaExceededError extends Error {
   public quotaInfo: any;
@@ -11,7 +11,7 @@ export class QuotaExceededError extends Error {
   }
 }
 
-export const applyQuotaLimits: HPMRequestCallback = (_proxyReq, req) => {
+export const applyQuotaLimits: RequestPreprocessor = (req) => {
   const subjectToQuota =
     isTextGenerationRequest(req) || isImageGenerationRequest(req);
   if (!subjectToQuota || !req.user) return;

src/proxy/middleware/request/preprocessors/block-zoomer-origins.ts

@@ -1,4 +1,4 @@
-import { HPMRequestCallback } from "../index";
+import { RequestPreprocessor } from "../index";
 
 const DISALLOWED_ORIGIN_SUBSTRINGS = "janitorai.com,janitor.ai".split(",");
 
@@ -13,7 +13,7 @@ class ZoomerForbiddenError extends Error {
  * Blocks requests from Janitor AI users with a fake, scary error message so I
  * stop getting emails asking for tech support.
  */
-export const blockZoomerOrigins: HPMRequestCallback = (_proxyReq, req) => {
+export const blockZoomerOrigins: RequestPreprocessor = (req) => {
   const origin = req.headers.origin || req.headers.referer;
   if (origin && DISALLOWED_ORIGIN_SUBSTRINGS.some((s) => origin.includes(s))) {
     // Venus-derivatives send a test prompt to check if the proxy is working.

src/proxy/middleware/request/preprocessors/count-prompt-tokens.ts

@@ -1,11 +1,11 @@
 import { RequestPreprocessor } from "../index";
 import { countTokens } from "../../../../shared/tokenization";
 import { assertNever } from "../../../../shared/utils";
-import type {
+import {
   GoogleAIChatMessage,
   MistralAIChatMessage,
   OpenAIChatMessage,
-} from "./transform-outbound-payload";
+} from "../../../../shared/api-schemas";
 
 /**
  * Given a request with an already-transformed body, counts the number of
@@ -17,7 +17,7 @@ export const countPromptTokens: RequestPreprocessor = async (req) => {
 
   switch (service) {
     case "openai": {
-      req.outputTokens = req.body.max_tokens;
+      req.outputTokens = req.body.max_completion_tokens || req.body.max_tokens;
       const prompt: OpenAIChatMessage[] = req.body.messages;
       result = await countTokens({ req, prompt, service });
       break;
@@ -28,7 +28,19 @@ export const countPromptTokens: RequestPreprocessor = async (req) => {
       result = await countTokens({ req, prompt, service });
       break;
     }
-    case "anthropic": {
+    case "anthropic-chat": {
+      req.outputTokens = req.body.max_tokens;
+      let system = req.body.system ?? "";
+      if (Array.isArray(system)) {
+        system = system
+          .map((m: { type: string; text: string }) => m.text)
+          .join("\n");
+      }
+      const prompt = { system, messages: req.body.messages };
+      result = await countTokens({ req, prompt, service });
+      break;
+    }
+    case "anthropic-text": {
       req.outputTokens = req.body.max_tokens_to_sample;
       const prompt: string = req.body.prompt;
       result = await countTokens({ req, prompt, service });
@@ -40,9 +52,11 @@ export const countPromptTokens: RequestPreprocessor = async (req) => {
       result = await countTokens({ req, prompt, service });
       break;
     }
-    case "mistral-ai": {
+    case "mistral-ai":
+    case "mistral-text": {
       req.outputTokens = req.body.max_tokens;
-      const prompt: MistralAIChatMessage[] = req.body.messages;
+      const prompt: string | MistralAIChatMessage[] =
+        req.body.messages ?? req.body.prompt;
       result = await countTokens({ req, prompt, service });
       break;
     }

src/proxy/middleware/request/preprocessors/language-filter.ts

@@ -1,12 +1,15 @@
 import { Request } from "express";
+import { z } from "zod";
 import { config } from "../../../../config";
 import { assertNever } from "../../../../shared/utils";
 import { RequestPreprocessor } from "../index";
-import { UserInputError } from "../../../../shared/errors";
+import { BadRequestError } from "../../../../shared/errors";
 import {
   MistralAIChatMessage,
   OpenAIChatMessage,
-} from "./transform-outbound-payload";
+  flattenAnthropicMessages,
+} from "../../../../shared/api-schemas";
+import { GoogleAIV1GenerateContentSchema } from "../../../../shared/api-schemas/google-ai";
 
 const rejectedClients = new Map<string, number>();
 
@@ -45,16 +48,20 @@ export const languageFilter: RequestPreprocessor = async (req) => {
       req.res!.once("close", resolve);
       setTimeout(resolve, delay);
     });
-    throw new UserInputError(config.rejectMessage);
+    throw new BadRequestError(config.rejectMessage);
   }
 };
 
+/* 
+TODO: this is not type safe and does not raise errors if request body zod schema
+is changed.
+*/
 function getPromptFromRequest(req: Request) {
   const service = req.outboundApi;
   const body = req.body;
   switch (service) {
-    case "anthropic":
-      return body.prompt;
+    case "anthropic-chat":
+      return flattenAnthropicMessages(body.messages);
     case "openai":
     case "mistral-ai":
       return body.messages
@@ -69,11 +76,18 @@ function getPromptFromRequest(req: Request) {
           return `${msg.role}: ${text}`;
         })
         .join("\n\n");
+    case "anthropic-text":
     case "openai-text":
     case "openai-image":
+    case "mistral-text":
       return body.prompt;
-    case "google-ai":
-      return body.prompt.text;
+    case "google-ai": {
+      const b = body as z.infer<typeof GoogleAIV1GenerateContentSchema>;
+      return [
+        b.systemInstruction?.parts.map((p) => p.text),
+        ...b.contents.flatMap((c) => c.parts.map((p) => p.text)),
+      ].join("\n");
+    }
     default:
       assertNever(service);
   }

src/proxy/middleware/request/preprocessors/set-api-format.ts

@@ -4,8 +4,22 @@ import { LLMService } from "../../../../shared/models";
 import { RequestPreprocessor } from "../index";
 
 export const setApiFormat = (api: {
+  /**
+   * The API format the user made the request in and expects the response to be
+   * in.
+   */
   inApi: Request["inboundApi"];
+  /**
+   * The API format the proxy will make the request in and expects the response
+   * to be in. If different from `inApi`, the proxy will transform the user's
+   * request body to this format, and will transform the response body or stream
+   * events from this format.
+   */
   outApi: APIFormat;
+  /**
+   * The service the request will be sent to, which determines authentication
+   * and possibly the streaming transport.
+   */
   service: LLMService;
 }): RequestPreprocessor => {
   return function configureRequestApiFormat(req) {

src/proxy/middleware/request/preprocessors/sign-aws-request.ts

@@ -1,96 +0,0 @@
-import express from "express";
-import { Sha256 } from "@aws-crypto/sha256-js";
-import { SignatureV4 } from "@smithy/signature-v4";
-import { HttpRequest } from "@smithy/protocol-http";
-import { keyPool } from "../../../../shared/key-management";
-import { RequestPreprocessor } from "../index";
-import { AnthropicV1CompleteSchema } from "./transform-outbound-payload";
-
-const AMZ_HOST =
-  process.env.AMZ_HOST || "bedrock-runtime.%REGION%.amazonaws.com";
-
-/**
- * Signs an outgoing AWS request with the appropriate headers modifies the
- * request object in place to fix the path.
- */
-export const signAwsRequest: RequestPreprocessor = async (req) => {
-  req.key = keyPool.get("anthropic.claude-v2");
-
-  const { model, stream } = req.body;
-  req.isStreaming = stream === true || stream === "true";
-
-  let preamble = req.body.prompt.startsWith("\n\nHuman:") ? "" : "\n\nHuman:";
-  req.body.prompt = preamble + req.body.prompt;
-
-  // AWS supports only a subset of Anthropic's parameters and is more strict
-  // about unknown parameters.
-  // TODO: This should happen in transform-outbound-payload.ts
-  const strippedParams = AnthropicV1CompleteSchema.pick({
-    prompt: true,
-    max_tokens_to_sample: true,
-    stop_sequences: true,
-    temperature: true,
-    top_k: true,
-    top_p: true,
-  }).strip().parse(req.body);
-
-  const credential = getCredentialParts(req);
-  const host = AMZ_HOST.replace("%REGION%", credential.region);
-  // AWS only uses 2023-06-01 and does not actually check this header, but we
-  // set it so that the stream adapter always selects the correct transformer.
-  req.headers["anthropic-version"] = "2023-06-01";
-
-  // Uses the AWS SDK to sign a request, then modifies our HPM proxy request
-  // with the headers generated by the SDK.
-  const newRequest = new HttpRequest({
-    method: "POST",
-    protocol: "https:",
-    hostname: host,
-    path: `/model/${model}/invoke${stream ? "-with-response-stream" : ""}`,
-    headers: {
-      ["Host"]: host,
-      ["content-type"]: "application/json",
-    },
-    body: JSON.stringify(strippedParams),
-  });
-
-  if (stream) {
-    newRequest.headers["x-amzn-bedrock-accept"] = "application/json";
-  } else {
-    newRequest.headers["accept"] = "*/*";
-  }
-
-  req.signedRequest = await sign(newRequest, getCredentialParts(req));
-};
-
-type Credential = {
-  accessKeyId: string;
-  secretAccessKey: string;
-  region: string;
-};
-function getCredentialParts(req: express.Request): Credential {
-  const [accessKeyId, secretAccessKey, region] = req.key!.key.split(":");
-
-  if (!accessKeyId || !secretAccessKey || !region) {
-    req.log.error(
-      { key: req.key!.hash },
-      "AWS_CREDENTIALS isn't correctly formatted; refer to the docs"
-    );
-    throw new Error("The key assigned to this request is invalid.");
-  }
-
-  return { accessKeyId, secretAccessKey, region };
-}
-
-async function sign(request: HttpRequest, credential: Credential) {
-  const { accessKeyId, secretAccessKey, region } = credential;
-
-  const signer = new SignatureV4({
-    sha256: Sha256,
-    credentials: { accessKeyId, secretAccessKey },
-    region,
-    service: "bedrock",
-  });
-
-  return signer.sign(request);
-}

src/proxy/middleware/request/preprocessors/transform-outbound-payload.ts

@@ -1,524 +1,89 @@
 import { Request } from "express";
-import { z } from "zod";
-import { config } from "../../../../config";
 import {
-  isTextGenerationRequest,
+  API_REQUEST_VALIDATORS,
+  API_REQUEST_TRANSFORMERS,
+} from "../../../../shared/api-schemas";
+import { BadRequestError } from "../../../../shared/errors";
+import { fixMistralPrompt } from "../../../../shared/api-schemas/mistral-ai";
+import {
   isImageGenerationRequest,
+  isTextGenerationRequest,
 } from "../../common";
 import { RequestPreprocessor } from "../index";
-import { APIFormat } from "../../../../shared/key-management";
-
-const CLAUDE_OUTPUT_MAX = config.maxOutputTokensAnthropic;
-const OPENAI_OUTPUT_MAX = config.maxOutputTokensOpenAI;
-
-// TODO: move schemas to shared
-
-// https://console.anthropic.com/docs/api/reference#-v1-complete
-export const AnthropicV1CompleteSchema = z
-  .object({
-    model: z.string().max(100),
-    prompt: z.string({
-      required_error:
-        "No prompt found. Are you sending an OpenAI-formatted request to the Claude endpoint?",
-    }),
-    max_tokens_to_sample: z.coerce
-      .number()
-      .int()
-      .transform((v) => Math.min(v, CLAUDE_OUTPUT_MAX)),
-    stop_sequences: z.array(z.string().max(500)).optional(),
-    stream: z.boolean().optional().default(false),
-    temperature: z.coerce.number().optional().default(1),
-    top_k: z.coerce.number().optional(),
-    top_p: z.coerce.number().optional(),
-  })
-  .strip();
-
-// https://platform.openai.com/docs/api-reference/chat/create
-const OpenAIV1ChatContentArraySchema = z.array(
-  z.union([
-    z.object({ type: z.literal("text"), text: z.string() }),
-    z.object({
-      type: z.literal("image_url"),
-      image_url: z.object({
-        url: z.string().url(),
-        detail: z.enum(["low", "auto", "high"]).optional().default("auto"),
-      }),
-    }),
-  ])
-);
-
-export const OpenAIV1ChatCompletionSchema = z
-  .object({
-    model: z.string().max(100),
-    messages: z.array(
-      z.object({
-        role: z.enum(["system", "user", "assistant"]),
-        content: z.union([z.string(), OpenAIV1ChatContentArraySchema]),
-        name: z.string().optional(),
-      }),
-      {
-        required_error:
-          "No `messages` found. Ensure you've set the correct completion endpoint.",
-        invalid_type_error:
-          "Messages were not formatted correctly. Refer to the OpenAI Chat API documentation for more information.",
-      }
-    ),
-    temperature: z.number().optional().default(1),
-    top_p: z.number().optional().default(1),
-    n: z
-      .literal(1, {
-        errorMap: () => ({
-          message: "You may only request a single completion at a time.",
-        }),
-      })
-      .optional(),
-    stream: z.boolean().optional().default(false),
-    stop: z
-      .union([z.string().max(500), z.array(z.string().max(500))])
-      .optional(),
-    max_tokens: z.coerce
-      .number()
-      .int()
-      .nullish()
-      .default(16)
-      .transform((v) => Math.min(v ?? OPENAI_OUTPUT_MAX, OPENAI_OUTPUT_MAX)),
-    frequency_penalty: z.number().optional().default(0),
-    presence_penalty: z.number().optional().default(0),
-    logit_bias: z.any().optional(),
-    user: z.string().max(500).optional(),
-    seed: z.number().int().optional(),
-  })
-  .strip();
-
-export type OpenAIChatMessage = z.infer<
-  typeof OpenAIV1ChatCompletionSchema
->["messages"][0];
-
-const OpenAIV1TextCompletionSchema = z
-  .object({
-    model: z
-      .string()
-      .max(100)
-      .regex(
-        /^gpt-3.5-turbo-instruct/,
-        "Model must start with 'gpt-3.5-turbo-instruct'"
-      ),
-    prompt: z.string({
-      required_error:
-        "No `prompt` found. Ensure you've set the correct completion endpoint.",
-    }),
-    logprobs: z.number().int().nullish().default(null),
-    echo: z.boolean().optional().default(false),
-    best_of: z.literal(1).optional(),
-    stop: z
-      .union([z.string().max(500), z.array(z.string().max(500)).max(4)])
-      .optional(),
-    suffix: z.string().max(1000).optional(),
-  })
-  .strip()
-  .merge(OpenAIV1ChatCompletionSchema.omit({ messages: true }));
-
-// https://platform.openai.com/docs/api-reference/images/create
-const OpenAIV1ImagesGenerationSchema = z
-  .object({
-    prompt: z.string().max(4000),
-    model: z.string().max(100).optional(),
-    quality: z.enum(["standard", "hd"]).optional().default("standard"),
-    n: z.number().int().min(1).max(4).optional().default(1),
-    response_format: z.enum(["url", "b64_json"]).optional(),
-    size: z
-      .enum(["256x256", "512x512", "1024x1024", "1792x1024", "1024x1792"])
-      .optional()
-      .default("1024x1024"),
-    style: z.enum(["vivid", "natural"]).optional().default("vivid"),
-    user: z.string().max(500).optional(),
-  })
-  .strip();
-
-// https://developers.generativeai.google/api/rest/generativelanguage/models/generateContent
-const GoogleAIV1GenerateContentSchema = z
-  .object({
-    model: z.string().max(100), //actually specified in path but we need it for the router
-    stream: z.boolean().optional().default(false), // also used for router
-    contents: z.array(
-      z.object({
-        parts: z.array(z.object({ text: z.string() })),
-        role: z.enum(["user", "model"]),
-      })
-    ),
-    tools: z.array(z.object({})).max(0).optional(),
-    safetySettings: z.array(z.object({})).max(0).optional(),
-    generationConfig: z.object({
-      temperature: z.number().optional(),
-      maxOutputTokens: z.coerce
-        .number()
-        .int()
-        .optional()
-        .default(16)
-        .transform((v) => Math.min(v, 1024)), // TODO: Add config
-      candidateCount: z.literal(1).optional(),
-      topP: z.number().optional(),
-      topK: z.number().optional(),
-      stopSequences: z.array(z.string().max(500)).max(5).optional(),
-    }),
-  })
-  .strip();
-
-export type GoogleAIChatMessage = z.infer<
-  typeof GoogleAIV1GenerateContentSchema
->["contents"][0];
-
-// https://docs.mistral.ai/api#operation/createChatCompletion
-const MistralAIV1ChatCompletionsSchema = z.object({
-  model: z.string(),
-  messages: z.array(
-    z.object({
-      role: z.enum(["system", "user", "assistant"]),
-      content: z.string(),
-    })
-  ),
-  temperature: z.number().optional().default(0.7),
-  top_p: z.number().optional().default(1),
-  max_tokens: z.coerce
-    .number()
-    .int()
-    .nullish()
-    .transform((v) => Math.min(v ?? OPENAI_OUTPUT_MAX, OPENAI_OUTPUT_MAX)),
-  stream: z.boolean().optional().default(false),
-  safe_mode: z.boolean().optional().default(false),
-  random_seed: z.number().int().optional(),
-});
-
-export type MistralAIChatMessage = z.infer<
-  typeof MistralAIV1ChatCompletionsSchema
->["messages"][0];
-
-const VALIDATORS: Record<APIFormat, z.ZodSchema<any>> = {
-  anthropic: AnthropicV1CompleteSchema,
-  openai: OpenAIV1ChatCompletionSchema,
-  "openai-text": OpenAIV1TextCompletionSchema,
-  "openai-image": OpenAIV1ImagesGenerationSchema,
-  "google-ai": GoogleAIV1GenerateContentSchema,
-  "mistral-ai": MistralAIV1ChatCompletionsSchema,
-};
 
 /** Transforms an incoming request body to one that matches the target API. */
 export const transformOutboundPayload: RequestPreprocessor = async (req) => {
-  const sameService = req.inboundApi === req.outboundApi;
   const alreadyTransformed = req.retryCount > 0;
   const notTransformable =
     !isTextGenerationRequest(req) && !isImageGenerationRequest(req);
 
-  if (alreadyTransformed || notTransformable) return;
-
-  if (sameService) {
-    const result = VALIDATORS[req.inboundApi].safeParse(req.body);
-    if (!result.success) {
-      req.log.error(
-        { issues: result.error.issues, body: req.body },
-        "Request validation failed"
-      );
-      throw result.error;
-    }
-    req.body = result.data;
+  if (alreadyTransformed) {
+    return;
+  } else if (notTransformable) {
+    // This is probably an indication of a bug in the proxy.
+    const { inboundApi, outboundApi, method, path } = req;
+    req.log.warn(
+      { inboundApi, outboundApi, method, path },
+      "`transformOutboundPayload` called on a non-transformable request."
+    );
     return;
   }
 
-  if (req.inboundApi === "openai" && req.outboundApi === "anthropic") {
-    req.body = openaiToAnthropic(req);
+  applyMistralPromptFixes(req);
+
+  // Native prompts are those which were already provided by the client in the
+  // target API format. We don't need to transform them.
+  const isNativePrompt = req.inboundApi === req.outboundApi;
+  if (isNativePrompt) {
+    const result = API_REQUEST_VALIDATORS[req.inboundApi].parse(req.body);
+    req.body = result;
     return;
   }
 
-  if (req.inboundApi === "openai" && req.outboundApi === "google-ai") {
-    req.body = openaiToGoogleAI(req);
+  // Prompt requires translation from one API format to another.
+  const transformation = `${req.inboundApi}->${req.outboundApi}` as const;
+  const transFn = API_REQUEST_TRANSFORMERS[transformation];
+
+  if (transFn) {
+    req.log.info({ transformation }, "Transforming request...");
+    req.body = await transFn(req);
     return;
   }
 
-  if (req.inboundApi === "openai" && req.outboundApi === "openai-text") {
-    req.body = openaiToOpenaiText(req);
-    return;
-  }
-
-  if (req.inboundApi === "openai" && req.outboundApi === "openai-image") {
-    req.body = openaiToOpenaiImage(req);
-    return;
-  }
-
-  throw new Error(
-    `'${req.inboundApi}' -> '${req.outboundApi}' request proxying is not supported. Make sure your client is configured to use the correct API.`
+  throw new BadRequestError(
+    `${transformation} proxying is not supported. Make sure your client is configured to send requests in the correct format and to the correct endpoint.`
   );
 };
 
-function openaiToAnthropic(req: Request) {
-  const { body } = req;
-  const result = OpenAIV1ChatCompletionSchema.safeParse(body);
-  if (!result.success) {
-    req.log.warn(
-      { issues: result.error.issues, body },
-      "Invalid OpenAI-to-Anthropic request"
+// handles weird cases that don't fit into our abstractions
+function applyMistralPromptFixes(req: Request): void {
+  if (req.inboundApi === "mistral-ai") {
+    // Mistral Chat is very similar to OpenAI but not identical and many clients
+    // don't properly handle the differences. We will try to validate the
+    // mistral prompt and try to fix it if it fails. It will be re-validated
+    // after this function returns.
+    const result = API_REQUEST_VALIDATORS["mistral-ai"].parse(req.body);
+    req.body.messages = fixMistralPrompt(result.messages);
+    req.log.info(
+      { n: req.body.messages.length, prev: result.messages.length },
+      "Applied Mistral chat prompt fixes."
     );
-    throw result.error;
-  }
 
-  req.headers["anthropic-version"] = "2023-06-01";
-
-  const { messages, ...rest } = result.data;
-  const prompt = openAIMessagesToClaudePrompt(messages);
-
-  let stops = rest.stop
-    ? Array.isArray(rest.stop)
-      ? rest.stop
-      : [rest.stop]
-    : [];
-  // Recommended by Anthropic
-  stops.push("\n\nHuman:");
-  // Helps with jailbreak prompts that send fake system messages and multi-bot
-  // chats that prefix bot messages with "System: Respond as <bot name>".
-  stops.push("\n\nSystem:");
-  // Remove duplicates
-  stops = [...new Set(stops)];
-
-  return {
-    // Model may be overridden in `calculate-context-size.ts` to avoid having
-    // a circular dependency (`calculate-context-size.ts` needs an already-
-    // transformed request body to count tokens, but this function would like
-    // to know the count to select a model).
-    model: process.env.CLAUDE_SMALL_MODEL || "claude-v1",
-    prompt: prompt,
-    max_tokens_to_sample: rest.max_tokens,
-    stop_sequences: stops,
-    stream: rest.stream,
-    temperature: rest.temperature,
-    top_p: rest.top_p,
-  };
-}
-
-function openaiToOpenaiText(req: Request) {
-  const { body } = req;
-  const result = OpenAIV1ChatCompletionSchema.safeParse(body);
-  if (!result.success) {
-    req.log.warn(
-      { issues: result.error.issues, body },
-      "Invalid OpenAI-to-OpenAI-text request"
-    );
-    throw result.error;
-  }
-
-  const { messages, ...rest } = result.data;
-  const prompt = flattenOpenAIChatMessages(messages);
-
-  let stops = rest.stop
-    ? Array.isArray(rest.stop)
-      ? rest.stop
-      : [rest.stop]
-    : [];
-  stops.push("\n\nUser:");
-  stops = [...new Set(stops)];
-
-  const transformed = { ...rest, prompt: prompt, stop: stops };
-  return OpenAIV1TextCompletionSchema.parse(transformed);
-}
-
-// Takes the last chat message and uses it verbatim as the image prompt.
-function openaiToOpenaiImage(req: Request) {
-  const { body } = req;
-  const result = OpenAIV1ChatCompletionSchema.safeParse(body);
-  if (!result.success) {
-    req.log.warn(
-      { issues: result.error.issues, body },
-      "Invalid OpenAI-to-OpenAI-image request"
-    );
-    throw result.error;
-  }
-
-  const { messages } = result.data;
-  const prompt = messages.filter((m) => m.role === "user").pop()?.content;
-  if (Array.isArray(prompt)) {
-    throw new Error("Image generation prompt must be a text message.");
-  }
-
-  if (body.stream) {
-    throw new Error(
-      "Streaming is not supported for image generation requests."
-    );
-  }
-
-  // Some frontends do weird things with the prompt, like prefixing it with a
-  // character name or wrapping the entire thing in quotes. We will look for
-  // the index of "Image:" and use everything after that as the prompt.
-
-  const index = prompt?.toLowerCase().indexOf("image:");
-  if (index === -1 || !prompt) {
-    throw new Error(
-      `Start your prompt with 'Image:' followed by a description of the image you want to generate (received: ${prompt}).`
-    );
-  }
-
-  // TODO: Add some way to specify parameters via chat message
-  const transformed = {
-    model: body.model.includes("dall-e") ? body.model : "dall-e-3",
-    quality: "standard",
-    size: "1024x1024",
-    response_format: "url",
-    prompt: prompt.slice(index! + 6).trim(),
-  };
-  return OpenAIV1ImagesGenerationSchema.parse(transformed);
-}
-
-function openaiToGoogleAI(
-  req: Request
-): z.infer<typeof GoogleAIV1GenerateContentSchema> {
-  const { body } = req;
-  const result = OpenAIV1ChatCompletionSchema.safeParse({
-    ...body,
-    model: "gpt-3.5-turbo",
-  });
-  if (!result.success) {
-    req.log.warn(
-      { issues: result.error.issues, body },
-      "Invalid OpenAI-to-Google AI request"
-    );
-    throw result.error;
-  }
-
-  const { messages, ...rest } = result.data;
-  const foundNames = new Set<string>();
-  const contents = messages
-    .map((m) => {
-      const role = m.role === "assistant" ? "model" : "user";
-      // Detects character names so we can set stop sequences for them as Gemini
-      // is prone to continuing as the next character.
-      // If names are not available, we'll still try to prefix the message
-      // with generic names so we can set stops for them but they don't work
-      // as well as real names.
-      const text = flattenOpenAIMessageContent(m.content);
-      const propName = m.name?.trim();
-      const textName =
-        m.role === "system" ? "" : text.match(/^(.{0,50}?): /)?.[1]?.trim();
-      const name =
-        propName || textName || (role === "model" ? "Character" : "User");
-
-      foundNames.add(name);
-
-      // Prefixing messages with their character name seems to help avoid
-      // Gemini trying to continue as the next character, or at the very least
-      // ensures it will hit the stop sequence.  Otherwise it will start a new
-      // paragraph and switch perspectives.
-      // The response will be very likely to include this prefix so frontends
-      // will need to strip it out.
-      const textPrefix = textName ? "" : `${name}: `;
-      return {
-        parts: [{ text: textPrefix + text }],
-        role: m.role === "assistant" ? ("model" as const) : ("user" as const),
-      };
-    })
-    .reduce<GoogleAIChatMessage[]>((acc, msg) => {
-      const last = acc[acc.length - 1];
-      if (last?.role === msg.role) {
-        last.parts[0].text += "\n\n" + msg.parts[0].text;
-      } else {
-        acc.push(msg);
-      }
-      return acc;
-    }, []);
-
-  let stops = rest.stop
-    ? Array.isArray(rest.stop)
-      ? rest.stop
-      : [rest.stop]
-    : [];
-  stops.push(...Array.from(foundNames).map((name) => `\n${name}:`));
-  stops = [...new Set(stops)].slice(0, 5);
-
-  return {
-    model: "gemini-pro",
-    stream: rest.stream,
-    contents,
-    tools: [],
-    generationConfig: {
-      maxOutputTokens: rest.max_tokens,
-      stopSequences: stops,
-      topP: rest.top_p,
-      topK: 40, // openai schema doesn't have this, google ai defaults to 40
-      temperature: rest.temperature,
-    },
-    safetySettings: [
-      { category: "HARM_CATEGORY_HARASSMENT", threshold: "BLOCK_NONE" },
-      { category: "HARM_CATEGORY_HATE_SPEECH", threshold: "BLOCK_NONE" },
-      { category: "HARM_CATEGORY_SEXUALLY_EXPLICIT", threshold: "BLOCK_NONE" },
-      { category: "HARM_CATEGORY_DANGEROUS_CONTENT", threshold: "BLOCK_NONE" },
-    ],
-  };
-}
-
-export function openAIMessagesToClaudePrompt(messages: OpenAIChatMessage[]) {
-  return (
-    messages
-      .map((m) => {
-        let role: string = m.role;
-        if (role === "assistant") {
-          role = "Assistant";
-        } else if (role === "system") {
-          role = "System";
-        } else if (role === "user") {
-          role = "Human";
-        }
-        const name = m.name?.trim();
-        const content = flattenOpenAIMessageContent(m.content);
-        // https://console.anthropic.com/docs/prompt-design
-        // `name` isn't supported by Anthropic but we can still try to use it.
-        return `\n\n${role}: ${name ? `(as ${name}) ` : ""}${content}`;
-      })
-      .join("") + "\n\nAssistant:"
-  );
-}
-
-function flattenOpenAIChatMessages(messages: OpenAIChatMessage[]) {
-  // Temporary to allow experimenting with prompt strategies
-  const PROMPT_VERSION: number = 1;
-  switch (PROMPT_VERSION) {
-    case 1:
-      return (
-        messages
-          .map((m) => {
-            // Claude-style human/assistant turns
-            let role: string = m.role;
-            if (role === "assistant") {
-              role = "Assistant";
-            } else if (role === "system") {
-              role = "System";
-            } else if (role === "user") {
-              role = "User";
-            }
-            return `\n\n${role}: ${flattenOpenAIMessageContent(m.content)}`;
-          })
-          .join("") + "\n\nAssistant:"
+    // If the prompt relies on `prefix: true` for the last message, we need to
+    // convert it to a text completions request because AWS Mistral support for
+    // this feature is broken.
+    // On Mistral La Plateforme, we can't do this because they don't expose
+    // a text completions endpoint.
+    const { messages } = req.body;
+    const lastMessage = messages && messages[messages.length - 1];
+    if (lastMessage?.role === "assistant" && req.service === "aws") {
+      // enable prefix if client forgot, otherwise the template will insert an
+      // eos token which is very unlikely to be what the client wants.
+      lastMessage.prefix = true;
+      req.outboundApi = "mistral-text";
+      req.log.info(
+        "Native Mistral chat prompt relies on assistant message prefix. Converting to text completions request."
       );
-    case 2:
-      return messages
-        .map((m) => {
-          // Claude without prefixes (except system) and no Assistant priming
-          let role: string = "";
-          if (role === "system") {
-            role = "System: ";
-          }
-          return `\n\n${role}${flattenOpenAIMessageContent(m.content)}`;
-        })
-        .join("");
-    default:
-      throw new Error(`Unknown prompt version: ${PROMPT_VERSION}`);
+    }
   }
 }
-
-function flattenOpenAIMessageContent(
-  content: OpenAIChatMessage["content"]
-): string {
-  return Array.isArray(content)
-    ? content
-        .map((contentItem) => {
-          if ("text" in contentItem) return contentItem.text;
-          if ("image_url" in contentItem) return "[ Uploaded Image Omitted ]";
-        })
-        .join("\n")
-    : content;
-}

src/proxy/middleware/request/preprocessors/validate-context-size.ts

@@ -6,8 +6,9 @@ import { RequestPreprocessor } from "../index";
 
 const CLAUDE_MAX_CONTEXT = config.maxContextTokensAnthropic;
 const OPENAI_MAX_CONTEXT = config.maxContextTokensOpenAI;
-const GOOGLE_AI_MAX_CONTEXT = 32000;
-const MISTRAL_AI_MAX_CONTENT = 32768;
+// todo: make configurable
+const GOOGLE_AI_MAX_CONTEXT = 2048000;
+const MISTRAL_AI_MAX_CONTENT = 131072;
 
 /**
  * Assigns `req.promptTokens` and `req.outputTokens` based on the request body
@@ -29,14 +30,17 @@ export const validateContextSize: RequestPreprocessor = async (req) => {
     case "openai-text":
       proxyMax = OPENAI_MAX_CONTEXT;
       break;
-    case "anthropic":
+    case "anthropic-chat":
+    case "anthropic-text":
       proxyMax = CLAUDE_MAX_CONTEXT;
       break;
     case "google-ai":
       proxyMax = GOOGLE_AI_MAX_CONTEXT;
       break;
     case "mistral-ai":
+    case "mistral-text":
       proxyMax = MISTRAL_AI_MAX_CONTENT;
+      break;
     case "openai-image":
       return;
     default:
@@ -44,15 +48,32 @@ export const validateContextSize: RequestPreprocessor = async (req) => {
   }
   proxyMax ||= Number.MAX_SAFE_INTEGER;
 
+  if (req.user?.type === "special") {
+    req.log.debug("Special user, not enforcing proxy context limit.");
+    proxyMax = Number.MAX_SAFE_INTEGER;
+  }
+
   let modelMax: number;
   if (model.match(/gpt-3.5-turbo-16k/)) {
     modelMax = 16384;
-  } else if (model.match(/gpt-4-1106(-preview)?/)) {
+  } else if (model.match(/^gpt-4o/)) {
+    modelMax = 128000;
+  } else if (model.match(/^chatgpt-4o/)) {
+    modelMax = 128000;
+  } else if (model.match(/gpt-4-turbo(-\d{4}-\d{2}-\d{2})?$/)) {
+    modelMax = 131072;
+  } else if (model.match(/gpt-4-turbo(-preview)?$/)) {
+    modelMax = 131072;
+  } else if (model.match(/gpt-4-(0125|1106)(-preview)?$/)) {
     modelMax = 131072;
   } else if (model.match(/^gpt-4(-\d{4})?-vision(-preview)?$/)) {
     modelMax = 131072;
+  } else if (model.match(/^o1-mini(-\d{4}-\d{2}-\d{2})?$/)) {
+    modelMax = 128000;
+  } else if (model.match(/^o1(-preview)?(-\d{4}-\d{2}-\d{2})?$/)) {
+    modelMax = 128000;
   } else if (model.match(/gpt-3.5-turbo/)) {
-    modelMax = 4096;
+    modelMax = 16384;
   } else if (model.match(/gpt-4-32k/)) {
     modelMax = 32768;
   } else if (model.match(/gpt-4/)) {
@@ -65,13 +86,21 @@ export const validateContextSize: RequestPreprocessor = async (req) => {
     modelMax = 100000;
   } else if (model.match(/^claude-2/)) {
     modelMax = 200000;
-  } else if (model.match(/^gemini-\d{3}$/)) {
-    modelMax = GOOGLE_AI_MAX_CONTEXT;
-  } else if (model.match(/^mistral-(tiny|small|medium)$/)) {
-    modelMax = MISTRAL_AI_MAX_CONTENT;
+  } else if (model.match(/^claude-3/)) {
+    modelMax = 200000;
+  } else if (model.match(/^gemini-/)) {
+    modelMax = 1024000;
+  } else if (model.match(/^anthropic\.claude-3/)) {
+    modelMax = 200000;
+  } else if (model.match(/^anthropic\.claude-v2:\d/)) {
+    modelMax = 200000;
   } else if (model.match(/^anthropic\.claude/)) {
-    // Not sure if AWS Claude has the same context limit as Anthropic Claude.
     modelMax = 100000;
+  } else if (model.match(/tral/)) {
+    // catches mistral, mixtral, codestral, mathstral, etc. mistral models have
+    // no name convention and wildly different context windows so this is a
+    // catch-all
+    modelMax = MISTRAL_AI_MAX_CONTENT;
   } else {
     req.log.warn({ model }, "Unknown model, using 200k token limit.");
     modelMax = 200000;

src/proxy/middleware/request/preprocessors/validate-model-family.ts

@@ -1,14 +1,16 @@
-import { HPMRequestCallback } from "../index";
 import { config } from "../../../../config";
 import { ForbiddenError } from "../../../../shared/errors";
 import { getModelFamilyForRequest } from "../../../../shared/models";
+import { RequestPreprocessor } from "../index";
 
 /**
  * Ensures the selected model family is enabled by the proxy configuration.
- **/
-export const checkModelFamily: HPMRequestCallback = (_proxyReq, req, res) => {
+ */
+export const validateModelFamily: RequestPreprocessor = (req) => {
   const family = getModelFamilyForRequest(req);
   if (!config.allowedModelFamilies.includes(family)) {
-    throw new ForbiddenError(`Model family '${family}' is not enabled on this proxy`);
+    throw new ForbiddenError(
+      `Model family '${family}' is not enabled on this proxy`
+    );
   }
 };

src/proxy/middleware/request/preprocessors/validate-vision.ts

@@ -0,0 +1,44 @@
+import { config } from "../../../../config";
+import { assertNever } from "../../../../shared/utils";
+import { RequestPreprocessor } from "../index";
+import { containsImageContent as containsImageContentOpenAI } from "../../../../shared/api-schemas/openai";
+import { containsImageContent as containsImageContentAnthropic } from "../../../../shared/api-schemas/anthropic";
+import { ForbiddenError } from "../../../../shared/errors";
+
+/**
+ * Rejects prompts containing images if multimodal prompts are disabled.
+ */
+export const validateVision: RequestPreprocessor = async (req) => {
+  if (req.service === undefined) {
+    throw new Error("Request service must be set before validateVision");
+  }
+
+  if (req.user?.type === "special") return;
+  if (config.allowedVisionServices.includes(req.service)) return;
+
+  // vision not allowed for req's service, block prompts with images
+  let hasImage = false;
+  switch (req.outboundApi) {
+    case "openai":
+      hasImage = containsImageContentOpenAI(req.body.messages);
+      break;
+    case "anthropic-chat":
+      hasImage = containsImageContentAnthropic(req.body.messages);
+      break;
+    case "anthropic-text":
+    case "google-ai":
+    case "mistral-ai":
+    case "mistral-text":
+    case "openai-image":
+    case "openai-text":
+      return;
+    default:
+      assertNever(req.outboundApi);
+  }
+
+  if (hasImage) {
+    throw new ForbiddenError(
+      "Prompts containing images are not permitted. Disable 'Send Inline Images' in your client and try again."
+    );
+  }
+};

src/proxy/middleware/request/proxy-middleware-factory.ts

@@ -0,0 +1,135 @@
+import { Request, Response } from "express";
+import http from "http";
+import ProxyServer from "http-proxy";
+import { Readable } from "stream";
+import {
+  createProxyMiddleware,
+  Options,
+  debugProxyErrorsPlugin,
+  proxyEventsPlugin,
+} from "http-proxy-middleware";
+import { ProxyReqMutator, stripHeaders } from "./index";
+import { createOnProxyResHandler, ProxyResHandlerWithBody } from "../response";
+import { createQueueMiddleware } from "../../queue";
+import { getHttpAgents } from "../../../shared/network";
+import { classifyErrorAndSend } from "../common";
+
+/**
+ * Options for the `createQueuedProxyMiddleware` factory function.
+ */
+type ProxyMiddlewareFactoryOptions = {
+  /**
+   * Functions which receive a ProxyReqManager and can modify the request before
+   * it is proxied. The modifications will be automatically reverted if the
+   * request needs to be returned to the queue.
+   */
+  mutations?: ProxyReqMutator[];
+  /**
+   * The target URL to proxy requests to. This can be a string or a function
+   * which accepts the request and returns a string.
+   */
+  target: string | Options<Request>["router"];
+  /**
+   * A function which receives the proxy response and the JSON-decoded request
+   * body. Only fired for non-streaming responses; streaming responses are
+   * handled in `handle-streaming-response.ts`.
+   */
+  blockingResponseHandler?: ProxyResHandlerWithBody;
+};
+
+/**
+ * Returns a middleware function that accepts incoming requests and places them
+ * into the request queue. When the request is dequeued, it is proxied to the
+ * target URL using the given options and middleware. Non-streaming responses
+ * are handled by the given `blockingResponseHandler`.
+ */
+export function createQueuedProxyMiddleware({
+  target,
+  mutations,
+  blockingResponseHandler,
+}: ProxyMiddlewareFactoryOptions) {
+  const hpmTarget = typeof target === "string" ? target : "https://setbyrouter";
+  const hpmRouter = typeof target === "function" ? target : undefined;
+
+  const [httpAgent, httpsAgent] = getHttpAgents();
+  const agent = hpmTarget.startsWith("http:") ? httpAgent : httpsAgent;
+
+  const proxyMiddleware = createProxyMiddleware<Request, Response>({
+    target: hpmTarget,
+    router: hpmRouter,
+    agent,
+    changeOrigin: true,
+    toProxy: true,
+    selfHandleResponse: typeof blockingResponseHandler === "function",
+    // Disable HPM logger plugin (requires re-adding the other default plugins).
+    // Contrary to name, debugProxyErrorsPlugin is not just for debugging and
+    // fixes several error handling/connection close issues in http-proxy core.
+    ejectPlugins: true,
+    // Inferred (via Options<express.Request>) as Plugin<express.Request>, but
+    // the default plugins only allow http.IncomingMessage for TReq. They are
+    // compatible with express.Request, so we can use them. `Plugin` type is not
+    // exported for some reason.
+    plugins: [
+      debugProxyErrorsPlugin,
+      pinoLoggerPlugin,
+      proxyEventsPlugin,
+    ] as any,
+    on: {
+      proxyRes: createOnProxyResHandler(
+        blockingResponseHandler ? [blockingResponseHandler] : []
+      ),
+      error: classifyErrorAndSend,
+    },
+    buffer: ((req: Request) => {
+      // This is a hack/monkey patch and is not part of the official
+      // http-proxy-middleware package. See patches/http-proxy+1.18.1.patch.
+      let payload = req.body;
+      if (typeof payload === "string") {
+        payload = Buffer.from(payload);
+      }
+      const stream = new Readable();
+      stream.push(payload);
+      stream.push(null);
+      return stream;
+    }) as any,
+  });
+
+  return createQueueMiddleware({
+    mutations: [stripHeaders, ...(mutations ?? [])],
+    proxyMiddleware,
+  });
+}
+
+type ProxiedResponse = http.IncomingMessage & Response & any;
+function pinoLoggerPlugin(proxyServer: ProxyServer<Request>) {
+  proxyServer.on("error", (err, req, res, target) => {
+    req.log.error(
+      { originalUrl: req.originalUrl, targetUrl: String(target), err },
+      "Error occurred while proxying request to target"
+    );
+  });
+  proxyServer.on("proxyReq", (proxyReq, req) => {
+    const { protocol, host, path } = proxyReq;
+    req.log.info(
+      {
+        from: req.originalUrl,
+        to: `${protocol}//${host}${path}`,
+      },
+      "Sending request to upstream API..."
+    );
+  });
+  proxyServer.on("proxyRes", (proxyRes: ProxiedResponse, req, _res) => {
+    const { protocol, host, path } = proxyRes.req;
+    req.log.info(
+      {
+        target: `${protocol}//${host}${path}`,
+        status: proxyRes.statusCode,
+        contentType: proxyRes.headers["content-type"],
+        contentEncoding: proxyRes.headers["content-encoding"],
+        contentLength: proxyRes.headers["content-length"],
+        transferEncoding: proxyRes.headers["transfer-encoding"],
+      },
+      "Got response from upstream API."
+    );
+  });
+}

src/proxy/middleware/request/proxy-req-manager.ts

@@ -0,0 +1,112 @@
+import { Request } from "express";
+import { Key } from "../../../shared/key-management";
+import { assertNever } from "../../../shared/utils";
+
+/**
+ * Represents a change to the request that will be reverted if the request
+ * fails.
+ */
+interface ProxyReqMutation {
+  target: "header" | "path" | "body" | "api-key" | "signed-request";
+  key?: string;
+  originalValue: any | undefined;
+}
+
+/**
+ * Manages a request's headers, body, and path, allowing them to be modified
+ * before the request is proxied and automatically reverted if the request
+ * needs to be retried.
+ */
+export class ProxyReqManager {
+  private req: Request;
+  private mutations: ProxyReqMutation[] = [];
+
+  /**
+   * A read-only proxy of the request object. Avoid changing any properties
+   * here as they will persist across retries.
+   */
+  public readonly request: Readonly<Request>;
+
+  constructor(req: Request) {
+    this.req = req;
+
+    this.request = new Proxy(req, {
+      get: (target, prop) => {
+        if (typeof prop === "string") return target[prop as keyof Request];
+        return undefined;
+      },
+    });
+  }
+
+  setHeader(name: string, newValue: string): void {
+    const originalValue = this.req.get(name);
+    this.mutations.push({ target: "header", key: name, originalValue });
+    this.req.headers[name.toLowerCase()] = newValue;
+  }
+
+  removeHeader(name: string): void {
+    const originalValue = this.req.get(name);
+    this.mutations.push({ target: "header", key: name, originalValue });
+    delete this.req.headers[name.toLowerCase()];
+  }
+
+  setBody(newBody: any): void {
+    const originalValue = this.req.body;
+    this.mutations.push({ target: "body", key: "body", originalValue });
+    this.req.body = newBody;
+  }
+
+  setKey(newKey: Key): void {
+    const originalValue = this.req.key;
+    this.mutations.push({ target: "api-key", key: "key", originalValue });
+    this.req.key = newKey;
+  }
+
+  setPath(newPath: string): void {
+    const originalValue = this.req.path;
+    this.mutations.push({ target: "path", key: "path", originalValue });
+    this.req.url = newPath;
+  }
+
+  setSignedRequest(newSignedRequest: typeof this.req.signedRequest): void {
+    const originalValue = this.req.signedRequest;
+    this.mutations.push({ target: "signed-request", key: "signedRequest", originalValue });
+    this.req.signedRequest = newSignedRequest;
+  }
+
+  hasChanged(): boolean {
+    return this.mutations.length > 0;
+  }
+
+  revert(): void {
+    for (const mutation of this.mutations.reverse()) {
+      switch (mutation.target) {
+        case "header":
+          if (mutation.originalValue === undefined) {
+            delete this.req.headers[mutation.key!.toLowerCase()];
+            continue;
+          } else {
+            this.req.headers[mutation.key!.toLowerCase()] =
+              mutation.originalValue;
+          }
+          break;
+        case "path":
+          this.req.url = mutation.originalValue;
+          break;
+        case "body":
+          this.req.body = mutation.originalValue;
+          break;
+        case "api-key":
+          // We don't reset the key here because it's not a property of the
+          // inbound request, so we'd only ever be reverting it to null.
+          break;
+        case "signed-request":
+          this.req.signedRequest = mutation.originalValue;
+          break;
+        default:
+          assertNever(mutation.target);
+      }
+    }
+    this.mutations = [];
+  }
+}

src/proxy/middleware/response/compression.ts

@@ -0,0 +1,36 @@
+import util from "util";
+import zlib from "zlib";
+import { PassThrough } from "stream";
+
+const BUFFER_DECODER_MAP = {
+  gzip: util.promisify(zlib.gunzip),
+  deflate: util.promisify(zlib.inflate),
+  br: util.promisify(zlib.brotliDecompress),
+  text: (data: Buffer) => data,
+};
+
+const STREAM_DECODER_MAP = {
+  gzip: zlib.createGunzip,
+  deflate: zlib.createInflate,
+  br: zlib.createBrotliDecompress,
+  text: () => new PassThrough(),
+};
+
+type SupportedContentEncoding = keyof typeof BUFFER_DECODER_MAP;
+const isSupportedContentEncoding = (
+  encoding: string
+): encoding is SupportedContentEncoding => encoding in BUFFER_DECODER_MAP;
+
+export async function decompressBuffer(buf: Buffer, encoding: string = "text") {
+  if (isSupportedContentEncoding(encoding)) {
+    return (await BUFFER_DECODER_MAP[encoding](buf)).toString();
+  }
+  throw new Error(`Unsupported content-encoding: ${encoding}`);
+}
+
+export function getStreamDecompressor(encoding: string = "text") {
+  if (isSupportedContentEncoding(encoding)) {
+    return STREAM_DECODER_MAP[encoding]();
+  }
+  throw new Error(`Unsupported content-encoding: ${encoding}`);
+}

src/proxy/middleware/response/error-generator.ts

@@ -0,0 +1,405 @@
+import express from "express";
+import { APIFormat } from "../../../shared/key-management";
+import { assertNever } from "../../../shared/utils";
+import { initializeSseStream } from "../../../shared/streaming";
+import http from "http";
+
+/**
+ * Returns a Markdown-formatted message that renders semi-nicely in most chat
+ * frontends. For example:
+ *
+ * **Proxy error (HTTP 404 Not Found)**
+ * The proxy encountered an error while trying to send your prompt to the upstream service. Further technical details are provided below.
+ * ***
+ * *The requested Claude model might not exist, or the key might not be provisioned for it.*
+ * ```
+ * {
+ *  "type": "error",
+ *  "error": {
+ *    "type": "not_found_error",
+ *    "message": "model: some-invalid-model-id",
+ *   },
+ *  "proxy_note": "The requested Claude model might not exist, or the key might not be provisioned for it."
+ * }
+ * ```
+ */
+function getMessageContent(params: {
+  title: string;
+  message: string;
+  obj?: Record<string, any>;
+}) {
+  const { title, message, obj } = params;
+  const note = obj?.proxy_note || obj?.error?.message || "";
+  const header = `### **${title}**`;
+  const friendlyMessage = note ? `${message}\n\n----\n\n*${note}*` : message;
+
+  const serializedObj = obj
+    ? ["```", JSON.stringify(obj, null, 2), "```"].join("\n")
+    : "";
+
+  const { stack } = JSON.parse(JSON.stringify(obj ?? {}));
+  let prettyTrace = "";
+  if (stack && obj) {
+    prettyTrace = [
+      "Include this trace when reporting an issue.",
+      "```",
+      stack,
+      "```",
+    ].join("\n");
+    delete obj.stack;
+  }
+
+  return [
+    header,
+    friendlyMessage,
+    serializedObj,
+    prettyTrace,
+    "<!-- oai-proxy-error -->",
+  ].join("\n\n");
+}
+
+type ErrorGeneratorOptions = {
+  format: APIFormat | "unknown";
+  title: string;
+  message: string;
+  obj?: Record<string, any>;
+  reqId: string | number | object;
+  model?: string;
+  statusCode?: number;
+};
+
+/**
+ * Very crude inference of the request format based on the request body. Don't
+ * rely on this to be very accurate.
+ */
+function tryInferFormat(body: any): APIFormat | "unknown" {
+  if (typeof body !== "object" || !body.model) {
+    return "unknown";
+  }
+
+  if (body.model.includes("gpt")) {
+    return "openai";
+  }
+
+  if (body.model.includes("mistral")) {
+    return "mistral-ai";
+  }
+
+  if (body.model.includes("claude")) {
+    return body.messages?.length ? "anthropic-chat" : "anthropic-text";
+  }
+
+  if (body.model.includes("gemini")) {
+    return "google-ai";
+  }
+
+  return "unknown";
+}
+
+/**
+ * Redacts the hostname from the error message if it contains a DNS resolution
+ * error. This is to avoid leaking upstream hostnames on DNS resolution errors,
+ * as those may contain sensitive information about the proxy's configuration.
+ */
+function redactHostname(options: ErrorGeneratorOptions): ErrorGeneratorOptions {
+  if (!options.message.includes("getaddrinfo")) return options;
+
+  const redacted = { ...options };
+  redacted.message = "Could not resolve hostname";
+
+  if (typeof redacted.obj?.error === "object") {
+    redacted.obj = {
+      ...redacted.obj,
+      error: { message: "Could not resolve hostname" },
+    };
+  }
+
+  return redacted;
+}
+
+/**
+ * Generates an appropriately-formatted error response and sends it to the
+ * client over their requested transport (blocking or SSE stream).
+ */
+export function sendErrorToClient(params: {
+  options: ErrorGeneratorOptions;
+  req: express.Request;
+  res: express.Response;
+}) {
+  const { req, res } = params;
+  const options = redactHostname(params.options);
+  const { statusCode, message, title, obj: details } = options;
+
+  // Since we want to send the error in a format the client understands, we
+  // need to know the request format. `setApiFormat` might not have been called
+  // yet, so we'll try to infer it from the request body.
+  const format =
+    options.format === "unknown" ? tryInferFormat(req.body) : options.format;
+  if (format === "unknown") {
+    // Early middleware error (auth, rate limit) so we can only send something
+    // generic.
+    const code = statusCode || 400;
+    const hasDetails = details && Object.keys(details).length > 0;
+    return res.status(code).json({
+      error: {
+        message,
+        type: http.STATUS_CODES[code]!.replace(/\s+/g, "_").toLowerCase(),
+      },
+      ...(hasDetails ? { details } : {}),
+    });
+  }
+
+  // Cannot modify headers if client opted into streaming and made it into the
+  // proxy request queue, because that immediately starts an SSE stream.
+  if (!res.headersSent) {
+    res.setHeader("x-oai-proxy-error", title);
+    res.setHeader("x-oai-proxy-error-status", statusCode || 500);
+  }
+
+  // By this point, we know the request format. To get the error to display in
+  // chat clients' UIs, we'll send it as a 200 response as a spoofed completion
+  // from the language model. Depending on whether the client is streaming, we
+  // will either send an SSE event or a JSON response.
+  const isStreaming = req.isStreaming || String(req.body.stream) === "true";
+  if (isStreaming) {
+    // User can have opted into streaming but not made it into the queue yet,
+    // in which case the stream must be started first.
+    if (!res.headersSent) {
+      initializeSseStream(res);
+    }
+    res.write(buildSpoofedSSE({ ...options, format }));
+    res.write(`data: [DONE]\n\n`);
+    res.end();
+  } else {
+    res.status(200).json(buildSpoofedCompletion({ ...options, format }));
+  }
+}
+
+/**
+ * Returns a non-streaming completion object that looks like it came from the
+ * service that the request is being proxied to. Used to send error messages to
+ * the client and have them look like normal responses, for clients with poor
+ * error handling.
+ */
+export function buildSpoofedCompletion({
+  format,
+  title,
+  message,
+  obj,
+  reqId,
+  model = "unknown",
+}: ErrorGeneratorOptions & { format: Exclude<APIFormat, "unknown"> }) {
+  const id = String(reqId);
+  const content = getMessageContent({ title, message, obj });
+
+  switch (format) {
+    case "openai":
+    case "mistral-ai":
+      return {
+        id: "error-" + id,
+        object: "chat.completion",
+        created: Date.now(),
+        model,
+        usage: { prompt_tokens: 0, completion_tokens: 0, total_tokens: 0 },
+        choices: [
+          {
+            message: { role: "assistant", content },
+            finish_reason: title,
+            index: 0,
+          },
+        ],
+      };
+    case "mistral-text":
+      return {
+        outputs: [{ text: content, stop_reason: title }],
+        model,
+      };
+    case "openai-text":
+      return {
+        id: "error-" + id,
+        object: "text_completion",
+        created: Date.now(),
+        model,
+        usage: { prompt_tokens: 0, completion_tokens: 0, total_tokens: 0 },
+        choices: [
+          { text: content, index: 0, logprobs: null, finish_reason: title },
+        ],
+      };
+    case "anthropic-text":
+      return {
+        id: "error-" + id,
+        type: "completion",
+        completion: content,
+        stop_reason: title,
+        stop: null,
+        model,
+      };
+    case "anthropic-chat":
+      return {
+        id: "error-" + id,
+        type: "message",
+        role: "assistant",
+        content: [{ type: "text", text: content }],
+        model,
+        stop_reason: title,
+        stop_sequence: null,
+      };
+    case "google-ai":
+      return {
+        candidates: [
+          {
+            content: { parts: [{ text: content }], role: "model" },
+            finishReason: title,
+            index: 0,
+            tokenCount: null,
+            safetyRatings: [],
+          },
+        ],
+      };
+    case "openai-image":
+      return obj;
+    default:
+      assertNever(format);
+  }
+}
+
+/**
+ * Returns an SSE message that looks like a completion event for the service
+ * that the request is being proxied to. Used to send error messages to the
+ * client in the middle of a streaming request.
+ */
+export function buildSpoofedSSE({
+  format,
+  title,
+  message,
+  obj,
+  reqId,
+  model = "unknown",
+}: ErrorGeneratorOptions & { format: Exclude<APIFormat, "unknown"> }) {
+  const id = String(reqId);
+  const content = getMessageContent({ title, message, obj });
+
+  let event;
+
+  switch (format) {
+    case "openai":
+    case "mistral-ai":
+      event = {
+        id: "chatcmpl-" + id,
+        object: "chat.completion.chunk",
+        created: Date.now(),
+        model,
+        choices: [{ delta: { content }, index: 0, finish_reason: title }],
+      };
+      break;
+    case "mistral-text":
+      event = {
+        outputs: [{ text: content, stop_reason: title }],
+      };
+      break;
+    case "openai-text":
+      event = {
+        id: "cmpl-" + id,
+        object: "text_completion",
+        created: Date.now(),
+        choices: [
+          { text: content, index: 0, logprobs: null, finish_reason: title },
+        ],
+        model,
+      };
+      break;
+    case "anthropic-text":
+      event = {
+        completion: content,
+        stop_reason: title,
+        truncated: false,
+        stop: null,
+        model,
+        log_id: "proxy-req-" + id,
+      };
+      break;
+    case "anthropic-chat":
+      event = {
+        type: "content_block_delta",
+        index: 0,
+        delta: { type: "text_delta", text: content },
+      };
+      break;
+    case "google-ai":
+      // TODO: google ai supports two streaming transports, SSE and JSON.
+      // we currently only support SSE.
+      // return JSON.stringify({
+      event = {
+        candidates: [
+          {
+            content: { parts: [{ text: content }], role: "model" },
+            finishReason: title,
+            index: 0,
+            tokenCount: null,
+            safetyRatings: [],
+          },
+        ],
+      };
+      break;
+    case "openai-image":
+      return JSON.stringify(obj);
+    default:
+      assertNever(format);
+  }
+
+  if (format === "anthropic-text") {
+    return (
+      ["event: completion", `data: ${JSON.stringify(event)}`].join("\n") +
+      "\n\n"
+    );
+  }
+
+  // ugh.
+  if (format === "anthropic-chat") {
+    return (
+      [
+        [
+          "event: message_start",
+          `data: ${JSON.stringify({
+            type: "message_start",
+            message: {
+              id: "error-" + id,
+              type: "message",
+              role: "assistant",
+              content: [],
+              model,
+            },
+          })}`,
+        ].join("\n"),
+        [
+          "event: content_block_start",
+          `data: ${JSON.stringify({
+            type: "content_block_start",
+            index: 0,
+            content_block: { type: "text", text: "" },
+          })}`,
+        ].join("\n"),
+        ["event: content_block_delta", `data: ${JSON.stringify(event)}`].join(
+          "\n"
+        ),
+        [
+          "event: content_block_stop",
+          `data: ${JSON.stringify({ type: "content_block_stop", index: 0 })}`,
+        ].join("\n"),
+        [
+          "event: message_delta",
+          `data: ${JSON.stringify({
+            type: "message_delta",
+            delta: { stop_reason: title, stop_sequence: null, usage: null },
+          })}`,
+        ],
+        [
+          "event: message_stop",
+          `data: ${JSON.stringify({ type: "message_stop" })}`,
+        ].join("\n"),
+      ].join("\n\n") + "\n\n"
+    );
+  }
+
+  return `data: ${JSON.stringify(event)}\n\n`;
+}

src/proxy/middleware/response/handle-blocking-response.ts

@@ -0,0 +1,70 @@
+import { sendProxyError } from "../common";
+import type { RawResponseBodyHandler } from "./index";
+import { decompressBuffer } from "./compression";
+
+/**
+ * Handles the response from the upstream service and decodes the body if
+ * necessary. If the response is JSON, it will be parsed and returned as an
+ * object. Otherwise, it will be returned as a string. Does not handle streaming
+ * responses.
+ * @throws {Error} Unsupported content-encoding or invalid application/json body
+ */
+export const handleBlockingResponse: RawResponseBodyHandler = async (
+  proxyRes,
+  req,
+  res
+) => {
+  if (req.isStreaming) {
+    const err = new Error(
+      "handleBlockingResponse called for a streaming request."
+    );
+    req.log.error({ stack: err.stack, api: req.inboundApi }, err.message);
+    throw err;
+  }
+
+  return new Promise((resolve, reject) => {
+    let chunks: Buffer[] = [];
+    proxyRes.on("data", (chunk) => chunks.push(chunk));
+    proxyRes.on("end", async () => {
+      const contentEncoding = proxyRes.headers["content-encoding"];
+      const contentType = proxyRes.headers["content-type"];
+      let body: string | Buffer = Buffer.concat(chunks);
+      const rejectWithMessage = function (msg: string, err: Error) {
+        const error = `${msg} (${err.message})`;
+        req.log.warn(
+          { msg: error, stack: err.stack },
+          "Error in blocking response handler"
+        );
+        sendProxyError(req, res, 500, "Internal Server Error", { error });
+        return reject(error);
+      };
+
+      try {
+        body = await decompressBuffer(body, contentEncoding);
+      } catch (e) {
+        return rejectWithMessage(`Could not decode response body`, e);
+      }
+
+      try {
+        return resolve(tryParseAsJson(body, contentType));
+      } catch (e) {
+        return rejectWithMessage("API responded with invalid JSON", e);
+      }
+    });
+  });
+};
+
+function tryParseAsJson(body: string, contentType?: string) {
+  // If the response is declared as JSON, it must parse or we will throw
+  if (contentType?.includes("application/json")) {
+    return JSON.parse(body);
+  }
+  // If it's not declared as JSON, some APIs we'll try to parse it as JSON
+  // anyway since some APIs return the wrong content-type header in some cases.
+  // If it fails to parse, we'll just return the raw body without throwing.
+  try {
+    return JSON.parse(body);
+  } catch (e) {
+    return body;
+  }
+}

src/proxy/middleware/response/handle-streamed-response.ts

@@ -1,67 +1,95 @@
-import { pipeline } from "stream";
+import express from "express";
+import { pipeline, Readable, Transform } from "stream";
+import { StringDecoder } from "string_decoder";
 import { promisify } from "util";
+import type { logger } from "../../../logger";
+import { BadRequestError, RetryableError } from "../../../shared/errors";
+import { APIFormat, keyPool } from "../../../shared/key-management";
 import {
-  makeCompletionSSE,
   copySseResponseHeaders,
   initializeSseStream,
 } from "../../../shared/streaming";
-import { enqueue } from "../../queue";
-import { decodeResponseBody, RawResponseBodyHandler, RetryableError } from ".";
-import { SSEStreamAdapter } from "./streaming/sse-stream-adapter";
-import { SSEMessageTransformer } from "./streaming/sse-message-transformer";
+import { reenqueueRequest } from "../../queue";
+import type { RawResponseBodyHandler } from ".";
+import { handleBlockingResponse } from "./handle-blocking-response";
+import { buildSpoofedSSE, sendErrorToClient } from "./error-generator";
+import { getAwsEventStreamDecoder } from "./streaming/aws-event-stream-decoder";
 import { EventAggregator } from "./streaming/event-aggregator";
-import { keyPool } from "../../../shared/key-management";
+import { SSEMessageTransformer } from "./streaming/sse-message-transformer";
+import { SSEStreamAdapter } from "./streaming/sse-stream-adapter";
+import { getStreamDecompressor } from "./compression";
 
 const pipelineAsync = promisify(pipeline);
 
 /**
- * Consume the SSE stream and forward events to the client. Once the stream is
- * stream is closed, resolve with the full response body so that subsequent
- * middleware can work with it.
+ * `handleStreamedResponse` consumes a streamed response from the upstream API,
+ * decodes chunk-by-chunk into a stream of events, transforms those events into
+ * the client's requested format, and forwards the result to the client.
  *
- * Typically we would only need of the raw response handlers to execute, but
- * in the event a streamed request results in a non-200 response, we need to
- * fall back to the non-streaming response handler so that the error handler
- * can inspect the error response.
+ * After the entire stream has been consumed, it resolves with the full response
+ * body so that subsequent middleware in the chain can process it as if it were
+ * a non-streaming response (to count output tokens, track usage, etc).
+ *
+ * In the event of an error, the request's streaming flag is unset and the
+ * request is bounced back to the non-streaming response handler. If the error
+ * is retryable, that handler will re-enqueue the request and also reset the
+ * streaming flag. Unfortunately the streaming flag is set and unset in multiple
+ * places, so it's hard to keep track of.
  */
 export const handleStreamedResponse: RawResponseBodyHandler = async (
   proxyRes,
   req,
   res
 ) => {
-  const { hash } = req.key!;
+  const { headers, statusCode } = proxyRes;
   if (!req.isStreaming) {
     throw new Error("handleStreamedResponse called for non-streaming request.");
   }
 
-  if (proxyRes.statusCode! > 201) {
+  if (statusCode! > 201) {
     req.isStreaming = false;
     req.log.warn(
-      { statusCode: proxyRes.statusCode, key: hash },
+      { statusCode },
       `Streaming request returned error status code. Falling back to non-streaming response handler.`
     );
-    return decodeResponseBody(proxyRes, req, res);
+    return handleBlockingResponse(proxyRes, req, res);
   }
 
-  req.log.debug(
-    { headers: proxyRes.headers, key: hash },
-    `Starting to proxy SSE stream.`
-  );
+  req.log.debug({ headers }, `Starting to proxy SSE stream.`);
 
-  // Users waiting in the queue already have a SSE connection open for the
-  // heartbeat, so we can't always send the stream headers.
+  // Typically, streaming will have already been initialized by the request
+  // queue to send heartbeat pings.
   if (!res.headersSent) {
     copySseResponseHeaders(proxyRes, res);
     initializeSseStream(res);
   }
 
   const prefersNativeEvents = req.inboundApi === req.outboundApi;
-  const contentType = proxyRes.headers["content-type"];
+  const streamOptions = {
+    contentType: headers["content-type"],
+    api: req.outboundApi,
+    logger: req.log,
+  };
 
-  const adapter = new SSEStreamAdapter({ contentType, api: req.outboundApi });
-  const aggregator = new EventAggregator({ format: req.outboundApi });
+  // While the request is streaming, aggregator collects all events so that we
+  // can compile them into a single response object and publish that to the
+  // remaining middleware. Because we have an OpenAI transformer for every
+  // supported format, EventAggregator always consumes OpenAI events so that we
+  // only have to write one aggregator (OpenAI input) for each output format.
+  const aggregator = new EventAggregator(req);
+
+  const decompressor = getStreamDecompressor(headers["content-encoding"]);
+  // Decoder reads from the response bytes to produce a stream of plaintext.
+  const decoder = getDecoder({ ...streamOptions, input: proxyRes });
+  // Adapter consumes the decoded text and produces server-sent events so we
+  // have a standard event format for the client and to translate between API
+  // message formats.
+  const adapter = new SSEStreamAdapter(streamOptions);
+  // Transformer converts server-sent events from one vendor's API message
+  // format to another.
   const transformer = new SSEMessageTransformer({
-    inputFormat: req.outboundApi,
+    inputFormat: req.outboundApi, // The format of the upstream service's events
+    outputFormat: req.inboundApi, // The format the client requested
     inputApiVersion: String(req.headers["anthropic-version"]),
     logger: req.log,
     requestId: String(req.id),
@@ -76,23 +104,33 @@ export const handleStreamedResponse: RawResponseBodyHandler = async (
     });
 
   try {
-    await pipelineAsync(proxyRes, adapter, transformer);
-    req.log.debug({ key: hash }, `Finished proxying SSE stream.`);
+    await Promise.race([
+      handleAbortedStream(req, res),
+      pipelineAsync(proxyRes, decompressor, decoder, adapter, transformer),
+    ]);
+    req.log.debug(`Finished proxying SSE stream.`);
     res.end();
     return aggregator.getFinalResponse();
   } catch (err) {
     if (err instanceof RetryableError) {
       keyPool.markRateLimited(req.key!);
-      req.log.warn(
-        { key: req.key!.hash, retryCount: req.retryCount },
-        `Re-enqueueing request due to retryable error during streaming response.`
-      );
-      req.retryCount++;
-      await enqueue(req);
+      await reenqueueRequest(req);
+    } else if (err instanceof BadRequestError) {
+      sendErrorToClient({
+        req,
+        res,
+        options: {
+          format: req.inboundApi,
+          title: "Proxy streaming error (Bad Request)",
+          message: `The API returned an error while streaming your request. Your prompt might not be formatted correctly.\n\n*${err.message}*`,
+          reqId: req.id,
+          model: req.body?.model,
+        },
+      });
     } else {
       const { message, stack, lastEvent } = err;
-      const eventText = JSON.stringify(lastEvent, null, 2) ?? "undefined"
-      const errorEvent = makeCompletionSSE({
+      const eventText = JSON.stringify(lastEvent, null, 2) ?? "undefined";
+      const errorEvent = buildSpoofedSSE({
         format: req.inboundApi,
         title: "Proxy stream error",
         message: "An unexpected error occurred while streaming the response.",
@@ -104,6 +142,53 @@ export const handleStreamedResponse: RawResponseBodyHandler = async (
       res.write(`data: [DONE]\n\n`);
       res.end();
     }
-    throw err;
+
+    // At this point the response is closed. If the request resulted in any
+    // tokens being consumed (suggesting a mid-stream error), we will resolve
+    // and continue the middleware chain so tokens can be counted.
+    if (aggregator.hasEvents()) {
+      return aggregator.getFinalResponse();
+    } else {
+      // If there is nothing, then this was a completely failed prompt that
+      // will not have billed any tokens. Throw to stop the middleware chain.
+      throw err;
+    }
   }
 };
+
+function handleAbortedStream(req: express.Request, res: express.Response) {
+  return new Promise<void>((resolve) =>
+    res.on("close", () => {
+      if (!res.writableEnded) {
+        req.log.info("Client prematurely closed connection during stream.");
+      }
+      resolve();
+    })
+  );
+}
+
+function getDecoder(options: {
+  input: Readable;
+  api: APIFormat;
+  logger: typeof logger;
+  contentType?: string;
+}) {
+  const { contentType, input, logger } = options;
+  if (contentType?.includes("application/vnd.amazon.eventstream")) {
+    return getAwsEventStreamDecoder({ input, logger });
+  } else if (contentType?.includes("application/json")) {
+    throw new Error("JSON streaming not supported, request SSE instead");
+  } else {
+    // Ensures split chunks across multi-byte characters are handled correctly.
+    const stringDecoder = new StringDecoder("utf8");
+    return new Transform({
+      readableObjectMode: true,
+      writableObjectMode: false,
+      transform(chunk, _encoding, callback) {
+        const text = stringDecoder.write(chunk);
+        if (text) this.push(text);
+        callback();
+      },
+    });
+  }
+}

src/proxy/middleware/response/index.ts

@@ -1,10 +1,9 @@
 /* This file is fucking horrendous, sorry */
+// TODO: extract all per-service error response handling into its own modules
 import { Request, Response } from "express";
 import * as http from "http";
-import util from "util";
-import zlib from "zlib";
-import { enqueue, trackWaitTime } from "../../queue";
-import { HttpError } from "../../../shared/errors";
+import { config } from "../../../config";
+import { HttpError, RetryableError } from "../../../shared/errors";
 import { keyPool } from "../../../shared/key-management";
 import { getOpenAIModelFamily } from "../../../shared/models";
 import { countTokens } from "../../../shared/tokenization";
@@ -13,45 +12,31 @@ import {
   incrementTokenCount,
 } from "../../../shared/users/user-store";
 import { assertNever } from "../../../shared/utils";
+import { reenqueueRequest, trackWaitTime } from "../../queue";
 import { refundLastAttempt } from "../../rate-limit";
 import {
   getCompletionFromBody,
   isImageGenerationRequest,
   isTextGenerationRequest,
-  writeErrorResponse,
+  sendProxyError,
 } from "../common";
+import { handleBlockingResponse } from "./handle-blocking-response";
 import { handleStreamedResponse } from "./handle-streamed-response";
 import { logPrompt } from "./log-prompt";
+import { logEvent } from "./log-event";
 import { saveImage } from "./save-image";
 
-const DECODER_MAP = {
-  gzip: util.promisify(zlib.gunzip),
-  deflate: util.promisify(zlib.inflate),
-  br: util.promisify(zlib.brotliDecompress),
-};
-
-const isSupportedContentEncoding = (
-  contentEncoding: string
-): contentEncoding is keyof typeof DECODER_MAP => {
-  return contentEncoding in DECODER_MAP;
-};
-
-export class RetryableError extends Error {
-  constructor(message: string) {
-    super(message);
-    this.name = "RetryableError";
-  }
-}
-
 /**
- * Either decodes or streams the entire response body and then passes it as the
- * last argument to the rest of the middleware stack.
+ * Either decodes or streams the entire response body and then resolves with it.
+ * @returns The response body as a string or parsed JSON object depending on the
+ * response's content-type.
  */
 export type RawResponseBodyHandler = (
   proxyRes: http.IncomingMessage,
   req: Request,
   res: Response
 ) => Promise<string | Record<string, any>>;
+
 export type ProxyResHandlerWithBody = (
   proxyRes: http.IncomingMessage,
   req: Request,
@@ -62,7 +47,7 @@ export type ProxyResHandlerWithBody = (
    */
   body: string | Record<string, any>
 ) => Promise<void>;
-export type ProxyResMiddleware = ProxyResHandlerWithBody[];
+export type ProxyResMiddleware = ProxyResHandlerWithBody[] | undefined;
 
 /**
  * Returns a on.proxyRes handler that executes the given middleware stack after
@@ -75,6 +60,10 @@ export type ProxyResMiddleware = ProxyResHandlerWithBody[];
  * middleware from executing as it consumes the stream and forwards events to
  * the client. Once the stream is closed, the finalized body will be attached
  * to res.body and the remaining middleware will execute.
+ *
+ * @param apiMiddleware - Custom middleware to execute after the common response
+ * handlers. These *only* execute for non-streaming responses, so should be used
+ * to transform non-streaming responses into the desired format.
  */
 export const createOnProxyResHandler = (apiMiddleware: ProxyResMiddleware) => {
   return async (
@@ -82,36 +71,47 @@ export const createOnProxyResHandler = (apiMiddleware: ProxyResMiddleware) => {
     req: Request,
     res: Response
   ) => {
+    // Proxied request has by now been sent to the upstream API, so we revert
+    // tracked mutations that were only needed to send the request.
+    // This generally means path adjustment, headers, and body serialization.
+    if (req.changeManager) {
+      req.changeManager.revert();
+    }
+
     const initialHandler = req.isStreaming
       ? handleStreamedResponse
-      : decodeResponseBody;
-
+      : handleBlockingResponse;
     let lastMiddleware = initialHandler.name;
 
+    if (Buffer.isBuffer(req.body)) {
+      req.body = JSON.parse(req.body.toString());
+    }
+
     try {
       const body = await initialHandler(proxyRes, req, res);
-
       const middlewareStack: ProxyResMiddleware = [];
 
       if (req.isStreaming) {
-        // `handleStreamedResponse` writes to the response and ends it, so
-        // we can only execute middleware that doesn't write to the response.
+        // Handlers for streaming requests must never write to the response.
         middlewareStack.push(
-          trackRateLimit,
+          trackKeyRateLimit,
           countResponseTokens,
           incrementUsage,
-          logPrompt
+          logPrompt,
+          logEvent
         );
       } else {
         middlewareStack.push(
-          trackRateLimit,
+          trackKeyRateLimit,
+          injectProxyInfo,
           handleUpstreamErrors,
           countResponseTokens,
           incrementUsage,
           copyHttpHeaders,
           saveImage,
           logPrompt,
-          ...apiMiddleware
+          logEvent,
+          ...(apiMiddleware ?? [])
         );
       }
 
@@ -135,15 +135,15 @@ export const createOnProxyResHandler = (apiMiddleware: ProxyResMiddleware) => {
       }
 
       const { stack, message } = error;
-      const info = { stack, lastMiddleware, key: req.key?.hash };
+      const details = { stack, message, lastMiddleware, key: req.key?.hash };
       const description = `Error while executing proxy response middleware: ${lastMiddleware} (${message})`;
 
       if (res.headersSent) {
-        req.log.error(info, description);
+        req.log.error(details, description);
         if (!res.writableEnded) res.end();
         return;
       } else {
-        req.log.error(info, description);
+        req.log.error(details, description);
         res
           .status(500)
           .json({ error: "Internal server error", proxy_note: description });
@@ -152,72 +152,6 @@ export const createOnProxyResHandler = (apiMiddleware: ProxyResMiddleware) => {
   };
 };
 
-async function reenqueueRequest(req: Request) {
-  req.log.info(
-    { key: req.key?.hash, retryCount: req.retryCount },
-    `Re-enqueueing request due to retryable error`
-  );
-  req.retryCount++;
-  await enqueue(req);
-}
-
-/**
- * Handles the response from the upstream service and decodes the body if
- * necessary.  If the response is JSON, it will be parsed and returned as an
- * object.  Otherwise, it will be returned as a string.
- * @throws {Error} Unsupported content-encoding or invalid application/json body
- */
-export const decodeResponseBody: RawResponseBodyHandler = async (
-  proxyRes,
-  req,
-  res
-) => {
-  if (req.isStreaming) {
-    const err = new Error("decodeResponseBody called for a streaming request.");
-    req.log.error({ stack: err.stack, api: req.inboundApi }, err.message);
-    throw err;
-  }
-
-  return new Promise<string>((resolve, reject) => {
-    let chunks: Buffer[] = [];
-    proxyRes.on("data", (chunk) => chunks.push(chunk));
-    proxyRes.on("end", async () => {
-      let body = Buffer.concat(chunks);
-
-      const contentEncoding = proxyRes.headers["content-encoding"];
-      if (contentEncoding) {
-        if (isSupportedContentEncoding(contentEncoding)) {
-          const decoder = DECODER_MAP[contentEncoding];
-          body = await decoder(body);
-        } else {
-          const errorMessage = `Proxy received response with unsupported content-encoding: ${contentEncoding}`;
-          req.log.warn({ contentEncoding, key: req.key?.hash }, errorMessage);
-          writeErrorResponse(req, res, 500, "Internal Server Error", {
-            error: errorMessage,
-            contentEncoding,
-          });
-          return reject(errorMessage);
-        }
-      }
-
-      try {
-        if (proxyRes.headers["content-type"]?.includes("application/json")) {
-          const json = JSON.parse(body.toString());
-          return resolve(json);
-        }
-        return resolve(body.toString());
-      } catch (error: any) {
-        const errorMessage = `Proxy received response with invalid JSON: ${error.message}`;
-        req.log.warn({ error: error.stack, key: req.key?.hash }, errorMessage);
-        writeErrorResponse(req, res, 500, "Internal Server Error", {
-          error: errorMessage,
-        });
-        return reject(errorMessage);
-      }
-    });
-  });
-};
-
 type ProxiedErrorPayload = {
   error?: Record<string, any>;
   message?: string;
@@ -240,58 +174,64 @@ const handleUpstreamErrors: ProxyResHandlerWithBody = async (
 ) => {
   const statusCode = proxyRes.statusCode || 500;
   const statusMessage = proxyRes.statusMessage || "Internal Server Error";
+  const service = req.key!.service;
+  // Not an error, continue to next response handler
+  if (statusCode < 400) return;
 
-  if (statusCode < 400) {
-    return;
-  }
-
+  // Parse the error response body
   let errorPayload: ProxiedErrorPayload;
-  const tryAgainMessage = keyPool.available(req.body?.model)
-    ? `There may be more keys available for this model; try again in a few seconds.`
-    : "There are no more keys available for this model.";
-
   try {
     assertJsonResponse(body);
     errorPayload = body;
   } catch (parseError) {
-    // Likely Bad Gateway or Gateway Timeout from upstream's reverse proxy
-    const hash = req.key?.hash;
-    req.log.warn({ statusCode, statusMessage, key: hash }, parseError.message);
+    const strBody = String(body).slice(0, 128);
+    req.log.error({ statusCode, strBody }, "Error body is not JSON");
 
-    const errorObject = {
+    const details = {
       error: parseError.message,
       status: statusCode,
       statusMessage,
-      proxy_note: `Proxy got back an error, but it was not in JSON format. This is likely a temporary problem with the upstream service.`,
+      proxy_note: `Proxy got back an error, but it was not in JSON format. This is likely a temporary problem with the upstream service. Response body: ${strBody}`,
     };
 
-    writeErrorResponse(req, res, statusCode, statusMessage, errorObject);
+    sendProxyError(req, res, statusCode, statusMessage, details);
     throw new HttpError(statusCode, parseError.message);
   }
 
+  // Extract the error type from the response body depending on the service
+  if (service === "gcp") {
+    if (Array.isArray(errorPayload)) {
+      errorPayload = errorPayload[0];
+    }
+  }
   const errorType =
     errorPayload.error?.code ||
     errorPayload.error?.type ||
     getAwsErrorType(proxyRes.headers["x-amzn-errortype"]);
 
   req.log.warn(
-    { statusCode, type: errorType, errorPayload, key: req.key?.hash },
-    `Received error response from upstream. (${proxyRes.statusMessage})`
+    { statusCode, statusMessage, errorType, errorPayload, key: req.key?.hash },
+    `API returned an error.`
   );
 
-  const service = req.key!.service;
+  // Try to convert response body to a ProxiedErrorPayload with message/type
   if (service === "aws") {
-    // Try to standardize the error format for AWS
     errorPayload.error = { message: errorPayload.message, type: errorType };
     delete errorPayload.message;
+  } else if (service === "gcp") {
+    if (errorPayload.error?.code) {
+      errorPayload.error = {
+        message: errorPayload.error.message,
+        type: errorPayload.error.status || errorPayload.error.code,
+      };
+    }
   }
 
+  // Figure out what to do with the error
+  // TODO: separate error handling for each service
   if (statusCode === 400) {
-    // Bad request. For OpenAI, this is usually due to prompt length.
-    // For Anthropic, this is usually due to missing preamble.
     switch (service) {
       case "openai":
-      case "google-ai":
       case "mistral-ai":
       case "azure":
         const filteredCodes = ["content_policy_violation", "content_filter"];
@@ -301,14 +241,18 @@ const handleUpstreamErrors: ProxyResHandlerWithBody = async (
         } else if (errorPayload.error?.code === "billing_hard_limit_reached") {
           // For some reason, some models return this 400 error instead of the
           // same 429 billing error that other models return.
-          await handleOpenAIRateLimitError(req, tryAgainMessage, errorPayload);
+          await handleOpenAIRateLimitError(req, errorPayload);
         } else {
-          errorPayload.proxy_note = `The upstream API rejected the request. Your prompt may be too long for ${req.body?.model}.`;
+          errorPayload.proxy_note = `The upstream API rejected the request. Check the error message for details.`;
         }
         break;
       case "anthropic":
       case "aws":
-        await maybeHandleMissingPreambleError(req, errorPayload);
+      case "gcp":
+        await handleAnthropicAwsBadRequestError(req, errorPayload);
+        break;
+      case "google-ai":
+        await handleGoogleAIBadRequestError(req, errorPayload);
         break;
       default:
         assertNever(service);
@@ -316,34 +260,57 @@ const handleUpstreamErrors: ProxyResHandlerWithBody = async (
   } else if (statusCode === 401) {
     // Key is invalid or was revoked
     keyPool.disable(req.key!, "revoked");
-    errorPayload.proxy_note = `API key is invalid or revoked. ${tryAgainMessage}`;
+    errorPayload.proxy_note = `Assigned API key is invalid or revoked, please try again.`;
   } else if (statusCode === 403) {
-    if (service === "anthropic") {
-      keyPool.disable(req.key!, "revoked");
-      errorPayload.proxy_note = `API key is invalid or revoked. ${tryAgainMessage}`;
-      return;
-    }
-    switch (errorType) {
-      case "UnrecognizedClientException":
-        // Key is invalid.
+    switch (service) {
+      case "anthropic":
+        if (
+          errorType === "permission_error" &&
+          errorPayload.error?.message?.toLowerCase().includes("multimodal")
+        ) {
+          keyPool.update(req.key!, { allowsMultimodality: false });
+          await reenqueueRequest(req);
+          throw new RetryableError(
+            "Claude request re-enqueued because key does not support multimodality."
+          );
+        } else {
+          keyPool.disable(req.key!, "revoked");
+          errorPayload.proxy_note = `Assigned API key is invalid or revoked, please try again.`;
+        }
+        return;
+      case "aws":
+        switch (errorType) {
+          case "UnrecognizedClientException":
+            // Key is invalid.
+            keyPool.disable(req.key!, "revoked");
+            errorPayload.proxy_note = `Assigned API key is invalid or revoked, please try again.`;
+            break;
+          case "AccessDeniedException":
+            const isModelAccessError =
+              errorPayload.error?.message?.includes(`specified model ID`);
+            if (!isModelAccessError) {
+              req.log.error(
+                { key: req.key?.hash, model: req.body?.model },
+                "Disabling key due to AccessDeniedException when invoking model. If credentials are valid, check IAM permissions."
+              );
+              keyPool.disable(req.key!, "revoked");
+            }
+            errorPayload.proxy_note = `API key doesn't have access to the requested resource. Model ID: ${req.body?.model}`;
+            break;
+          default:
+            errorPayload.proxy_note = `Received 403 error. Key may be invalid.`;
+        }
+        return;
+      case "mistral-ai":
+      case "gcp":
         keyPool.disable(req.key!, "revoked");
-        errorPayload.proxy_note = `API key is invalid or revoked. ${tryAgainMessage}`;
-        break;
-      case "AccessDeniedException":
-        req.log.error(
-          { key: req.key?.hash, model: req.body?.model },
-          "Disabling key due to AccessDeniedException when invoking model. If credentials are valid, check IAM permissions."
-        );
-        keyPool.disable(req.key!, "revoked");
-        errorPayload.proxy_note = `API key doesn't have access to the requested resource.`;
-        break;
-      default:
-        errorPayload.proxy_note = `Received 403 error. Key may be invalid.`;
+        errorPayload.proxy_note = `Assigned API key is invalid or revoked, please try again.`;
+        return;
     }
   } else if (statusCode === 429) {
     switch (service) {
       case "openai":
-        await handleOpenAIRateLimitError(req, tryAgainMessage, errorPayload);
+        await handleOpenAIRateLimitError(req, errorPayload);
         break;
       case "anthropic":
         await handleAnthropicRateLimitError(req, errorPayload);
@@ -351,6 +318,9 @@ const handleUpstreamErrors: ProxyResHandlerWithBody = async (
       case "aws":
         await handleAwsRateLimitError(req, errorPayload);
         break;
+      case "gcp":
+        await handleGcpRateLimitError(req, errorPayload);
+        break;
       case "azure":
       case "mistral-ai":
         await handleAzureRateLimitError(req, errorPayload);
@@ -365,7 +335,7 @@ const handleUpstreamErrors: ProxyResHandlerWithBody = async (
     // Most likely model not found
     switch (service) {
       case "openai":
-        if (errorPayload.error?.code === "model_not_found") {
+        if (errorType === "model_not_found") {
           const requestedModel = req.body.model;
           const modelFamily = getOpenAIModelFamily(requestedModel);
           errorPayload.proxy_note = `The key assigned to your prompt does not support the requested model (${requestedModel}, family: ${modelFamily}).`;
@@ -376,28 +346,35 @@ const handleUpstreamErrors: ProxyResHandlerWithBody = async (
         }
         break;
       case "anthropic":
-        errorPayload.proxy_note = `The requested Claude model might not exist, or the key might not be provisioned for it.`;
-        break;
       case "google-ai":
-        errorPayload.proxy_note = `The requested Google AI model might not exist, or the key might not be provisioned for it.`;
-        break;
       case "mistral-ai":
-        errorPayload.proxy_note = `The requested Mistral AI model might not exist, or the key might not be provisioned for it.`;
-        break;
       case "aws":
-        errorPayload.proxy_note = `The requested AWS resource might not exist, or the key might not have access to it.`;
-        break;
+      case "gcp":
       case "azure":
-        errorPayload.proxy_note = `The assigned Azure deployment does not support the requested model.`;
+        errorPayload.proxy_note = `The key assigned to your prompt does not support the requested model.`;
         break;
       default:
         assertNever(service);
     }
+  } else if (statusCode === 503) {
+    switch (service) {
+      case "aws":
+        if (
+          errorType === "ServiceUnavailableException" &&
+          errorPayload.error?.message?.match(/too many connections/i)
+        ) {
+          errorPayload.proxy_note = `The requested AWS Bedrock model is overloaded. Try again in a few minutes, or try another model.`;
+        }
+        break;
+      default:
+        errorPayload.proxy_note = `Upstream service unavailable. Try again later.`;
+        break;
+    }
   } else {
     errorPayload.proxy_note = `Unrecognized error from upstream service.`;
   }
 
-  // Some OAI errors contain the organization ID, which we don't want to reveal.
+  // Redact the OpenAI org id from the error message
   if (errorPayload.error?.message) {
     errorPayload.error.message = errorPayload.error.message.replace(
       /org-.{24}/gm,
@@ -405,37 +382,24 @@ const handleUpstreamErrors: ProxyResHandlerWithBody = async (
     );
   }
 
-  writeErrorResponse(req, res, statusCode, statusMessage, errorPayload);
+  // Send the error to the client
+  sendProxyError(req, res, statusCode, statusMessage, errorPayload);
+
+  // Re-throw the error to bubble up to onProxyRes's handler for logging
   throw new HttpError(statusCode, errorPayload.error?.message);
 };
 
-/**
- * This is a workaround for a very strange issue where certain API keys seem to
- * enforce more strict input validation than others -- specifically, they will
- * require a `\n\nHuman:` prefix on the prompt, perhaps to prevent the key from
- * being used as a generic text completion service and to enforce the use of
- * the chat RLHF.  This is not documented anywhere, and it's not clear why some
- * keys enforce this and others don't.
- * This middleware checks for that specific error and marks the key as being
- * one that requires the prefix, and then re-enqueues the request.
- * The exact error is:
- * ```
- * {
- *   "error": {
- *     "type": "invalid_request_error",
- *     "message": "prompt must start with \"\n\nHuman:\" turn"
- *   }
- * }
- * ```
- */
-async function maybeHandleMissingPreambleError(
+async function handleAnthropicAwsBadRequestError(
   req: Request,
   errorPayload: ProxiedErrorPayload
 ) {
-  if (
-    errorPayload.error?.type === "invalid_request_error" &&
-    errorPayload.error?.message === 'prompt must start with "\n\nHuman:" turn'
-  ) {
+  const { error } = errorPayload;
+  const isMissingPreamble = error?.message.startsWith(
+    `prompt must start with "\n\nHuman:" turn`
+  );
+
+  // Some keys mandate a \n\nHuman: preamble, which we can add and retry
+  if (isMissingPreamble) {
     req.log.warn(
       { key: req.key?.hash },
       "Request failed due to missing preamble. Key will be marked as such for subsequent requests."
@@ -443,9 +407,37 @@ async function maybeHandleMissingPreambleError(
     keyPool.update(req.key!, { requiresPreamble: true });
     await reenqueueRequest(req);
     throw new RetryableError("Claude request re-enqueued to add preamble.");
-  } else {
-    errorPayload.proxy_note = `Proxy received unrecognized error from Anthropic. Check the specific error for more information.`;
   }
+
+  // {"type":"error","error":{"type":"invalid_request_error","message":"Usage blocked until 2024-03-01T00:00:00+00:00 due to user specified spend limits."}}
+  // {"type":"error","error":{"type":"invalid_request_error","message":"Your credit balance is too low to access the Claude API. Please go to Plans & Billing to upgrade or purchase credits."}}
+  const isOverQuota =
+    error?.message?.match(/usage blocked until/i) ||
+    error?.message?.match(/credit balance is too low/i);
+  if (isOverQuota) {
+    req.log.warn(
+      { key: req.key?.hash, message: error?.message },
+      "Anthropic key has hit spending limit and will be disabled."
+    );
+    keyPool.disable(req.key!, "quota");
+    errorPayload.proxy_note = `Assigned key has hit its spending limit. ${error?.message}`;
+    return;
+  }
+
+  const isDisabled =
+    error?.message?.match(/organization has been disabled/i) ||
+    error?.message?.match(/^operation not allowed/i);
+  if (isDisabled) {
+    req.log.warn(
+      { key: req.key?.hash, message: error?.message },
+      "Anthropic/AWS key has been disabled."
+    );
+    keyPool.disable(req.key!, "revoked");
+    errorPayload.proxy_note = `Assigned key has been disabled. (${error?.message})`;
+    return;
+  }
+
+  errorPayload.proxy_note = `Unrecognized error from the API. (${error?.message})`;
 }
 
 async function handleAnthropicRateLimitError(
@@ -457,7 +449,7 @@ async function handleAnthropicRateLimitError(
     await reenqueueRequest(req);
     throw new RetryableError("Claude rate-limited request re-enqueued.");
   } else {
-    errorPayload.proxy_note = `Unrecognized rate limit error from Anthropic. Key may be over quota.`;
+    errorPayload.proxy_note = `Unrecognized 429 Too Many Requests error from the API.`;
   }
 }
 
@@ -479,9 +471,21 @@ async function handleAwsRateLimitError(
   }
 }
 
+async function handleGcpRateLimitError(
+  req: Request,
+  errorPayload: ProxiedErrorPayload
+) {
+  if (errorPayload.error?.type === "RESOURCE_EXHAUSTED") {
+    keyPool.markRateLimited(req.key!);
+    await reenqueueRequest(req);
+    throw new RetryableError("GCP rate-limited request re-enqueued.");
+  } else {
+    errorPayload.proxy_note = `Unrecognized 429 Too Many Requests error from GCP.`;
+  }
+}
+
 async function handleOpenAIRateLimitError(
   req: Request,
-  tryAgainMessage: string,
   errorPayload: ProxiedErrorPayload
 ): Promise<Record<string, any>> {
   const type = errorPayload.error?.type;
@@ -490,17 +494,17 @@ async function handleOpenAIRateLimitError(
     case "invalid_request_error": // this is the billing_hard_limit_reached error seen in some cases
       // Billing quota exceeded (key is dead, disable it)
       keyPool.disable(req.key!, "quota");
-      errorPayload.proxy_note = `Assigned key's quota has been exceeded. ${tryAgainMessage}`;
+      errorPayload.proxy_note = `Assigned key's quota has been exceeded. Please try again.`;
       break;
     case "access_terminated":
       // Account banned (key is dead, disable it)
       keyPool.disable(req.key!, "revoked");
-      errorPayload.proxy_note = `Assigned key has been banned by OpenAI for policy violations. ${tryAgainMessage}`;
+      errorPayload.proxy_note = `Assigned key has been banned by OpenAI for policy violations. Please try again.`;
       break;
     case "billing_not_active":
       // Key valid but account billing is delinquent
       keyPool.disable(req.key!, "quota");
-      errorPayload.proxy_note = `Assigned key has been disabled due to delinquent billing. ${tryAgainMessage}`;
+      errorPayload.proxy_note = `Assigned key has been disabled due to delinquent billing. Please try again.`;
       break;
     case "requests":
     case "tokens":
@@ -514,58 +518,8 @@ async function handleOpenAIRateLimitError(
       // Per-minute request or token rate limit is exceeded, which we can retry
       await reenqueueRequest(req);
       throw new RetryableError("Rate-limited request re-enqueued.");
-    // WIP/nonfunctional
-    // case "tokens_usage_based":
-    //   // Weird new rate limit type that seems limited to preview models.
-    //   // Distinct from `tokens` type. Can be per-minute or per-day.
-    //
-    //   // I've seen reports of this error for 500k tokens/day and 10k tokens/min.
-    //   // 10k tokens per minute is problematic, because this is much less than
-    //   // GPT4-Turbo's max context size for a single prompt and is effectively a
-    //   // cap on the max context size for just that key+model, which the app is
-    //   // not able to deal with.
-    //
-    //   // Similarly if there is a 500k tokens per day limit and 450k tokens have
-    //   // been used today, the max context for that key becomes 50k tokens until
-    //   // the next day and becomes progressively smaller as more tokens are used.
-    //
-    //   // To work around these keys we will first retry the request a few times.
-    //   // After that we will reject the request, and if it's a per-day limit we
-    //   // will also disable the key.
-    //
-    //   // "Rate limit reached for gpt-4-1106-preview in organization org-xxxxxxxxxxxxxxxxxxx on tokens_usage_based per day: Limit 500000, Used 460000, Requested 50000"
-    //   // "Rate limit reached for gpt-4-1106-preview in organization org-xxxxxxxxxxxxxxxxxxx on tokens_usage_based per min: Limit 10000, Requested 40000"
-    //
-    //   const regex =
-    //     /Rate limit reached for .+ in organization .+ on \w+ per (day|min): Limit (\d+)(?:, Used (\d+))?, Requested (\d+)/;
-    //   const [, period, limit, used, requested] =
-    //     errorPayload.error?.message?.match(regex) || [];
-    //
-    //   req.log.warn(
-    //     { key: req.key?.hash, period, limit, used, requested },
-    //     "Received `tokens_usage_based` rate limit error from OpenAI."
-    //   );
-    //
-    //   if (!period || !limit || !requested) {
-    //     errorPayload.proxy_note = `Unrecognized rate limit error from OpenAI. (${errorPayload.error?.message})`;
-    //     break;
-    //   }
-    //
-    //   if (req.retryCount < 2) {
-    //     await reenqueueRequest(req);
-    //     throw new RetryableError("Rate-limited request re-enqueued.");
-    //   }
-    //
-    //   if (period === "min") {
-    //     errorPayload.proxy_note = `Assigned key can't be used for prompts longer than ${limit} tokens, and no other keys are available right now. Reduce the length of your prompt or try again in a few minutes.`;
-    //   } else {
-    //     errorPayload.proxy_note = `Assigned key  has reached its per-day request limit for this model. Try another model.`;
-    //   }
-    //
-    //   keyPool.markRateLimited(req.key!);
-    //   break;
     default:
-      errorPayload.proxy_note = `This is likely a temporary error with OpenAI. Try again in a few seconds.`;
+      errorPayload.proxy_note = `This is likely a temporary error with the API. Try again in a few seconds.`;
       break;
   }
   return errorPayload;
@@ -587,17 +541,98 @@ async function handleAzureRateLimitError(
   }
 }
 
+//{"error":{"code":400,"message":"API Key not found. Please pass a valid API key.","status":"INVALID_ARGUMENT","details":[{"@type":"type.googleapis.com/google.rpc.ErrorInfo","reason":"API_KEY_INVALID","domain":"googleapis.com","metadata":{"service":"generativelanguage.googleapis.com"}}]}}
+//{"error":{"code":400,"message":"Gemini API free tier is not available in your country. Please enable billing on your project in Google AI Studio.","status":"FAILED_PRECONDITION"}}
+async function handleGoogleAIBadRequestError(
+  req: Request,
+  errorPayload: ProxiedErrorPayload
+) {
+  const error = errorPayload.error || {};
+  // google changes this shit every few months
+  // i don't want to deal with it
+  const keyDeadMsgs = [
+    /please enable billing/i,
+    /API key not valid/i,
+    /API key expired/i,
+    /pass a valid API/i,
+  ];
+  const text = JSON.stringify(error);
+  if (keyDeadMsgs.some((msg) => text.match(msg))) {
+    req.log.warn(
+      { key: req.key?.hash, error: text },
+      "Google API key appears to be inoperative."
+    );
+    keyPool.disable(req.key!, "revoked");
+    errorPayload.proxy_note = `Assigned API key cannot be used.`;
+  } else {
+    req.log.warn(
+      { key: req.key?.hash, error: text },
+      "Unknown Google API error."
+    );
+    errorPayload.proxy_note = `Unrecognized error from Google AI.`;
+  }
+
+  // const { message, status, details } = error;
+  //
+  // if (status === "INVALID_ARGUMENT") {
+  //   const reason = details?.[0]?.reason;
+  //   if (reason === "API_KEY_INVALID") {
+  //     req.log.warn(
+  //       { key: req.key?.hash, status, reason, msg: error.message },
+  //       "Received `API_KEY_INVALID` error from Google AI. Check the configured API key."
+  //     );
+  //     keyPool.disable(req.key!, "revoked");
+  //     errorPayload.proxy_note = `Assigned API key is invalid.`;
+  //   }
+  // } else if (status === "FAILED_PRECONDITION") {
+  //   if (message.match(/please enable billing/i)) {
+  //     req.log.warn(
+  //       { key: req.key?.hash, status, msg: error.message },
+  //       "Cannot use key due to billing restrictions."
+  //     );
+  //     keyPool.disable(req.key!, "revoked");
+  //     errorPayload.proxy_note = `Assigned API key cannot be used.`;
+  //   }
+  // } else {
+  //   req.log.warn(
+  //     { key: req.key?.hash, status, msg: error.message },
+  //     "Received unexpected 400 error from Google AI."
+  //   );
+  // }
+}
+
 //{"error":{"code":429,"message":"Resource has been exhausted (e.g. check quota).","status":"RESOURCE_EXHAUSTED"}
+//
 async function handleGoogleAIRateLimitError(
   req: Request,
   errorPayload: ProxiedErrorPayload
 ) {
   const status = errorPayload.error?.status;
+  const text = JSON.stringify(errorPayload.error);
+
+  // sometimes they block keys by rate limiting them to 0 requests per minute
+  // for some indefinite period of time
+  const keyDeadMsgs = [
+    /GenerateContentRequestsPerMinutePerProjectPerRegion/i,
+    /"quota_limit_value":"0"/i,
+  ];
+
   switch (status) {
-    case "RESOURCE_EXHAUSTED":
+    case "RESOURCE_EXHAUSTED": {
+      if (keyDeadMsgs.every((msg) => text.match(msg))) {
+        req.log.warn(
+          { key: req.key?.hash, error: text },
+          "Google API key appears to be temporarily inoperative and will be disabled."
+        );
+        keyPool.disable(req.key!, "revoked");
+        errorPayload.proxy_note = `Assigned API key cannot be used.`;
+        return;
+      }
+
       keyPool.markRateLimited(req.key!);
       await reenqueueRequest(req);
       throw new RetryableError("Rate-limited request re-enqueued.");
+    }
     default:
       errorPayload.proxy_note = `Unrecognized rate limit error from Google AI (${status}). Please report this.`;
       break;
@@ -647,15 +682,23 @@ const countResponseTokens: ProxyResHandlerWithBody = async (
     const completion = getCompletionFromBody(req, body);
     const tokens = await countTokens({ req, completion, service });
 
+    if (req.service === "openai" || req.service === "azure") {
+      // O1 consumes (a significant amount of) invisible tokens for the chain-
+      // of-thought reasoning. We have no way to count these other than to check
+      // the response body.
+      tokens.reasoning_tokens =
+        body.usage?.completion_tokens_details?.reasoning_tokens;
+    }
+
     req.log.debug(
-      { service, tokens, prevOutputTokens: req.outputTokens },
+      { service, prevOutputTokens: req.outputTokens, tokens },
       `Counted tokens for completion`
     );
     if (req.tokenizerInfo) {
       req.tokenizerInfo.completion_tokens = tokens;
     }
 
-    req.outputTokens = tokens.token_count;
+    req.outputTokens = tokens.token_count + (tokens.reasoning_tokens ?? 0);
   } catch (error) {
     req.log.warn(
       error,
@@ -666,30 +709,65 @@ const countResponseTokens: ProxyResHandlerWithBody = async (
   }
 };
 
-const trackRateLimit: ProxyResHandlerWithBody = async (proxyRes, req) => {
+const trackKeyRateLimit: ProxyResHandlerWithBody = async (proxyRes, req) => {
   keyPool.updateRateLimits(req.key!, proxyRes.headers);
 };
 
+const omittedHeaders = new Set<string>([
+  // Omit content-encoding because we will always decode the response body
+  "content-encoding",
+  // Omit transfer-encoding because we are using response.json which will
+  // set a content-length header, which is not valid for chunked responses.
+  "transfer-encoding",
+  // Don't set cookies from upstream APIs because proxied requests are stateless
+  "set-cookie",
+  "openai-organization",
+  "x-request-id",
+  "cf-ray",
+]);
 const copyHttpHeaders: ProxyResHandlerWithBody = async (
   proxyRes,
   _req,
   res
 ) => {
   Object.keys(proxyRes.headers).forEach((key) => {
-    // Omit content-encoding because we will always decode the response body
-    if (key === "content-encoding") {
-      return;
-    }
-    // We're usually using res.json() to send the response, which causes express
-    // to set content-length. That's not valid for chunked responses and some
-    // clients will reject it so we need to omit it.
-    if (key === "transfer-encoding") {
-      return;
-    }
+    if (omittedHeaders.has(key)) return;
     res.setHeader(key, proxyRes.headers[key] as string);
   });
 };
 
+/**
+ * Injects metadata into the response, such as the tokenizer used, logging
+ * status, upstream API endpoint used, and whether the input prompt was modified
+ * or transformed.
+ * Only used for non-streaming requests.
+ */
+const injectProxyInfo: ProxyResHandlerWithBody = async (
+  _proxyRes,
+  req,
+  res,
+  body
+) => {
+  const { service, inboundApi, outboundApi, tokenizerInfo } = req;
+  const native = inboundApi === outboundApi;
+  const info: any = {
+    logged: config.promptLogging,
+    tokens: tokenizerInfo,
+    service,
+    in_api: inboundApi,
+    out_api: outboundApi,
+    prompt_transformed: !native,
+  };
+
+  if (req.query?.debug?.length) {
+    info.final_request_body = req.signedRequest?.body || req.body;
+  }
+
+  if (typeof body === "object") {
+    body.proxy = info;
+  }
+};
+
 function getAwsErrorType(header: string | string[] | undefined) {
   const val = String(header).match(/^(\w+):?/)?.[1];
   return val || String(header);
@@ -697,6 +775,6 @@ function getAwsErrorType(header: string | string[] | undefined) {
 
 function assertJsonResponse(body: any): asserts body is Record<string, any> {
   if (typeof body !== "object") {
-    throw new Error("Expected response to be an object");
+    throw new Error(`Expected response to be an object, got ${typeof body}`);
   }
 }

src/proxy/middleware/response/log-event.ts

@@ -0,0 +1,81 @@
+import { createHash } from "crypto";
+import { config } from "../../../config";
+import { eventLogger } from "../../../shared/prompt-logging";
+import { getModelFromBody, isTextGenerationRequest } from "../common";
+import { ProxyResHandlerWithBody } from ".";
+import {
+  OpenAIChatMessage,
+  AnthropicChatMessage,
+} from "../../../shared/api-schemas";
+
+/** If event logging is enabled, logs a chat completion event. */
+export const logEvent: ProxyResHandlerWithBody = async (
+  _proxyRes,
+  req,
+  _res,
+  responseBody
+) => {
+  if (!config.eventLogging) {
+    return;
+  }
+  if (typeof responseBody !== "object") {
+    throw new Error("Expected body to be an object");
+  }
+  if (!["openai", "anthropic-chat"].includes(req.outboundApi)) {
+    // only chat apis are supported
+    return;
+  }
+  if (!req.user) {
+    return;
+  }
+
+  const loggable = isTextGenerationRequest(req);
+  if (!loggable) return;
+
+  const messages = req.body.messages as
+    | OpenAIChatMessage[]
+    | AnthropicChatMessage[];
+
+  let hashes = [];
+  hashes.push(hashMessages(messages));
+  for (
+    let i = 1;
+    i <= Math.min(config.eventLoggingTrim!, messages.length);
+    i++
+  ) {
+    hashes.push(hashMessages(messages.slice(0, -i)));
+  }
+
+  const model = getModelFromBody(req, responseBody);
+  const userToken = req.user!.token;
+  const family = req.modelFamily!;
+  eventLogger.logEvent({
+    ip: req.ip,
+    type: "chat_completion",
+    model,
+    family,
+    hashes,
+    userToken,
+    inputTokens: req.promptTokens ?? 0,
+    outputTokens: req.outputTokens ?? 0,
+  });
+};
+
+const hashMessages = (
+  messages: OpenAIChatMessage[] | AnthropicChatMessage[]
+): string => {
+  let hasher = createHash("sha256");
+  let messageTexts = [];
+  for (const msg of messages) {
+    if (!["system", "user", "assistant"].includes(msg.role)) continue;
+    if (typeof msg.content === "string") {
+      messageTexts.push(msg.content);
+    } else if (Array.isArray(msg.content)) {
+      if (msg.content[0].type === "text") {
+        messageTexts.push(msg.content[0].text);
+      }
+    }
+  }
+  hasher.update(messageTexts.join("<|im_sep|>"));
+  return hasher.digest("hex");
+};

src/proxy/middleware/response/log-prompt.ts

@@ -10,9 +10,12 @@ import {
 import { ProxyResHandlerWithBody } from ".";
 import { assertNever } from "../../../shared/utils";
 import {
+  AnthropicChatMessage,
+  flattenAnthropicMessages,
+  GoogleAIChatMessage,
   MistralAIChatMessage,
   OpenAIChatMessage,
-} from "../request/preprocessors/transform-outbound-payload";
+} from "../../../shared/api-schemas";
 
 /** If prompt logging is enabled, enqueues the prompt for logging. */
 export const logPrompt: ProxyResHandlerWithBody = async (
@@ -57,7 +60,13 @@ type OaiImageResult = {
 const getPromptForRequest = (
   req: Request,
   responseBody: Record<string, any>
-): string | OpenAIChatMessage[] | MistralAIChatMessage[] | OaiImageResult => {
+):
+  | string
+  | OpenAIChatMessage[]
+  | { contents: GoogleAIChatMessage[] }
+  | { system: string; messages: AnthropicChatMessage[] }
+  | MistralAIChatMessage[]
+  | OaiImageResult => {
   // Since the prompt logger only runs after the request has been proxied, we
   // can assume the body has already been transformed to the target API's
   // format.
@@ -65,7 +74,17 @@ const getPromptForRequest = (
     case "openai":
     case "mistral-ai":
       return req.body.messages;
+    case "anthropic-chat":
+      let system = req.body.system;
+      if (Array.isArray(system)) {
+        system = system
+          .map((m: { type: string; text: string }) => m.text)
+          .join("\n");
+      }
+      return { system, messages: req.body.messages };
     case "openai-text":
+    case "anthropic-text":
+    case "mistral-text":
       return req.body.prompt;
     case "openai-image":
       return {
@@ -75,21 +94,37 @@ const getPromptForRequest = (
         quality: req.body.quality,
         revisedPrompt: responseBody.data[0].revised_prompt,
       };
-    case "anthropic":
-      return req.body.prompt;
     case "google-ai":
-      return req.body.prompt.text;
+      return { contents: req.body.contents };
     default:
       assertNever(req.outboundApi);
   }
 };
 
 const flattenMessages = (
-  val: string | OpenAIChatMessage[] | MistralAIChatMessage[] | OaiImageResult
+  val:
+    | string
+    | OaiImageResult
+    | OpenAIChatMessage[]
+    | { contents: GoogleAIChatMessage[] }
+    | { system: string; messages: AnthropicChatMessage[] }
+    | MistralAIChatMessage[]
 ): string => {
   if (typeof val === "string") {
     return val.trim();
   }
+  if (isAnthropicChatPrompt(val)) {
+    const { system, messages } = val;
+    return `System: ${system}\n\n${flattenAnthropicMessages(messages)}`;
+  }
+  if (isGoogleAIChatPrompt(val)) {
+    return val.contents
+      .map(({ parts, role }) => {
+        const text = parts.map((p) => p.text).join("\n");
+        return `${role}: ${text}`;
+      })
+      .join("\n");
+  }
   if (Array.isArray(val)) {
     return val
       .map(({ content, role }) => {
@@ -98,6 +133,8 @@ const flattenMessages = (
               .map((c) => {
                 if ("text" in c) return c.text;
                 if ("image_url" in c) return "(( Attached Image ))";
+                if ("source" in c) return "(( Attached Image ))";
+                return "(( Unsupported Content ))";
               })
               .join("\n")
           : content;
@@ -107,3 +144,20 @@ const flattenMessages = (
   }
   return val.prompt.trim();
 };
+
+function isGoogleAIChatPrompt(
+  val: unknown
+): val is { contents: GoogleAIChatMessage[] } {
+  return typeof val === "object" && val !== null && "contents" in val;
+}
+
+function isAnthropicChatPrompt(
+  val: unknown
+): val is { system: string; messages: AnthropicChatMessage[] } {
+  return (
+    typeof val === "object" &&
+    val !== null &&
+    "system" in val &&
+    "messages" in val
+  );
+}

src/proxy/middleware/response/save-image.ts

@@ -1,11 +1,14 @@
 import { ProxyResHandlerWithBody } from "./index";
-import { mirrorGeneratedImage, OpenAIImageGenerationResult } from "../../../shared/file-storage/mirror-generated-image";
+import {
+  mirrorGeneratedImage,
+  OpenAIImageGenerationResult,
+} from "../../../shared/file-storage/mirror-generated-image";
 
 export const saveImage: ProxyResHandlerWithBody = async (
   _proxyRes,
   req,
   _res,
-  body,
+  body
 ) => {
   if (req.outboundApi !== "openai-image") {
     return;
@@ -16,12 +19,15 @@ export const saveImage: ProxyResHandlerWithBody = async (
   }
 
   if (body.data) {
-    const baseUrl = req.protocol + "://" + req.get("host");
     const prompt = body.data[0].revised_prompt ?? req.body.prompt;
-    await mirrorGeneratedImage(
-      baseUrl,
+    const res = await mirrorGeneratedImage(
+      req,
       prompt,
       body as OpenAIImageGenerationResult
     );
+    req.log.info(
+      { urls: res.data.map((item) => item.url) },
+      "Saved generated image to user_content"
+    );
   }
 };

src/proxy/middleware/response/streaming/aggregators/anthropic-chat.ts

@@ -0,0 +1,49 @@
+import { OpenAIChatCompletionStreamEvent } from "../index";
+
+export type AnthropicChatCompletionResponse = {
+  id: string;
+  type: "message";
+  role: "assistant";
+  content: { type: "text"; text: string }[];
+  model: string;
+  stop_reason: string | null;
+  stop_sequence: string | null;
+  usage: { input_tokens: number; output_tokens: number };
+};
+
+/**
+ * Given a list of OpenAI chat completion events, compiles them into a single
+ * finalized Anthropic chat completion response so that non-streaming middleware
+ * can operate on it as if it were a blocking response.
+ */
+export function mergeEventsForAnthropicChat(
+  events: OpenAIChatCompletionStreamEvent[]
+): AnthropicChatCompletionResponse {
+  let merged: AnthropicChatCompletionResponse = {
+    id: "",
+    type: "message",
+    role: "assistant",
+    content: [],
+    model: "",
+    stop_reason: null,
+    stop_sequence: null,
+    usage: { input_tokens: 0, output_tokens: 0 },
+  };
+  merged = events.reduce((acc, event, i) => {
+    // The first event will only contain role assignment and response metadata
+    if (i === 0) {
+      acc.id = event.id;
+      acc.model = event.model;
+      acc.content = [{ type: "text", text: "" }];
+      return acc;
+    }
+
+    acc.stop_reason = event.choices[0].finish_reason ?? "";
+    if (event.choices[0].delta.content) {
+      acc.content[0].text += event.choices[0].delta.content;
+    }
+
+    return acc;
+  }, merged);
+  return merged;
+}

src/proxy/middleware/response/streaming/aggregators/anthropic-text.ts

@@ -1,6 +1,6 @@
 import { OpenAIChatCompletionStreamEvent } from "../index";
 
-export type AnthropicCompletionResponse = {
+export type AnthropicTextCompletionResponse = {
   completion: string;
   stop_reason: string;
   truncated: boolean;
@@ -15,10 +15,10 @@ export type AnthropicCompletionResponse = {
  * finalized Anthropic completion response so that non-streaming middleware
  * can operate on it as if it were a blocking response.
  */
-export function mergeEventsForAnthropic(
+export function mergeEventsForAnthropicText(
   events: OpenAIChatCompletionStreamEvent[]
-): AnthropicCompletionResponse {
-  let merged: AnthropicCompletionResponse = {
+): AnthropicTextCompletionResponse {
+  let merged: AnthropicTextCompletionResponse = {
     log_id: "",
     exception: null,
     model: "",

src/proxy/middleware/response/streaming/aggregators/mistral-chat.ts

@@ -0,0 +1,39 @@
+import { OpenAIChatCompletionStreamEvent } from "../index";
+
+export type MistralChatCompletionResponse = {
+  choices: {
+    index: number;
+    message: { role: string; content: string };
+    finish_reason: string | null;
+  }[];
+};
+
+/**
+ * Given a list of OpenAI chat completion events, compiles them into a single
+ * finalized Mistral chat completion response so that non-streaming middleware
+ * can operate on it as if it were a blocking response.
+ */
+export function mergeEventsForMistralChat(
+  events: OpenAIChatCompletionStreamEvent[]
+): MistralChatCompletionResponse {
+  let merged: MistralChatCompletionResponse = {
+    choices: [
+      { index: 0, message: { role: "", content: "" }, finish_reason: "" },
+    ],
+  };
+  merged = events.reduce((acc, event, i) => {
+    // The first event will only contain role assignment and response metadata
+    if (i === 0) {
+      acc.choices[0].message.role = event.choices[0].delta.role ?? "assistant";
+      return acc;
+    }
+
+    acc.choices[0].finish_reason = event.choices[0].finish_reason ?? "";
+    if (event.choices[0].delta.content) {
+      acc.choices[0].message.content += event.choices[0].delta.content;
+    }
+
+    return acc;
+  }, merged);
+  return merged;
+}

src/proxy/middleware/response/streaming/aggregators/mistral-text.ts

@@ -0,0 +1,33 @@
+import { OpenAIChatCompletionStreamEvent } from "../index";
+
+export type MistralTextCompletionResponse = {
+  outputs: {
+    text: string;
+    stop_reason: string | null;
+  }[];
+};
+
+/**
+ * Given a list of OpenAI chat completion events, compiles them into a single
+ * finalized Mistral text completion response so that non-streaming middleware
+ * can operate on it as if it were a blocking response.
+ */
+export function mergeEventsForMistralText(
+  events: OpenAIChatCompletionStreamEvent[]
+): MistralTextCompletionResponse {
+  let merged: MistralTextCompletionResponse = {
+    outputs: [{ text: "", stop_reason: "" }],
+  };
+  merged = events.reduce((acc, event, i) => {
+    // The first event will only contain role assignment and response metadata
+    if (i === 0) {
+      return acc;
+    }
+
+    acc.outputs[0].text += event.choices[0].delta.content ?? "";
+    acc.outputs[0].stop_reason = event.choices[0].finish_reason ?? "";
+
+    return acc;
+  }, merged);
+  return merged;
+}

src/proxy/middleware/response/streaming/aws-event-stream-decoder.ts

@@ -0,0 +1,93 @@
+import pino from "pino";
+import { Duplex, Readable } from "stream";
+import { EventStreamMarshaller } from "@smithy/eventstream-serde-node";
+import { fromUtf8, toUtf8 } from "@smithy/util-utf8";
+import { Message } from "@smithy/eventstream-codec";
+
+/**
+ * Decodes a Readable stream, such as a proxied HTTP response, into a stream of
+ * Message objects using the AWS SDK's EventStreamMarshaller. Error events in
+ * the amazon eventstream protocol are decoded as Message objects and will not
+ * emit an error event on the decoder stream.
+ */
+export function getAwsEventStreamDecoder(params: {
+  input: Readable;
+  logger: pino.Logger;
+}): Duplex {
+  const { input, logger } = params;
+  const config = { utf8Encoder: toUtf8, utf8Decoder: fromUtf8 };
+  const eventStream = new EventStreamMarshaller(config).deserialize(
+    input,
+    async (input: Record<string, Message>) => {
+      const eventType = Object.keys(input)[0];
+      let result;
+      if (eventType === "chunk") {
+        result = input[eventType];
+      } else {
+        // AWS unmarshaller treats non-chunk events (errors and exceptions) oddly.
+        result = { [eventType]: input[eventType] } as any;
+      }
+      return result;
+    }
+  );
+  return new AWSEventStreamDecoder(eventStream, { logger });
+}
+
+class AWSEventStreamDecoder extends Duplex {
+  private readonly asyncIterable: AsyncIterable<Message>;
+  private iterator: AsyncIterator<Message>;
+  private reading: boolean;
+  private logger: pino.Logger;
+
+  constructor(
+    asyncIterable: AsyncIterable<Message>,
+    options: { logger: pino.Logger }
+  ) {
+    super({ ...options, objectMode: true });
+    this.asyncIterable = asyncIterable;
+    this.iterator = this.asyncIterable[Symbol.asyncIterator]();
+    this.reading = false;
+    this.logger = options.logger.child({ module: "aws-eventstream-decoder" });
+  }
+
+  async _read(_size: number) {
+    if (this.reading) return;
+    this.reading = true;
+
+    try {
+      while (true) {
+        const { value, done } = await this.iterator.next();
+        if (done) {
+          this.push(null);
+          break;
+        }
+        if (!this.push(value)) break;
+      }
+    } catch (err) {
+      // AWS SDK's EventStreamMarshaller emits errors in the stream itself as
+      // whatever our deserializer returns, which will not be Error objects
+      // because we want to pass the Message to the next stream for processing.
+      // Any actual Error thrown here is some failure during deserialization.
+      const isAwsError = !(err instanceof Error);
+
+      if (isAwsError) {
+        this.logger.warn({ err: err.headers }, "Received AWS error event");
+        this.push(err);
+        this.push(null);
+      } else {
+        this.logger.error(err, "Error during AWS stream deserialization");
+        this.destroy(err);
+      }
+    } finally {
+      this.reading = false;
+    }
+  }
+
+  _write(_chunk: any, _encoding: string, callback: () => void) {
+    callback();
+  }
+
+  _final(callback: () => void) {
+    callback();
+  }
+}

src/proxy/middleware/response/streaming/event-aggregator.ts

@@ -1,10 +1,19 @@
+import express from "express";
 import { APIFormat } from "../../../../shared/key-management";
 import { assertNever } from "../../../../shared/utils";
 import {
-  mergeEventsForAnthropic,
+  anthropicV2ToOpenAI,
+  mergeEventsForAnthropicChat,
+  mergeEventsForAnthropicText,
   mergeEventsForOpenAIChat,
   mergeEventsForOpenAIText,
+  mergeEventsForMistralChat,
+  mergeEventsForMistralText,
+  AnthropicV2StreamEvent,
   OpenAIChatCompletionStreamEvent,
+  mistralAIToOpenAI,
+  MistralAIStreamEvent,
+  MistralChatCompletionEvent,
 } from "./index";
 
 /**
@@ -12,32 +21,111 @@ import {
  * compiles them into a single finalized response for downstream middleware.
  */
 export class EventAggregator {
-  private readonly format: APIFormat;
+  private readonly model: string;
+  private readonly requestFormat: APIFormat;
+  private readonly responseFormat: APIFormat;
   private readonly events: OpenAIChatCompletionStreamEvent[];
 
-  constructor({ format }: { format: APIFormat }) {
+  constructor({ body, inboundApi, outboundApi }: express.Request) {
     this.events = [];
-    this.format = format;
+    this.requestFormat = inboundApi;
+    this.responseFormat = outboundApi;
+    this.model = body.model;
   }
 
-  addEvent(event: OpenAIChatCompletionStreamEvent) {
-    this.events.push(event);
+  addEvent(
+    event:
+      | OpenAIChatCompletionStreamEvent
+      | AnthropicV2StreamEvent
+      | MistralAIStreamEvent
+  ) {
+    if (eventIsOpenAIEvent(event)) {
+      this.events.push(event);
+    } else {
+      // horrible special case. previously all transformers' target format was
+      // openai, so the event aggregator could conveniently assume all incoming
+      // events were in openai format.
+      // now we have added some transformers that convert between non-openai
+      // formats, so aggregator needs to know how to collapse for more than
+      // just openai.
+      // because writing aggregation logic for every possible output format is
+      // annoying, we will just transform any non-openai output events to openai
+      // format (even if the client did not request openai at all) so that we
+      // still only need to write aggregators for openai SSEs.
+      let openAIEvent: OpenAIChatCompletionStreamEvent | undefined;
+      switch (this.requestFormat) {
+        case "anthropic-text":
+          assertIsAnthropicV2Event(event);
+          openAIEvent = anthropicV2ToOpenAI({
+            data: `event: completion\ndata: ${JSON.stringify(event)}\n\n`,
+            lastPosition: -1,
+            index: 0,
+            fallbackId: event.log_id || "fallback-" + Date.now(),
+            fallbackModel: event.model || this.model || "fallback-claude-3",
+          })?.event;
+          break;
+        case "mistral-ai":
+          assertIsMistralChatEvent(event);
+          openAIEvent = mistralAIToOpenAI({
+            data: `data: ${JSON.stringify(event)}\n\n`,
+            lastPosition: -1,
+            index: 0,
+            fallbackId: "fallback-" + Date.now(),
+            fallbackModel: this.model || "fallback-mistral",
+          })?.event;
+          break;
+      }
+      if (openAIEvent) {
+        this.events.push(openAIEvent);
+      }
+    }
   }
 
   getFinalResponse() {
-    switch (this.format) {
+    switch (this.responseFormat) {
       case "openai":
-      case "google-ai":
-      case "mistral-ai":
+      case "google-ai": // TODO: this is probably wrong now that we support native Google Makersuite prompts
         return mergeEventsForOpenAIChat(this.events);
       case "openai-text":
         return mergeEventsForOpenAIText(this.events);
-      case "anthropic":
-        return mergeEventsForAnthropic(this.events);
+      case "anthropic-text":
+        return mergeEventsForAnthropicText(this.events);
+      case "anthropic-chat":
+        return mergeEventsForAnthropicChat(this.events);
+      case "mistral-ai":
+        return mergeEventsForMistralChat(this.events);
+      case "mistral-text":
+        return mergeEventsForMistralText(this.events);
       case "openai-image":
-        throw new Error(`SSE aggregation not supported for ${this.format}`);
+        throw new Error(
+          `SSE aggregation not supported for ${this.responseFormat}`
+        );
       default:
-        assertNever(this.format);
+        assertNever(this.responseFormat);
     }
   }
+
+  hasEvents() {
+    return this.events.length > 0;
+  }
+}
+
+function eventIsOpenAIEvent(
+  event: any
+): event is OpenAIChatCompletionStreamEvent {
+  return event?.object === "chat.completion.chunk";
+}
+
+function assertIsAnthropicV2Event(event: any): asserts event is AnthropicV2StreamEvent {
+  if (!event?.completion) {
+    throw new Error(`Bad event for Anthropic V2 SSE aggregation`);
+  }
+}
+
+function assertIsMistralChatEvent(
+  event: any
+): asserts event is MistralChatCompletionEvent {
+  if (!event?.choices) {
+    throw new Error(`Bad event for Mistral SSE aggregation`);
+  }
 }

src/proxy/middleware/response/streaming/index.ts

@@ -1,9 +1,36 @@
-export type SSEResponseTransformArgs = {
+export type SSEResponseTransformArgs<S = Record<string, any>> = {
   data: string;
   lastPosition: number;
   index: number;
   fallbackId: string;
   fallbackModel: string;
+  state?: S;
+};
+
+export type MistralChatCompletionEvent = {
+  choices: {
+    index: number;
+    message: { role: string; content: string };
+    stop_reason: string | null;
+  }[];
+};
+export type MistralTextCompletionEvent = {
+  outputs: { text: string; stop_reason: string | null }[];
+};
+export type MistralAIStreamEvent = {
+  "amazon-bedrock-invocationMetrics"?: {
+    inputTokenCount: number;
+    outputTokenCount: number;
+    invocationLatency: number;
+    firstByteLatency: number;
+  };
+} & (MistralChatCompletionEvent | MistralTextCompletionEvent);
+
+export type AnthropicV2StreamEvent = {
+  log_id?: string;
+  model?: string;
+  completion: string;
+  stop_reason: string | null;
 };
 
 export type OpenAIChatCompletionStreamEvent = {
@@ -16,17 +43,29 @@ export type OpenAIChatCompletionStreamEvent = {
     delta: { role?: string; content?: string };
     finish_reason: string | null;
   }[];
-}
+};
 
-export type StreamingCompletionTransformer = (
-  params: SSEResponseTransformArgs
-) => { position: number; event?: OpenAIChatCompletionStreamEvent };
+export type StreamingCompletionTransformer<
+  T = OpenAIChatCompletionStreamEvent,
+  S = any,
+> = (params: SSEResponseTransformArgs<S>) => {
+  position: number;
+  event?: T;
+  state?: S;
+};
 
 export { openAITextToOpenAIChat } from "./transformers/openai-text-to-openai";
 export { anthropicV1ToOpenAI } from "./transformers/anthropic-v1-to-openai";
 export { anthropicV2ToOpenAI } from "./transformers/anthropic-v2-to-openai";
+export { anthropicChatToAnthropicV2 } from "./transformers/anthropic-chat-to-anthropic-v2";
+export { anthropicChatToOpenAI } from "./transformers/anthropic-chat-to-openai";
 export { googleAIToOpenAI } from "./transformers/google-ai-to-openai";
+export { mistralAIToOpenAI } from "./transformers/mistral-ai-to-openai";
+export { mistralTextToMistralChat } from "./transformers/mistral-text-to-mistral-chat";
 export { passthroughToOpenAI } from "./transformers/passthrough-to-openai";
 export { mergeEventsForOpenAIChat } from "./aggregators/openai-chat";
 export { mergeEventsForOpenAIText } from "./aggregators/openai-text";
-export { mergeEventsForAnthropic } from "./aggregators/anthropic";
+export { mergeEventsForAnthropicText } from "./aggregators/anthropic-text";
+export { mergeEventsForAnthropicChat } from "./aggregators/anthropic-chat";
+export { mergeEventsForMistralChat } from "./aggregators/mistral-chat";
+export { mergeEventsForMistralText } from "./aggregators/mistral-text";

src/proxy/middleware/response/streaming/parse-sse.ts

@@ -3,27 +3,27 @@ export type ServerSentEvent = { id?: string; type?: string; data: string };
 /** Given a string of SSE data, parse it into a `ServerSentEvent` object. */
 export function parseEvent(event: string) {
   const buffer: ServerSentEvent = { data: "" };
-  return event.split(/\r?\n/).reduce(parseLine, buffer)
+  return event.split(/\r?\n/).reduce(parseLine, buffer);
 }
 
 function parseLine(event: ServerSentEvent, line: string) {
   const separator = line.indexOf(":");
-  const field = separator === -1 ? line : line.slice(0,separator);
+  const field = separator === -1 ? line : line.slice(0, separator);
   const value = separator === -1 ? "" : line.slice(separator + 1);
 
   switch (field) {
-    case 'id':
-      event.id = value.trim()
-      break
-    case 'event':
-      event.type = value.trim()
-      break
-    case 'data':
-      event.data += value.trimStart()
-      break
+    case "id":
+      event.id = value.trim();
+      break;
+    case "event":
+      event.type = value.trim();
+      break;
+    case "data":
+      event.data += value.trimStart();
+      break;
     default:
-      break
+      break;
   }
 
-  return event
-}
+  return event;
+}

src/proxy/middleware/response/streaming/sse-message-transformer.ts

@@ -3,23 +3,28 @@ import { logger } from "../../../../logger";
 import { APIFormat } from "../../../../shared/key-management";
 import { assertNever } from "../../../../shared/utils";
 import {
+  anthropicChatToOpenAI,
+  anthropicChatToAnthropicV2,
   anthropicV1ToOpenAI,
+  AnthropicV2StreamEvent,
   anthropicV2ToOpenAI,
+  googleAIToOpenAI,
   OpenAIChatCompletionStreamEvent,
   openAITextToOpenAIChat,
-  googleAIToOpenAI,
+  mistralAIToOpenAI,
+  mistralTextToMistralChat,
   passthroughToOpenAI,
   StreamingCompletionTransformer,
+  MistralChatCompletionEvent,
 } from "./index";
 
-const genlog = logger.child({ module: "sse-transformer" });
-
 type SSEMessageTransformerOptions = TransformOptions & {
   requestedModel: string;
   requestId: string;
   inputFormat: APIFormat;
   inputApiVersion?: string;
-  logger?: typeof logger;
+  outputFormat?: APIFormat;
+  logger: typeof logger;
 };
 
 /**
@@ -28,21 +33,28 @@ type SSEMessageTransformerOptions = TransformOptions & {
  */
 export class SSEMessageTransformer extends Transform {
   private lastPosition: number;
+  private transformState: any;
   private msgCount: number;
   private readonly inputFormat: APIFormat;
-  private readonly transformFn: StreamingCompletionTransformer;
+  private readonly transformFn: StreamingCompletionTransformer<
+    // TODO: Refactor transformers to not assume only OpenAI events as output
+    | OpenAIChatCompletionStreamEvent
+    | AnthropicV2StreamEvent
+    | MistralChatCompletionEvent
+  >;
   private readonly log;
   private readonly fallbackId: string;
   private readonly fallbackModel: string;
 
   constructor(options: SSEMessageTransformerOptions) {
     super({ ...options, readableObjectMode: true });
-    this.log = options.logger?.child({ module: "sse-transformer" }) ?? genlog;
+    this.log = options.logger?.child({ module: "sse-transformer" });
     this.lastPosition = 0;
     this.msgCount = 0;
     this.transformFn = getTransformer(
       options.inputFormat,
-      options.inputApiVersion
+      options.inputApiVersion,
+      options.outputFormat
     );
     this.inputFormat = options.inputFormat;
     this.fallbackId = options.requestId;
@@ -60,15 +72,20 @@ export class SSEMessageTransformer extends Transform {
   _transform(chunk: Buffer, _encoding: BufferEncoding, callback: Function) {
     try {
       const originalMessage = chunk.toString();
-      const { event: transformedMessage, position: newPosition } =
-        this.transformFn({
-          data: originalMessage,
-          lastPosition: this.lastPosition,
-          index: this.msgCount++,
-          fallbackId: this.fallbackId,
-          fallbackModel: this.fallbackModel,
-        });
+      const {
+        event: transformedMessage,
+        position: newPosition,
+        state,
+      } = this.transformFn({
+        data: originalMessage,
+        lastPosition: this.lastPosition,
+        index: this.msgCount++,
+        fallbackId: this.fallbackId,
+        fallbackModel: this.fallbackModel,
+        state: this.transformState,
+      });
       this.lastPosition = newPosition;
+      this.transformState = state;
 
       // Special case for Azure OpenAI, which is 99% the same as OpenAI but
       // sometimes emits an extra event at the beginning of the stream with the
@@ -86,7 +103,7 @@ export class SSEMessageTransformer extends Transform {
       // Some events may not be transformed, e.g. ping events
       if (!transformedMessage) return callback();
 
-      if (this.msgCount === 1) {
+      if (this.msgCount === 1 && eventIsOpenAIEvent(transformedMessage)) {
         // TODO: does this need to be skipped for passthroughToOpenAI?
         this.push(createInitialMessage(transformedMessage));
       }
@@ -100,22 +117,45 @@ export class SSEMessageTransformer extends Transform {
   }
 }
 
+function eventIsOpenAIEvent(
+  event: any
+): event is OpenAIChatCompletionStreamEvent {
+  return event?.object === "chat.completion.chunk";
+}
+
 function getTransformer(
   responseApi: APIFormat,
-  version?: string
-): StreamingCompletionTransformer {
+  version?: string,
+  // In most cases, we are transforming back to OpenAI. Some responses can be
+  // translated between two non-OpenAI formats, eg Anthropic Chat -> Anthropic
+  // Text, or Mistral Text -> Mistral Chat.
+  requestApi: APIFormat = "openai"
+): StreamingCompletionTransformer<
+  | OpenAIChatCompletionStreamEvent
+  | AnthropicV2StreamEvent
+  | MistralChatCompletionEvent
+> {
   switch (responseApi) {
     case "openai":
-    case "mistral-ai":
       return passthroughToOpenAI;
     case "openai-text":
       return openAITextToOpenAIChat;
-    case "anthropic":
+    case "anthropic-text":
       return version === "2023-01-01"
         ? anthropicV1ToOpenAI
         : anthropicV2ToOpenAI;
+    case "anthropic-chat":
+      return requestApi === "anthropic-text"
+        ? anthropicChatToAnthropicV2 // User's legacy text prompt was converted to chat, and response must be converted back to text
+        : anthropicChatToOpenAI;
     case "google-ai":
       return googleAIToOpenAI;
+    case "mistral-ai":
+      return mistralAIToOpenAI;
+    case "mistral-text":
+      return requestApi === "mistral-ai"
+        ? mistralTextToMistralChat // User's chat request was converted to text, and response must be converted back to chat
+        : mistralAIToOpenAI;
     case "openai-image":
       throw new Error(`SSE transformation not supported for ${responseApi}`);
     default:

src/proxy/middleware/response/streaming/sse-stream-adapter.ts

@@ -1,140 +1,121 @@
+import pino from "pino";
 import { Transform, TransformOptions } from "stream";
-
-import { StringDecoder } from "string_decoder";
-// @ts-ignore
-import { Parser } from "lifion-aws-event-stream";
-import { logger } from "../../../../logger";
-import { RetryableError } from "../index";
+import { Message } from "@smithy/eventstream-codec";
 import { APIFormat } from "../../../../shared/key-management";
-import StreamArray from "stream-json/streamers/StreamArray";
-import { makeCompletionSSE } from "../../../../shared/streaming";
-
-const log = logger.child({ module: "sse-stream-adapter" });
+import { BadRequestError, RetryableError } from "../../../../shared/errors";
 
 type SSEStreamAdapterOptions = TransformOptions & {
   contentType?: string;
   api: APIFormat;
-};
-type AwsEventStreamMessage = {
-  headers: {
-    ":message-type": "event" | "exception";
-    ":exception-type"?: string;
-  };
-  payload: { message?: string /** base64 encoded */; bytes?: string };
+  logger: pino.Logger;
 };
 
 /**
- * Receives either text chunks or AWS binary event stream chunks and emits
- * full SSE events.
+ * Receives a stream of events in a variety of formats and transforms them into
+ * Server-Sent Events.
+ *
+ * This is an object-mode stream, so it expects to receive objects and will emit
+ * strings.
  */
 export class SSEStreamAdapter extends Transform {
   private readonly isAwsStream;
-  private readonly isGoogleStream;
-  private awsParser = new Parser();
-  private jsonParser = StreamArray.withParser();
+  private api: APIFormat;
   private partialMessage = "";
-  private decoder = new StringDecoder("utf8");
+  private textDecoder = new TextDecoder("utf8");
+  private log: pino.Logger;
 
-  constructor(options?: SSEStreamAdapterOptions) {
-    super(options);
+  constructor(options: SSEStreamAdapterOptions) {
+    super({ ...options, objectMode: true });
     this.isAwsStream =
       options?.contentType === "application/vnd.amazon.eventstream";
-    this.isGoogleStream = options?.api === "google-ai";
-
-    this.awsParser.on("data", (data: AwsEventStreamMessage) => {
-      const message = this.processAwsEvent(data);
-      if (message) {
-        this.push(Buffer.from(message + "\n\n"), "utf8");
-      }
-    });
-
-    this.jsonParser.on("data", (data: { value: any }) => {
-      const message = this.processGoogleValue(data.value);
-      if (message) {
-        this.push(Buffer.from(message + "\n\n"), "utf8");
-      }
-    });
+    this.api = options.api;
+    this.log = options.logger.child({ module: "sse-stream-adapter" });
   }
 
-  protected processAwsEvent(event: AwsEventStreamMessage): string | null {
-    const { payload, headers } = event;
-    if (headers[":message-type"] === "exception" || !payload.bytes) {
-      const eventStr = JSON.stringify(event);
-      // Under high load, AWS can rugpull us by returning a 200 and starting the
-      // stream but then immediately sending a rate limit error as the first
-      // event. My guess is some race condition in their rate limiting check
-      // that occurs if two requests arrive at the same time when only one
-      // concurrency slot is available.
-      if (headers[":exception-type"] === "throttlingException") {
-        log.warn(
-          { event: eventStr },
-          "AWS request throttled after streaming has already started; retrying"
-        );
-        throw new RetryableError("AWS request throttled mid-stream");
-      } else {
-        log.error({ event: eventStr }, "Received bad AWS stream event");
-        return makeCompletionSSE({
-          format: "anthropic",
-          title: "Proxy stream error",
-          message:
-            "The proxy received malformed or unexpected data from AWS while streaming.",
-          obj: event,
-          reqId: "proxy-sse-adapter-message",
-          model: "",
-        });
-      }
-    } else {
-      const { bytes } = payload;
-      // technically this is a transformation but we don't really distinguish
-      // between aws claude and anthropic claude at the APIFormat level, so
-      // these will short circuit the message transformer
-      return [
-        "event: completion",
-        `data: ${Buffer.from(bytes, "base64").toString("utf8")}`,
-      ].join("\n");
+  protected processAwsMessage(message: Message): string | null {
+    // Per amazon, headers and body are always present. headers is an object,
+    // body is a Uint8Array, potentially zero-length.
+    const { headers, body } = message;
+    const eventType = headers[":event-type"]?.value;
+    const messageType = headers[":message-type"]?.value;
+    const contentType = headers[":content-type"]?.value;
+    const exceptionType = headers[":exception-type"]?.value;
+    const errorCode = headers[":error-code"]?.value;
+    const bodyStr = this.textDecoder.decode(body);
+
+    switch (messageType) {
+      case "event":
+        if (contentType === "application/json" && eventType === "chunk") {
+          const { bytes } = JSON.parse(bodyStr);
+          const event = Buffer.from(bytes, "base64").toString("utf8");
+          const eventObj = JSON.parse(event);
+
+          if ("completion" in eventObj) {
+            return ["event: completion", `data: ${event}`].join(`\n`);
+          } else if (eventObj.type) {
+            return [`event: ${eventObj.type}`, `data: ${event}`].join(`\n`);
+          } else {
+            return `data: ${event}`;
+          }
+        }
+      // noinspection FallThroughInSwitchStatementJS -- non-JSON data is unexpected
+      case "exception":
+      case "error":
+        const type = String(
+          exceptionType || errorCode || "UnknownError"
+        ).toLowerCase();
+        switch (type) {
+          case "throttlingexception":
+            this.log.warn(
+              "AWS request throttled after streaming has already started; retrying"
+            );
+            throw new RetryableError("AWS request throttled mid-stream");
+          case "validationexception":
+            try {
+              const { message } = JSON.parse(bodyStr);
+              this.log.error({ message }, "Received AWS validation error");
+              this.emit(
+                "error",
+                new BadRequestError(`AWS validation error: ${message}`)
+              );
+              return null;
+            } catch (error) {
+              this.log.error(
+                { body: bodyStr, error },
+                "Could not parse AWS validation error"
+              );
+            }
+          // noinspection FallThroughInSwitchStatementJS -- who knows what this is
+          default:
+            let text;
+            try {
+              text = JSON.parse(bodyStr).message;
+            } catch (error) {
+              text = bodyStr;
+            }
+            const error: any = new Error(
+              `Got mysterious error chunk: [${type}] ${text}`
+            );
+            error.lastEvent = text;
+            this.emit("error", error);
+            return null;
+        }
+      default:
+        // Amazon says this can't ever happen...
+        this.log.error({ message }, "Received very bad AWS stream event");
+        return null;
     }
   }
 
-  // Google doesn't use event streams and just sends elements in an array over
-  // a long-lived HTTP connection. Needs stream-json to parse the array.
-  protected processGoogleValue(value: any): string | null {
-    try {
-      const candidates = value.candidates ?? [{}];
-      const hasParts = candidates[0].content?.parts?.length > 0;
-      if (hasParts) {
-        return `data: ${JSON.stringify(value)}`;
-      } else {
-        log.error({ event: value }, "Received bad Google AI event");
-        return `data: ${makeCompletionSSE({
-          format: "google-ai",
-          title: "Proxy stream error",
-          message:
-            "The proxy received malformed or unexpected data from Google AI while streaming.",
-          obj: value,
-          reqId: "proxy-sse-adapter-message",
-          model: "",
-        })}`;
-      }
-    } catch (error) {
-      error.lastEvent = value;
-      this.emit("error", error);
-      return null;
-    }
-  }
-
-  _transform(chunk: Buffer, _encoding: BufferEncoding, callback: Function) {
+  _transform(data: any, _enc: string, callback: (err?: Error | null) => void) {
     try {
       if (this.isAwsStream) {
-        this.awsParser.write(chunk);
-      } else if (this.isGoogleStream) {
-        this.jsonParser.write(chunk);
+        // `data` is a Message object
+        const message = this.processAwsMessage(data);
+        if (message) this.push(message + "\n\n");
       } else {
-        // We may receive multiple (or partial) SSE messages in a single chunk,
-        // so we need to buffer and emit separate stream events for full
-        // messages so we can parse/transform them properly.
-        const str = this.decoder.write(chunk);
-
-        const fullMessages = (this.partialMessage + str).split(
+        // `data` is a string, but possibly only a partial message
+        const fullMessages = (this.partialMessage + data).split(
           /\r\r|\n\n|\r\n\r\n/
         );
         this.partialMessage = fullMessages.pop() || "";
@@ -148,9 +129,12 @@ export class SSEStreamAdapter extends Transform {
       }
       callback();
     } catch (error) {
-      error.lastEvent = chunk?.toString();
-      this.emit("error", error);
+      error.lastEvent = data?.toString() ?? "[SSEStreamAdapter] no data";
       callback(error);
     }
   }
+
+  _flush(callback: (err?: Error | null) => void) {
+    callback();
+  }
 }

src/proxy/middleware/response/streaming/transformers/anthropic-chat-to-anthropic-v2.ts

@@ -0,0 +1,129 @@
+import {
+  AnthropicV2StreamEvent,
+  StreamingCompletionTransformer,
+} from "../index";
+import { parseEvent, ServerSentEvent } from "../parse-sse";
+import { logger } from "../../../../../logger";
+
+const log = logger.child({
+  module: "sse-transformer",
+  transformer: "anthropic-chat-to-anthropic-v2",
+});
+
+export type AnthropicChatEventType =
+  | "message_start"
+  | "content_block_start"
+  | "content_block_delta"
+  | "content_block_stop"
+  | "message_delta"
+  | "message_stop";
+
+type AnthropicChatStartEvent = {
+  type: "message_start";
+  message: {
+    id: string;
+    type: "message";
+    role: "assistant";
+    content: [];
+    model: string;
+    stop_reason: null;
+    stop_sequence: null;
+    usage: { input_tokens: number; output_tokens: number };
+  };
+};
+
+type AnthropicChatContentBlockStartEvent = {
+  type: "content_block_start";
+  index: number;
+  content_block: { type: "text"; text: string };
+};
+
+export type AnthropicChatContentBlockDeltaEvent = {
+  type: "content_block_delta";
+  index: number;
+  delta: { type: "text_delta"; text: string };
+};
+
+type AnthropicChatContentBlockStopEvent = {
+  type: "content_block_stop";
+  index: number;
+};
+
+type AnthropicChatMessageDeltaEvent = {
+  type: "message_delta";
+  delta: {
+    stop_reason: string;
+    stop_sequence: null;
+    usage: { output_tokens: number };
+  };
+};
+
+type AnthropicChatMessageStopEvent = {
+  type: "message_stop";
+};
+
+type AnthropicChatTransformerState = { content: string };
+
+/**
+ * Transforms an incoming Anthropic Chat SSE to an equivalent Anthropic V2
+ * Text SSE.
+ * For now we assume there is only one content block and message delta. In the
+ * future Anthropic may add multi-turn responses or multiple content blocks
+ * (probably for multimodal responses, image generation, etc) but as far as I
+ * can tell this is not yet implemented.
+ */
+export const anthropicChatToAnthropicV2: StreamingCompletionTransformer<
+  AnthropicV2StreamEvent,
+  AnthropicChatTransformerState
+> = (params) => {
+  const { data } = params;
+
+  const rawEvent = parseEvent(data);
+  if (!rawEvent.data || !rawEvent.type) {
+    return { position: -1 };
+  }
+
+  const deltaEvent = asAnthropicChatDelta(rawEvent);
+  if (!deltaEvent) {
+    return { position: -1 };
+  }
+
+  const newEvent = {
+    log_id: params.fallbackId,
+    model: params.fallbackModel,
+    completion: deltaEvent.delta.text,
+    stop_reason: null,
+  };
+
+  return { position: -1, event: newEvent };
+};
+
+export function asAnthropicChatDelta(
+  event: ServerSentEvent
+): AnthropicChatContentBlockDeltaEvent | null {
+  if (
+    !event.type ||
+    !["content_block_start", "content_block_delta"].includes(event.type)
+  ) {
+    return null;
+  }
+
+  try {
+    const parsed = JSON.parse(event.data);
+    if (parsed.type === "content_block_delta") {
+      return parsed;
+    } else if (parsed.type === "content_block_start") {
+      return {
+        type: "content_block_delta",
+        index: parsed.index,
+        delta: { type: "text_delta", text: parsed.content_block?.text ?? "" },
+      };
+    } else {
+      // noinspection ExceptionCaughtLocallyJS
+      throw new Error("Invalid event type");
+    }
+  } catch (error) {
+    log.warn({ error: error.stack, event }, "Received invalid event");
+  }
+  return null;
+}

src/proxy/middleware/response/streaming/transformers/anthropic-chat-to-openai.ts

@@ -0,0 +1,45 @@
+import { StreamingCompletionTransformer } from "../index";
+import { parseEvent } from "../parse-sse";
+import { logger } from "../../../../../logger";
+import { asAnthropicChatDelta } from "./anthropic-chat-to-anthropic-v2";
+
+const log = logger.child({
+  module: "sse-transformer",
+  transformer: "anthropic-chat-to-openai",
+});
+
+/**
+ * Transforms an incoming Anthropic Chat SSE to an equivalent OpenAI
+ * chat.completion.chunks SSE.
+ */
+export const anthropicChatToOpenAI: StreamingCompletionTransformer = (
+  params
+) => {
+  const { data } = params;
+
+  const rawEvent = parseEvent(data);
+  if (!rawEvent.data || !rawEvent.type) {
+    return { position: -1 };
+  }
+
+  const deltaEvent = asAnthropicChatDelta(rawEvent);
+  if (!deltaEvent) {
+    return { position: -1 };
+  }
+
+  const newEvent = {
+    id: params.fallbackId,
+    object: "chat.completion.chunk" as const,
+    created: Date.now(),
+    model: params.fallbackModel,
+    choices: [
+      {
+        index: 0,
+        delta: { content: deltaEvent.delta.text },
+        finish_reason: null,
+      },
+    ],
+  };
+
+  return { position: -1, event: newEvent };
+};