Files
OAI-Proxy/src/proxy/openai-image.ts
T

130 lines
3.6 KiB
TypeScript

import { Request, RequestHandler, Router } from "express";
import { OpenAIImageGenerationResult } from "../shared/file-storage/mirror-generated-image";
import { generateModelList } from "./openai";
import { ipLimiter } from "./rate-limit";
import {
addKey,
createPreprocessorMiddleware,
finalizeBody,
} from "./middleware/request";
import { ProxyResHandlerWithBody } from "./middleware/response";
import { ProxyReqManager } from "./middleware/request/proxy-req-manager";
import { createQueuedProxyMiddleware } from "./middleware/request/proxy-middleware-factory";
const KNOWN_MODELS = ["dall-e-2", "dall-e-3"];
let modelListCache: any = null;
let modelListValid = 0;
const handleModelRequest: RequestHandler = (_req, res) => {
if (new Date().getTime() - modelListValid < 1000 * 60) {
return res.status(200).json(modelListCache);
}
const result = generateModelList("openai").filter((m: { id: string }) =>
KNOWN_MODELS.includes(m.id)
);
modelListCache = { object: "list", data: result };
modelListValid = new Date().getTime();
res.status(200).json(modelListCache);
};
const openaiImagesResponseHandler: 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 === "openai") {
req.log.info("Transforming OpenAI image response to OpenAI chat format");
newBody = transformResponseForChat(
body as OpenAIImageGenerationResult,
req
);
}
res.status(200).json({ ...newBody, proxy: body.proxy });
};
/**
* Transforms a DALL-E image generation response into a chat response, simply
* embedding the image URL into the chat message as a Markdown image.
*/
function transformResponseForChat(
imageBody: OpenAIImageGenerationResult,
req: Request
): Record<string, any> {
const prompt = imageBody.data[0].revised_prompt ?? req.body.prompt;
const content = imageBody.data
.map((item) => {
const { url, b64_json } = item;
if (b64_json) {
return `![${prompt}](data:image/png;base64,${b64_json})`;
} else {
return `![${prompt}](${url})`;
}
})
.join("\n\n");
return {
id: "dalle-" + req.id,
object: "chat.completion",
created: Date.now(),
model: req.body.model,
usage: {
prompt_tokens: 0,
completion_tokens: req.outputTokens,
total_tokens: req.outputTokens,
},
choices: [
{
message: { role: "assistant", content },
finish_reason: "stop",
index: 0,
},
],
};
}
function replacePath(manager: ProxyReqManager) {
const req = manager.request;
const pathname = req.url.split("?")[0];
req.log.debug({ pathname }, "OpenAI image path filter");
if (req.path.startsWith("/v1/chat/completions")) {
manager.setPath("/v1/images/generations");
}
}
const openaiImagesProxy = createQueuedProxyMiddleware({
target: "https://api.openai.com",
mutations: [replacePath, addKey, finalizeBody],
blockingResponseHandler: openaiImagesResponseHandler,
});
const openaiImagesRouter = Router();
openaiImagesRouter.get("/v1/models", handleModelRequest);
openaiImagesRouter.post(
"/v1/images/generations",
ipLimiter,
createPreprocessorMiddleware({
inApi: "openai-image",
outApi: "openai-image",
service: "openai",
}),
openaiImagesProxy
);
openaiImagesRouter.post(
"/v1/chat/completions",
ipLimiter,
createPreprocessorMiddleware({
inApi: "openai",
outApi: "openai-image",
service: "openai",
}),
openaiImagesProxy
);
export const openaiImage = openaiImagesRouter;