diff --git a/src/shared/key-management/index.ts b/src/shared/key-management/index.ts
index 95c6530..5d9f4f2 100644
--- a/src/shared/key-management/index.ts
+++ b/src/shared/key-management/index.ts
@@ -1,12 +1,25 @@
-import { OPENAI_SUPPORTED_MODELS, OpenAIModel } from "./openai/provider";
+import type { ModelFamily } from "../models";
+import { KeyPool } from "./key-pool";
+import {
+  OPENAI_SUPPORTED_MODELS,
+  OpenAIKey,
+  OpenAIModel,
+} from "./openai/provider";
 import {
   ANTHROPIC_SUPPORTED_MODELS,
+  AnthropicKey,
   AnthropicModel,
 } from "./anthropic/provider";
-import { GOOGLE_PALM_SUPPORTED_MODELS, GooglePalmModel } from "./palm/provider";
-import { AWS_BEDROCK_SUPPORTED_MODELS, AwsBedrockModel } from "./aws/provider";
-import { KeyPool } from "./key-pool";
-import type { ModelFamily } from "../models";
+import {
+  GOOGLE_PALM_SUPPORTED_MODELS,
+  GooglePalmKey,
+  GooglePalmModel,
+} from "./palm/provider";
+import {
+  AWS_BEDROCK_SUPPORTED_MODELS,
+  AwsBedrockKey,
+  AwsBedrockModel,
+} from "./aws/provider";
 
 /** The request and response format used by a model's API. */
 export type APIFormat = "openai" | "anthropic" | "google-palm" | "openai-text";
@@ -18,6 +31,11 @@ export type Model =
   | GooglePalmModel
   | AwsBedrockModel;
 
+type AllKeys = OpenAIKey | AnthropicKey | GooglePalmKey | AwsBedrockKey;
+export type ServiceToKey = {
+  [K in AllKeys["service"]]: Extract<AllKeys, { service: K }>;
+};
+
 export interface Key {
   /** The API key itself. Never log this, use `hash` instead. */
   readonly key: string;
@@ -83,4 +101,4 @@ export { GooglePalmKey } from "./palm/provider";
 export { AwsBedrockKey } from "./aws/provider";
 export { assertSerializedKey } from "./serializers";
 export { SerializedKey } from "./serializers";
-export { KeySerializer } from "./serializers";
\ No newline at end of file
+export { KeySerializer } from "./serializers";
diff --git a/src/shared/key-management/key-pool.ts b/src/shared/key-management/key-pool.ts
index bcb9076..111d803 100644
--- a/src/shared/key-management/key-pool.ts
+++ b/src/shared/key-management/key-pool.ts
@@ -4,7 +4,7 @@ import os from "os";
 import schedule from "node-schedule";
 import { config } from "../../config";
 import { logger } from "../../logger";
-import { Key, Model, KeyProvider, LLMService } from "./index";
+import { Key, KeyProvider, LLMService, Model, ServiceToKey } from "./index";
 import { getSerializer } from "./serializers";
 import { FirebaseKeyStore, KeyStore, MemoryKeyStore } from "./stores";
 import { AnthropicKeyProvider } from "./anthropic/provider";
@@ -153,7 +153,9 @@ export class KeyPool {
   }
 }
 
-function createKeyStore(service: LLMService): KeyStore<Key> {
+function createKeyStore<S extends LLMService>(
+  service: S
+): KeyStore<ServiceToKey[S]> {
   const serializer = getSerializer(service);
 
   switch (config.persistenceProvider) {
@@ -165,3 +167,4 @@ function createKeyStore(service: LLMService): KeyStore<Key> {
       throw new Error(`Unknown store type: ${config.persistenceProvider}`);
   }
 }
+
diff --git a/src/shared/key-management/serializers.ts b/src/shared/key-management/serializers.ts
index 076c6fb..8132862 100644
--- a/src/shared/key-management/serializers.ts
+++ b/src/shared/key-management/serializers.ts
@@ -1,5 +1,5 @@
-import { Key, LLMService } from ".";
 import { assertNever } from "../utils";
+import { Key, LLMService, ServiceToKey } from "./index";
 import { OpenAIKeySerializer } from "./openai/serializer";
 import { AnthropicKeySerializer } from "./anthropic/serializer";
 import { GooglePalmKeySerializer } from "./palm/serializer";
@@ -41,6 +41,9 @@ export function assertSerializedKey(k: any): asserts k is SerializedKey {
   }
 }
 
+export function getSerializer<S extends LLMService>(
+  service: S
+): KeySerializer<ServiceToKey[S]>;
 export function getSerializer(service: LLMService): KeySerializer<Key> {
   switch (service) {
     case "openai":