Feature: Add support for Mistral API

.example.env

@@ -2,4 +2,5 @@ OPENAI_API_KEY=<Your OpenAI API key>
 COHERE_API_KEY=<Your Cohere API key>
 ANTHROPIC_API_KEY=<Your Anthropic API key>
 AI21_API_KEY=<Your Anthropic API key>
-REPLICATE_API_KEY=<Your Replicate API key>
+REPLICATE_API_KEY=<Your Replicate API key>
+MISTRAL_API_KEY=<Your Mistral API Key>

src/completion.ts

@@ -15,6 +15,7 @@ import { OpenAIHandler } from './handlers/openai';
 import { AI21Handler } from './handlers/ai21';
 import { ReplicateHandler } from './handlers/replicate';
 import { DeepInfraHandler } from './handlers/deepinfra';
+import { MistralHandler } from './handlers/mistral';
 
 export const MODEL_HANDLER_MAPPINGS: Record<string, Handler> = {
   'claude-': AnthropicHandler,
@@ -24,6 +25,7 @@ export const MODEL_HANDLER_MAPPINGS: Record<string, Handler> = {
   'j2-': AI21Handler,
   'replicate/': ReplicateHandler,
   'deepinfra/': DeepInfraHandler,
+  'mistral/': MistralHandler,
 };
 
 export async function completion(

src/handlers/mistral.ts

@@ -0,0 +1,86 @@
+import { ChatCompletion } from 'openai/resources/chat';
+
+import {
+  HandlerParams,
+  HandlerParamsNotStreaming,
+  HandlerParamsStreaming,
+  Message,
+  ResultNotStreaming,
+  ResultStreaming,
+  StreamingChunk,
+} from '../types';
+
+async function* iterateResponse(
+  response: Response,
+): AsyncIterable<StreamingChunk> {
+  const reader = response.body?.getReader();
+  let done = false;
+
+  while (!done) {
+    const next = await reader?.read();
+    if (next?.value) {
+      done = next.done;
+      const decoded = new TextDecoder().decode(next.value);
+      if (decoded.startsWith('data: [DONE]')) {
+        done = true;
+      } else {
+        const [, value] = decoded.split('data: ');
+        yield JSON.parse(value);
+      }
+    } else {
+      done = true;
+    }
+  }
+}
+
+async function getMistralResponse(
+  model: string,
+  messages: Message[],
+  baseUrl: string,
+  stream: boolean,
+): Promise<Response> {
+  return fetch(`${baseUrl}/v1/chat/completions`, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+      Authorization: `Bearer ${process.env.MISTRAL_API_KEY}`,
+    },
+    body: JSON.stringify({
+      messages,
+      model,
+      stream,
+    }),
+  });
+}
+
+export async function MistralHandler(
+  params: HandlerParamsNotStreaming,
+): Promise<ResultNotStreaming>;
+
+export async function MistralHandler(
+  params: HandlerParamsStreaming,
+): Promise<ResultStreaming>;
+
+export async function MistralHandler(
+  params: HandlerParams,
+): Promise<ResultNotStreaming | ResultStreaming>;
+
+export async function MistralHandler(
+  params: HandlerParams,
+): Promise<ResultNotStreaming | ResultStreaming> {
+  const baseUrl = params.baseUrl ?? 'https://api.mistral.ai';
+  const model = params.model.split('mistral/')[1];
+
+  const res = await getMistralResponse(
+    model,
+    params.messages,
+    baseUrl,
+    params.stream ?? false,
+  );
+
+  if (params.stream) {
+    return iterateResponse(res);
+  }
+
+  return res.json() as Promise<ChatCompletion>;
+}

tests/e2e.test.ts

@@ -17,6 +17,7 @@ describe('e2e', () => {
       ${'j2-light'}
       ${'replicate/meta/llama-2-70b-chat:02e509c789964a7ea8736978a43525956ef40397be9033abf9fd2badfe68c9e3'}
       ${'deepinfra/mistralai/Mistral-7B-Instruct-v0.1'}
+      ${'mistral/mistral-tiny'}
     `(
       'gets response from supported model $model',
       async ({ model }) => {
@@ -39,6 +40,7 @@ describe('e2e', () => {
       ${'j2-light'}
       ${'replicate/meta/llama-2-7b-chat:ac944f2e49c55c7e965fc3d93ad9a7d9d947866d6793fb849dd6b4747d0c061c'}
       ${'deepinfra/mistralai/Mistral-7B-Instruct-v0.1'}
+      ${'mistral/mistral-tiny'}
     `(
       'gets streaming response from supported model $model',
       async ({ model }) => {

tests/handlers/getHandler.test.ts

@@ -4,6 +4,7 @@ import { AnthropicHandler } from '../../src/handlers/anthropic';
 import { CohereHandler } from '../../src/handlers/cohere';
 import { DeepInfraHandler } from '../../src/handlers/deepinfra';
 import { getHandler } from '../../src/handlers/getHandler';
+import { MistralHandler } from '../../src/handlers/mistral';
 import { OllamaHandler } from '../../src/handlers/ollama';
 import { OpenAIHandler } from '../../src/handlers/openai';
 import { ReplicateHandler } from '../../src/handlers/replicate';
@@ -23,6 +24,7 @@ describe('getHandler', () => {
     { model: 'j2-ultra-instruct', expectedHandler: AI21Handler },
     { model: 'replicate/test/test', expectedHandler: ReplicateHandler },
     { model: 'deepinfra/test/test', expectedHandler: DeepInfraHandler },
+    { model: 'mistral/mistral-tiny', expectedHandler: MistralHandler },
     { model: 'unknown', expectedHandler: null },
   ])(
     'should return the correct handler for a given model name',