Mistral as a drop-in for OpenAI

Mistral's /v1/chat/completions endpoint accepts the same JSON schema as OpenAI's, so most SDKs and frameworks work by swapping the base URL and API key. Here's the mapping.

Quick answer: Mistral provides an OpenAI-compatible API at the base URL https://api.mistral.ai/v1. You can use standard OpenAI SDKs by setting baseURL to Mistral's endpoint and providing your Mistral API key as the bearer token, utilizing standard chat completions and embedding endpoints seamlessly.

1. Base URL & auth

OPENAI_API_BASE=https://api.mistral.ai/v1
OPENAI_API_KEY=<your-mistral-key>   # get one at console.mistral.ai
Authorization: Bearer <your-mistral-key>

2. OpenAI Python SDK

from openai import OpenAI

client = OpenAI(
    base_url="https://api.mistral.ai/v1",
    api_key="<your-mistral-key>",
)

resp = client.chat.completions.create(
    model="mistral-large-latest",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(resp.choices[0].message.content)

3. curl

curl https://api.mistral.ai/v1/chat/completions \
  -H "Authorization: Bearer $MISTRAL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mistral-large-latest",
    "messages": [{"role": "user", "content": "Say hi"}],
    "stream": false
  }'

4. Model-name mapping

5. Supported endpoints

• /v1/chat/completions — full parity, including streaming and tool calls.
• /v1/embeddings — model mistral-embed.
• /v1/models — list available models on your key.
• Not mirrored: Assistants, vision inputs on OpenAI schema, audio, image gen. Use Mistral's native SDK for agents and file inputs.

6. Common gotchas

• Response format: use { "type": "json_object" } — same as OpenAI.
• System prompts: supported, but Mistral models weight them slightly differently — retest your prompts.
• Tool choice: tool_choice: "auto" | "any" | "none" — "any" replaces OpenAI's "required".
• Rate limits: per-key and per-model, in requests/min and tokens/min — see console.mistral.ai → Usage.

FAQ