Mistral opens Responses API in public preview, borrowing OpenAI’s format for agent builders

The stateless endpoint supports multimodal inputs, JSON outputs, streaming and function calling on Mistral's hosted chat models Mistral AI wants switching AI providers to feel less like moving house and more like changing a lightbulb. The company has released its Responses API in public preview. The new interface lets developers build agents and applications on top of Mistral’s hosted chat models. The API is built to mirror OpenAI’s Responses format, so developers already working in that format won’t need to learn a new one from scratch. What the Responses API actually does The service launched in October 2026. It lives at the /v1/responses endpoint on Mistral’s Studio/API platform. Developers can work with it through official SDKs for Python and TypeScript. The API is stateless. Mistral’s servers don’t hold on to the conversation. Your application has to store the chat history and send it along with every request. On the input side, the API is multimodal. It accepts text, files and images, with images supplied either as URLs or as base64 data. Outputs can be structured as JSON. Instead of a free-form paragraph that a program has to parse, the model returns data in a predictable, m...