- AI
- Dev tools
Mistral AI opens a Responses API for building agents
Mistral AI announced a new Responses API in public preview on October 28, built specifically for developers creating agents on its platform.
·1 min read·AB
Mistral AI @MistralAI
Today, we’re introducing the Responses API in public preview, made for building agents on Mistral.
Each response returns the model’s answer, its reasoning and its tool calls as separate items, so your app can handle every step more easily than with Chat Completions.
It works… pic.twitter.com/5zgjZgqugd
Mistral AI announced a new Responses API in public preview on October 28, built specifically for developers creating agents on its platform. The key change from Mistral's existing Chat Completions API is that each response now splits the model's output into separate items: the final answer, the model's reasoning, and any tool calls it made along the way.
For developers, that separation matters because it means an application no longer has to parse one blended block of text to figure out what the model decided versus what it actually did. A tool call arrives as its own distinct item rather than being mixed in with conversational text, which should make it simpler to track, log, or act on each step of an agent's work individually.
Mistral says the Responses API works with every chat model it hosts, including its Large 4 model, so existing users can adopt it without switching models.
Why it matters
Separating an agent's answer, reasoning and tool calls into distinct items makes it easier for developers to build reliable, inspectable multi-step agents.
Source: Mistral AI on X