What is MistralAI-User, and how do I block it?

MistralAI-User is Mistral AI's user-triggered fetcher. A user-triggered fetcher runs when a person asks an AI product to open a page, not on a schedule. From the operator's wording: user actions in Vibe.

This is the user agent string Mistral AI documents for MistralAI-User, as of October 29, 2026. Version numbers and details can change, so match on the token in robots.txt, not on the whole string.

Add this group to the robots.txt file at the root of your site. It asks MistralAI-User to stay out of every page.

To allow it explicitly, for example while a broader rule blocks other bots:

Each Mistral AI user agent has its own token, so you can set them one by one. This file blocks MistralAI-Training and allows MistralAI-User, MistralAI-Index. Every line comes from the rows in this dataset. Whether allowing a bot keeps you in a product is Mistral AI's call, so check each crawler's page.

Mistral AI does not say what blocking MistralAI-User changes. That is not stated.

Each other Mistral AI user agent has its own robots.txt token, so a rule for MistralAI-User does not cover them. See the related crawlers below.

Not stated. Mistral: MistralAI-User 'governs which sites these user requests can be made to'; an explicit statement about honoring robots.txt was not captured.

Robots.txt is a request, not a lock (RFC 9309).

Mistral AI publishes a list at https://mistral.ai/mistralai-user-ips.json. We did not download or parse it. A request that claims to be MistralAI-User but comes from outside that list is not MistralAI-User.