Mistral Vibe: Utility Models for Session Titles and Smart Approve

Mistral VibeOct 5, 2026View original changelog

Mistral Vibe 2.26.0 introduced [utility_models] config so users can pick the model behind session titles and smart approve. Session titles are also generated by default in the CLI again and run on the session's own model, with a fast small model used where a deployment serves one.

Key Takeaways

A new [utility_models] config section selects the model for session titles and smart approve.
Setting a feature to active pins it to the model the session runs.
Deployments with a small model now get fast titles and a fast smart-approve classifier automatically.
Without a small model, helpers run on the session model, which costs more per call.
Session titles are on by default in the CLI again, with session_logging.generate_titles = false to opt out.
Titles now describe the whole task, stay stable after resume and use tool results for context.

Choosing the model behind the helpers

Mistral Vibe uses small side calls for housekeeping: naming sessions and classifying commands for smart approve. Version 2.26.0 lets users control which model handles them through a new [utility_models] section in the config. Setting a feature to active pins it to the model the session already runs.

Smarter defaults for custom deployments

Mistral Vibe now checks once whether a deployment serves a small, fast model, instead of guessing from the endpoint address. Custom and self-hosted Mistral deployments that do serve a small model now get fast session titles and a fast smart-approve classifier rather than falling back to the coding model.

Where no small model is available, both features run on the session's own model. That costs more per call, so the release notes recommend naming a cheaper model under [utility_models].

Session titles return by default

Session titles are now generated by default for the CLI, reversing the earlier off-by-default setting. Users can opt out with session_logging.generate_titles = false. Titles also improved: they describe the whole task, stop changing after a single confirmation pass, survive a resume unchanged, and draw on tool results such as fetched pull requests and changed files so terse prompts still get a useful name.

Smart approve fixes

A related fix stops smart approve from sending every classification to a model name a deployment may not serve, which previously made it ask for approval on every call.