Mistral Vibe Turns Off Automatic Session Titles by Default
Mistral VibeMistral Vibe reversed the default on a feature it introduced only weeks earlier: background LLM-generated session titles are now off by default, and developers who want them back need to explicitly set session_logging.generate_titles = true. The auto-generated session title feature, which uses the underlying model to name sessions and terminal windows, previously ran automatically for every session; now it requires opt-in.
Key Takeaways
- Automatic session titles are now off by default, reversing the behavior Mistral Vibe introduced only weeks before, in late August 2026.
- Developers must explicitly set
session_logging.generate_titles = trueto restore the feature. - The reversal likely reflects the latency and model-usage cost of running a background LLM call for every session just to generate a title.
- The underlying feature, generating descriptive session and terminal window titles, is unchanged, only its default is.
- The change is a good example of
Changedbullets mattering as much as new features: an existing, user-visible behavior is different after upgrading. - Developers who liked the August rollout should check their config after updating to v2.25.1, since the feature won't reappear automatically.
A Fast Reversal on a Recent Feature
In late August 2026, Mistral Vibe introduced automatically generated session titles, using the underlying LLM to produce descriptive names for sessions and matching terminal window titles instead of generic defaults. Less than two weeks later, in v2.25.1, Mistral Vibe changed the default for that same feature: background LLM session titles are now off by default, and a developer has to explicitly set session_logging.generate_titles = true to bring the behavior back.
What Likely Prompted the Change
The changelog doesn't spell out the reasoning, but making a background LLM call for every session, purely to generate a title, carries a real and recurring cost in latency and model usage across every session a developer starts, whether or not they care about the title. Turning it off by default while keeping it available as an opt-in config value suggests Mistral Vibe wants developers who value the feature to keep it, without paying that cost for everyone automatically.
What Developers Should Check
Anyone who got used to seeing descriptive session and terminal titles after the August rollout will notice their sessions reverting to generic names after upgrading to v2.25.1, unless they add the config flag. It's a reminder that recently introduced conveniences in Mistral Vibe can have their defaults tuned quickly based on real-world cost or feedback, and it's worth checking config after an upgrade if a familiar feature suddenly seems to have disappeared.