Mistral AI Retirement

Leanstral 1.5’s hosted preview is scheduled to retire.

The September 30 notice concerns labs-leanstral-1-5. It does not establish a change to open-weight rights.

Documentation reviewed · No live product test

The next move

Check whether you depend on the hosted preview or run downloaded weights yourself.

What the vendor says

Mistral’s June 30 release entry states that labs-leanstral-1-5 will retire on September 30, 2026. The entry names no successor.

Sources: Mistral API changelog · Leanstral 1.5 model documentation

Why it matters

A hosted preview dependency needs its own continuity plan. Downloaded weights and hosted API access are different dependencies.

AI-Buzz suggested checks

Turn the notice into a task.

  1. Locate labs-leanstral-1-5 in API configuration and request logs.
  2. Separate hosted calls from any locally deployed model; this notice alone does not establish a local migration requirement.
  3. For hosted use, confirm a supported destination with Mistral and test your proof or coding workflow before changing configuration.

What this does not establish

The original retirement-announcement date is unknown. A dated, mutable release entry does not show when retirement wording was added. No inference about weight licensing follows from this API notice.

Read the original sources

AI-Buzz checked these pages on 9 Sept 2026. This is our reading on that date. The linked pages can change; we do not reconstruct earlier versions from today’s text.

  1. Mistral API changelog June 30, 2026 Leanstral 1.5 entry
    Review receipt
    Retrieved
    2026-09-09T11:11:21.547819Z
    Response SHA-256
    036e162a06ffbead3b0dbeaefba844d11dc6c2c25c47e565ae8fa39fb523ddbd

    Manual review. Full source bytes were not retained. A hash cannot recover the page or establish when its wording changed.

  2. Leanstral 1.5 model documentation Hosted public preview, release date and model availability
    Review receipt
    Retrieved
    2026-09-09T11:11:21.589455Z
    Response SHA-256
    cb56a8ec67de631301884fa3d1dbb3a6729c97ceeedc6cd5484ed9061681237b

    Manual review. Full source bytes were not retained. A hash cannot recover the page or establish when its wording changed.

Evidence and correction policy