Devstral is Mistral AI's family of coding models built for software engineering agents that fix real issues across whole codebases.
In plain words
Many coding models are good at single functions but struggle with real projects, where a fix can touch several files. Devstral, built with All Hands AI and released in May 2025 under Apache 2.0, targets that agent work and led open models on the SWE-Bench Verified test at launch. Devstral 2 followed in December 2025 in 123-billion and 24-billion-parameter sizes. Mistral has since retired the Devstral 2 API models and points users to Mistral Medium 3.5.
A quick example
Imagine an agent given a bug report from a GitHub issue. Using Devstral, it searches the repository, edits the relevant files, runs the tests and proposes a fix.
Where you'll meet it
- Coding agents that work across a repository.
- Local coding assistants using the open weights.
Related
Sources
- DocsDevstral, Mistral AI · read 5 Oct 2026
- DocsIntroducing Devstral 2 and Mistral Vibe CLI, Mistral AI · read 12 Oct 2026
- DocsModels overview, Mistral AI docs · read 5 Oct 2026
Checked by WhatIsAI against the sources above · 12 Oct 2026. Spotted an error? Report it.