Devstral Small 1.0
Devstral Small 1.0 is a 24B software-engineering model developed by Mistral and All Hands AI. It is fine-tuned from Mistral Small 3.1 for tool-based work on code repositories.
Why it is text-only
The developers removed the parent model’s vision encoder before coding-agent fine-tuning. The release keeps a 128K context window and a Tekken vocabulary of about 131K tokens. It can inspect repository text, but this checkpoint does not retain Small 3.1 image input.Devstral Small 1.0 official model card
Evaluation with OpenHands
Mistral reports 46.8% on SWE-bench Verified with the OpenHands environment. The card recommends that environment and provides local and API configuration examples. This result describes the model working with that agent setup, rather than the language model in isolation.Devstral Small 1.0 official model card
Specifications & access
| Detail | Value and conditions |
|---|---|
| Launch date | |
| Access | Downloadable |
| Model identifiers | Devstral-Small-2505devstral-small-2505 |
| Context window | 128,000 tokens The model catalog advertises 128k context for this version. This is not a measured recall limit. Devstral Small 1.0 model and lifecycle record |
| Weight license | Apache 2.0Devstral Small 1.0 official model card |
| Access and lifecycle | Hosted API retired on 30 November 2025. Downloadable weights remain listed.Devstral Small 1.0 model and lifecycle recordDevstral Small 1.0 official model card |
| Parameters | 24 billionDevstral Small 1.0 official model card |