Mistral AI·· 2026-03-17
Leanstral: Open-Source foundation for trustworthy vibe-coding
Leanstral: Open-Source foundation for trustworthy vibe-coding
AI summary
Mistral AI released Leanstral, the first open-source coding agent for Lean 4, using a sparse architecture with 6B active parameters. Its weights are available under Apache 2.0, and it is integrated into Mistral vibe and the free labs-leanstral-2603 API endpoint.
Selection record
Threshold 60Official, first-handFirst 58Second 62
AdmittedSum of both 120 ≥ twice the threshold 120
- Source tier
- Official, first-hand; this tier's threshold is 60
- Pre-filter
- passed：发布开源代码AI智能体Leanstral及评测
- Why it was chosen
- Cost and score comparisons with Claude models and open-source alternatives help assess the value of formal verification approaches.
A model scores each item twice, independently, against one written standard, out of 100. An item is admitted only when the two scores add up to twice the threshold. The threshold is set per source tier.
Source: Mistral AI · mistral.ai