Leanstral 1.5 - Mistral AI
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7. Leanstral 1.5
June 30, 2026
Labs v 1.5
Leanstral 1.5
An updated Lean 4 formal proof engineering model optimised for automated theorem proving and autoformalization. 119B total parameters, 6.5B active.
labs-leanstral-1-5
Speed
Performance
Modalities
Context
i
256k
Price
i
$0
Speed
Performance
Modalities
Context
256k
Price
$0
FEATURES WEIGHTS
Features
Chat Completions /v1/chat/completions
Function Calling /v1/chat/completions/v1/conversations
Agents & Conversations /v1/agents/v1/conversations
Built-In Tools /v1/agents/v1/conversations
Structured Outputs /v1/chat/completions/v1/conversations
Predicted Outputs /v1/chat/completions/v1/conversations
Prefix /v1/chat/completions/v1/conversations
Annotations - Structured /v1/ocr
Document QnA /v1/chat/completions/v1/conversations
Chat Moderations /v1/chat/moderations
Transcriptions /v1/audio/transcriptions
Text to Speech /v1/audio/speech
Timestamps /v1/audio/transcriptions
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