Mistral

Leanstral 1.5

Name: Leanstral 1.5
Brand: Mistral

Canonical ID: mistral/labs-leanstral-1-5-1

More Mistral models More leanstral family models

An updated Lean 4 formal proof engineering model optimised for automated theorem proving and autoformalization. 119B total parameters, 6.5B active.

Reasoning: Yes Tool use: Yes Open weights

Overview

text image

Provider: Mistral
Family: leanstral
Release date: 2026-06-30
Last updated: 2026-06-30
Input modalities: text, image
Output modalities: text

Pricing and Limits

Token pricing

Input: $0/1M
Output: $0/1M
Cached input: N/A

Context and output

Context window: 262,144
Max output tokens: 128,000
Qualified ID: mistral/labs-leanstral-1-5-1

Model Summary

Leanstral 1.5 is a model listing in the Mistral provider catalog. It is categorized under the leanstral family.

The model supports text, image modalities across input/output paths. Reported context capacity is 262,144. Pricing is listed at $0/1M input and $0/1M output.

Same Family: leanstral

Comparable models in the same family across providers.

Browse family

Model	Provider	Context	Input	Output	Flags
leanstral-1-5 requesty/leanstral-1-5	Requesty	262,144	$0/1M	$0/1M	Tools
leanstral-1-5@eu requesty/leanstral-1-5@eu	Requesty	262,144	$0/1M	$0/1M	Tools

Leanstral 1.5

Overview

Pricing and Limits

Token pricing

Context and output

Model Summary

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