Leanstral 1.5

Mistral AI
Model overview

labs-leanstral-1-5

An experimental model for Lean 4 formal theorem proving.

reasoningcodinglong contextevaluationcode generationbenchmark reference
Representative version

labs-leanstral-1-5

CompanyMistral AI
Release2026-06-30
Release typeModel release
ParametersNot disclosed
ArchitectureNot disclosed
Context262,144
Input modalitiestext / code
Output modalitiestext / code
Tool use / function callingNot disclosed
Structured output / reasoningConfirmed: Reasoning
Vision / audio / videoNot disclosed
Open weights / LicenseNo open weights / license not applicable
mistral-leanstral-1-5-current · License not applicable
Vendor APIAvailable
Mistral Docs changelog — June 30mistral-leanstral-1-5-current · 2026-06-30
OpenRouterNot separately listed on OpenRouter
PricingOfficial pricing page
BenchmarkNo reliable public source
Public signalsNo reliable public source
Use casesFormal proof / Lean 4 research / Theorem-proving experiments / research evaluation
Claim evidenceRelease eventMistral Docs changelog — June 30labs-leanstral-1-5 · 2026-06-30
Model specs / weightsLeanstral 1.5 model cardLeanstral 1.5 · labs-leanstral-1-5
OpenRouter

Pricing / context / availability

OpenRouterNot separately listed on OpenRouter
OpenRouter listingNot separately listed in the current OpenRouter public list
Mapped versionlabs-leanstral-1-5
mistral-leanstral-1-5-current
PricingOfficial pricing page
Context262144
Speed/LatencyNo reliable public source
Snapshot time2026-07-15T20:11:41.551Z
SourceView source
Evidence gaps

Public display boundary

Parameter scale not disclosedOpenRouter not separately verifiedNo reliable benchmark sourceNo public model-card activity countersNo linkable real reviewSpeed/latency not disclosed