Leanstral 1.5
mistral/leanstral-1.5An updated Lean 4 formal proof engineering model optimised for automated theorem proving and autoformalization. 119B total parameters, 6.5B active.
Context
262K
262,144 tokens
Max output
128K
128,000 tokens
Input
Free
per 1M tokens
Output
Free
per 1M tokens
Providers
1
1 listings
Intelligence
—
Not yet scored
Pricing
USD per 1M tokens · listed by Mistral
| Token type | Standard |
|---|---|
| Input | Free |
| Output | Free |
Lowest input price across providers: Free.
Capabilities
ReasoningYes
Effort: none, high
Tool callYes
Structured outputYes
TemperatureYes
AttachmentsYes
Interleaved reasoningNo
Open weightsYes
ModeratedUnknown
Input
TextImage
Output
Text
Benchmarks
Published scores and Design Arena Elo
No published benchmark scores for this model yet.
Rankings
Position on each OneAtlas leaderboard
Providers · 1
1 listings
| Provider | Model ID | Context | Input limit | Output | Input $ | Output $ | Reasoning $ | Cache read | Cache write | Audio in | Audio out | Reasoning | Tools | Structured | Temp. | Updated |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mistral | labs-leanstral-1-5-1 | 262K | — | 128K | Free | Free | — | — | — | — | — | Yes | Yes | Yes | Yes | Jun 30, 2026 |