leanstral-1-5
leanstral-1-5
Leanstral 1.5 is an updated Lean 4 formal proof engineering model from Mistral AI, optimized for automated theorem proving and autoformalization. It has 119B total parameters with 6.5B active and supports a 256K token context window. It supports native function calling and structured output.
Specification
most-agreed values
Context
262K
Max output
33K
Released
2026-05-27
Knowledge cutoff
—
Retires
—
Open weights
no
Input
text
Output
text
Price
US dollars per million tokens · most-agreed
Input
free
Output
free
Available from 1 host
| Host | In $/M | Out $/M | Cache rd | Cache wr | Context | Output | Retires |
|---|---|---|---|---|---|---|---|
| requesty | free | free | — | — | 262K | 33K | — |