Mistral Medium 3.5

Mistral's first merged flagship: 128B dense, single set of weights folding instruction following, reasoning, and coding into one model. Replaces the prior Magistral / Devstral 2 split. 256K context. Configurable reasoning-effort setting. Trained-from-scratch vision encoder handling variable image sizes and aspect ratios. Released April 29, 2026 under a modified MIT license, open weights, runs on 4 GPUs.

AA Intelligence Index: 39 — Mistral's highest to date and well above the open-weight median of 15. 77.6% on SWE-Bench Verified. Powers the Vibe remote agents (async cloud coding from CLI or Le Chat) and Le Chat's new Work mode.