Tested on Mistral Vibe v2.26.0 using vibe --yolo --experimental-harness. Everything below uses the documented configuration surface (the same one the CLI's built-in /config browser and skill docs describe), so it should keep working on later releases — no patching, no rebase pain.
Mistral Large 4 (mistral-large-4-0, public preview, released 6 October 2026) is served on the Mistral API — but if you fire up Mistral Vibe and hit /model, it's not in the picker. The CLI ships a small, curated default model catalog, and Large 4 simply isn't in it yet.
The tempting move is to fork the repo and append the model to the hardcoded DEFAULT_MODELS list. Don't. You don't need any custom code: Vibe's configuration is layered, the models list union-merges with the built-ins by alias, and the stock mistral provider already points at https://api.mistral.ai/v1 using MISTRAL_API_KEY — which is exactly where Large 4 is s