Mistral Medium 3.5

Mistral Medium 3.5 is a 128B dense language model that unifies instruction-following, reasoning, and coding in a single set of weights. It features a 256k context window and configurable reasoning effort, making it suitable for complex, long-running tasks. The model achieves 77.6% on SWE-Bench Verified and is available as open weights on Hugging Face, empowering engineers to run self-hosted inference.