Mistral-Medium-3.5-128B

Mistral Medium 3.5 128B Mistral Medium 3.5 is our first flagship merged model. It is a dense 128B model with a 256k context window, handling instruction-following, reasoning, and coding in a single set of weights. Mistral Medium 3.5 replaces its predecessor Mistral Medium 3.1 and Magistral in Le Chat. It also replaces Devstral 2 in our coding agent Vibe. Concretely, expect better performance for instruct, reasoning and coding tasks in a new unified model in comparison with our previous released models. Reasoning effort is configurable per request, so the same model can answer a quick chat reply or work through a complex agentic run. We trained the vision encoder from scratch to handle variable image sizes and aspect ratios. Find more information on our blog. [!Note] To speed up local inference using vLLM or SGLang, check out our released EAGLE model. [!Warning] The Transformers config originally had an incorrect entry that caused long-context performance degradation. This has been fixed in this commit. GGUFs generated using the Transformers config prior to this commit are also affected. Please use the correct config for best performance. Key Features Mistral Medium 3.5 includes the following architectural choices: **Dense 128B parameters**. **256k context length**. **Multimodal input**: Accepts both text and image input, with text output. **Instruct and Reasoning functionalities** with function calls (reasoning effort configurable per request). Mistral Medium 3.5 offers the following capabilities: **Reasoning Mode**: Toggle between fast instant reply mode and reasoning mode, boosting performance with test-time compute when requested. **Vision**: Analyzes images and provides insights based on visual content, in addition to text. **Multilingual**: Supports dozens of languages, including English, French, Spanish, German, Italian, Portuguese, Dutch, Chinese, Japanese, Korean, and Arabic. **System Prompt**: Strong adherence and support for system prompts. **Agentic**: Be