DeepSeek V3.1 Terminus

DeepSeek-V3.1 Terminus, released in September 2025, refines V3.1 with targeted production-stability improvements. The 671-billion-parameter model keeps 37 billion active parameters and a 128K-token context while addressing the language-consistency and tool-use issues users reported. The update reduces Chinese-English code-mixing and stray-character generation seen in earlier versions, producing more reliable multilingual output. DeepSeek also reports stronger Code Agent and Search Agent behavior, making Terminus a steadier choice for multi-tool agentic workflows. It retains the hybrid thinking and non-thinking modes of V3.1 and is available with open weights on Hugging Face, aimed at deployments that need robust, predictable multilingual performance.