DeepSeek releases DeepSeek-V3.1 with hybrid thinking
Released DeepSeek-V3.1 — one model switching between Think and Non-Think modes, 671B total / 37B active, 128K context, 840B tokens of long-context continued pretraining on top of V3, MIT
Why it matters
Billed by DeepSeek as its first step toward the agent era; the API's deepseek-chat and deepseek-reasoner became the non-thinking and thinking modes of one model, merging what had been separate V3 and R1 offerings
Source — Primary sources first; secondary reports are labelled “Press”
Officialdeepseek.comhttps://deepseek.com/en/news/deepseek-v3-1Added in Week 41, 2026 · See that week