Deadline · source dated 24 Apr · checked 22 Jul
Two days remain before DeepSeek’s legacy model IDs are scheduled to end.
DeepSeek’s official API change log says deepseek-chat and deepseek-reasoner will be discontinued on 24 July 2026. During the transition, those names point to the non-thinking and thinking modes of deepseek-v4-flash.
This is an application-contract change, not merely a naming cleanup. Teams should inspect hard-coded IDs, gateway aliases, fallback chains, monitoring labels, cost attribution, and tests that assume the two legacy names identify separate model families. A request returning successfully today does not prove that the application has migrated to the supported contract.