Deadline · source dated 24 Apr · checked 22 Jul
At the 22 July check, two days remained before DeepSeek’s scheduled legacy-ID cutoff.
DeepSeek’s official API change log said deepseek-chat and deepseek-reasoner would be discontinued on 24 July 2026. During the documented transition, those names pointed to the non-thinking and thinking modes of deepseek-v4-flash.
This was an application-contract change, not merely a naming cleanup. The recorded action was to inspect hard-coded IDs, gateway aliases, fallback chains, monitoring labels, cost attribution, and tests that treated the two legacy names as separate model families. A request succeeding at that checkpoint did not prove that the application had migrated to the supported contract.