Dev Tools · 2h ago
DeepSeek V4 API Not OpenAI Compatible; Reasoning Field Often Missed
DeepSeek's V4 API uses /chat/completions, not OpenAI's /responses endpoint. Developers who assume compatibility may lose the reasoning_content field, which contains the model's thinking output. Old model names deepseek-chat and deepseek-reasoner are deprecated as of July 2026.
Meridian48 take
The warning is valid but narrow; most developers using standard OpenAI SDKs will still work, but those relying on the newer Responses API need explicit handling.
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DeepSeek's Response API Isn't OpenAI Responses. That One Parser Mistake Drops the Reasoning. →
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deepseek-apiopenai-compatibility