Does gpt 5.4 not support "stop" sequences with the chat.completions api?
OpenAI Developer Community
April 1, 2026
I’m aware, which is why I don’t understand why it doesn’t work for the 5.x models? It works perfectly fine for the old 4o model, but not for 5.4 (getting the “400 Unsupported parameter: ‘stop’ is not supported with this model”
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