Gpt-chat-latest does not support json_schema

API
1

I am getting this error, when trying to use gpt-chat-latest in combination with a json_schema via the responses API:

400 Invalid parameter: ‘text.format’ of type ‘json_schema’ is not supported with model version gpt-chat-latest-2026-05-05.

The exact same code works fine with gpt-5.2-chat.

I can see no documentation, which states that support for json_schema has been removed from gpt-chat-latest. Did the syntax for json_schema change? Or any other clues what might be going wrong?

Thanks in advance!

2

Hi and welcome to the community!

The model slug for 5.5-instant is chat-latest . At least I believe that is the model you are trying to call.

3

Oh, my bad. I was accessing the model via Microsoft Azure and they seem to have stripped support for json_schema for some reason. It is working correctly, when I access the model via OpenAI directly.