GPT-5 has a hidden system prompt
simonwillison.net
GPT-5 has a hidden system prompt
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Re: GPT-5 has a hidden system prompt
#2Of course it does. Do you really think you have full control over API output? Do you really think "the system prompt you can specify in an API call" is the system prompt and not the developer instructions prompt?
Re: GPT-5 has a hidden system prompt
#3Of course it does. Do you really think you have full control over API output? Do you really think "the system prompt you can specify in an API call" is the system prompt and not the developer instructions prompt?
I think the definitive point is that it should be documented. Security through obscurity all by itself isn't security.