ChatGPT in Xcode provides two model choices. “GPT-5” is
optimized for quick, high-quality results, and should work well
for most coding tasks. For difficult tasks, choose “GPT-5
(Reasoning)“, which spends more time thinking before responding,
and can provide more accurate results for complex coding tasks.
In the OpenAI API, “GPT-5” corresponds to the “minimal”
reasoning level, and “GPT-5 (Reasoning)” corresponds to the
“low” reasoning level. (159135374)