In late July 2025, developers inspecting OpenAI’s ChatGPT Agent macOS application uncovered references to two previously unannounced models—GPT-5-Auto and GPT-5-Reasoning—suggesting that the next-generation GPT-5 system has entered an internal testing phase. Configuration files buried in the app’s cache include entries like “gpt-5-reasoning-alpha-2025-07-13” with a parameter “reasoning_effort: high”, indicating a specialized focus on intensive, multi-step reasoning […]