OpenAI serves gpt-5.6-luna for gpt-6-astra requests on Pro 20x

· Community Openai · Sept. 21, 2026, 12:54 a.m.
Summary
The blog post presents evidence suggesting that the model being served (gpt-5.6-luna) may not correspond with the model requested (gpt-6-astra) during API interactions with OpenAI's Codex. The author details specific server responses, request behaviors, and their observations over a significant period, implying that server-side decisions affect which model is served regardless of user choices or client-side settings. This raises concerns about transparency and accuracy in API responses.
AUTHOR