Codex users report GPT-5.5 reasoning tokens clustering at 516, linked to weaker answers

A GitHub issue analyzing Codex token metadata from February 1 to June 27, 2026 found gpt-5.5 responses landing disproportionately at exactly 516 reasoning tokens, consistent with a reasoning-budget threshold. The author says it does not prove truncation. The thread drew 372 points and 152 comments.

Who is affected:

Codex users running gpt-5.5 on complex tasks.

What to do:

No action needed. GPT-5.5 retired from Codex with ChatGPT sign-in on October 14, 2026.