OpenAI restores 272K context windows in Codex

OpenAI restored full 272K-token context windows to GPT-5.6 Sol, Terra, and Luna in Codex on July 18, per its release notes.

If you benchmarked those three models in Codex over the past few weeks, you may have graded a bug, not the model. The release notes bundle the fix with other changes and don't say how long the window had been running short.

A 272K context window is a specific, testable number. When it quietly shrinks, everything measured against it shifts too. Any claim about how well Sol, Terra, or Luna handle long documents or big repos was measuring degraded infrastructure, not the model's real ceiling. OpenAI's notes don't say what caused the shrink or whether it hit every Codex user the same way.

Without a disclosed start date, there's no way to know which past runs on Sol, Terra, or Luna hit the truncated window. The safest move is rerunning any long-context eval from before July 18.