OpenAI: GPT-5.1-Codex-Max

GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks. It is based on an updated version of the 5.1 reasoning stack and trained on agentic...

ProviderPlanEst. / monthIncludedSource date
OpenAIstandard$12.50—2026-09-18