GPT-5.1-Codex-Max
OpenAI
openai/gpt-5.1-codex-maxGPT-5.1-Codex-Max is OpenAI's frontier agentic coding model, using a compaction technique to coherently work across millions of tokens in a single task. It targets project-scale refactors, extended debugging sessions, and multi-hour autonomous coding loops.
Cost rate
2x
Context
400K
Released
Dec 4, 2025
Input
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Output
Text
Support
ReasoningTool callingStructured outputs
Best at
The categories where this model ranks highest.