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 workflows spanning software engineering, mathematics, and research.
Input
Output
Context
400K
Max Output
128K
Parameters
—
Technical Specifications
Model TypeChat
Context Window400K
Max Output Tokens128K
Parameters—
Training Cutoff—
Licenseproprietary
Capabilities
Input Modalities
textimage
Output Modalities
text
Features
agenticcode_completioncode_generationcode_reviewextended_thinkingfunction_callingjson_modestreamingtool_usevision
Resources & Links
proprietary — Proprietary - API access only
Related Tools
Data sourced from official provider APIs and documentation
Last updated: May 5, 2026
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