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...
OpenAI: GPT-5.1-Codex-Max — OpenAI. Context window 400,000 tokens. API pricing (per 1M tokens): Input $1.25, Output $10. License: Proprietary.
| Provider | OpenAI |
|---|---|
| API model ID | openai/gpt-5.1-codex-max |
| Tier | Frontier |
| Context window | 400,000 tokens |
| Max output | 128,000 tokens |
| License | Proprietary |
| API pricing (per 1M tokens) · Input | $1.25 |
| API pricing (per 1M tokens) · Output | $10 |