GPT-5.1-Codex-Max
OpenAI
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...
What is 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...
Specifications
- Developer: OpenAI
- Context window: 400K tokens
- Max output: 128K tokens
- Input modalities: text, image
- Output modalities: text
- Input price: $1.25 per 1M tokens
- Output price: $10.00 per 1M tokens
- Knowledge cutoff: —
- Supported parameters: include_reasoning, max_completion_tokens, max_tokens, reasoning, response_format, seed, structured_outputs, tool_choice, tools
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