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    OpenAI: GPT-5.1-Codex-Max

    openai/gpt-5.1-codex-max

    Created Dec 4, 2025400,000 context
    $1.25/M input tokens$10/M output tokens

    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. GPT-5.1-Codex-Max delivers faster performance, improved reasoning, and higher token efficiency across the development lifecycle.

    Providers for GPT-5.1-Codex-Max

    OpenRouter routes requests to the best providers that are able to handle your prompt size and parameters, with fallbacks to maximize uptime.