LLM Reference
OpenRouter

Using GPT-5.1 Codex Max on OpenRouter

Implementation guide · GPT-5.1 · OpenAI

Serverless

OpenRouter exposes GPT-5.1 Codex Max through model ID openai/gpt-5.1-codex-max. Use the setup steps, sourced pricing, capabilities, and official provider links below to validate this route before deployment.

Last refreshed 2026-06-15. Next refresh: weekly.

Quick Start

  1. 1
    Create an account at OpenRouter and generate an API key.
  2. 2
    Use the OpenRouter SDK or REST API to call openai/gpt-5.1-codex-max — see the documentation for request format.
  3. 3
    You'll be billed $1.25/1M input, $10.00/1M output tokens. See full pricing.
API PortalDocumentationPricingModel Card

Code Examples

See OpenRouter documentation for integration details.

Pricing on OpenRouter

TypePrice (per 1M)
Input tokens$1.25
Output tokens$10.00

Capabilities

VisionMultimodalReasoningJSON / Tool useStructured Outputs

About GPT-5.1 Codex Max

OpenAI's GPT-5.1-Codex-Max is a code-specialized model released November 19, 2025, optimized for agentic coding tasks including project-scale refactors, debugging, and multi-file edits. Uses context compaction to handle long-running tasks beyond a single context window. 30% more token-efficient than previous Codex on SWE-bench. Supports an extra-high reasoning effort option.

Full model details →

Model Specs

Released2025-11-19
Knowledge cutoff2024-09

More Models on OpenRouter

GPT-5.1GPT-5.1 CodexGPT-5.1 ChatGPT-5.1 Codex Mini
All models on OpenRouter →

Also available on(2)

Vercel AI Gateway$1.25/1MOpenAI API$1.25/1M
Compare all providers →

Provider

OpenRouter
OpenRouter

OpenRouter, Inc.

New York, NY, USA