OpenAI API exposes GPT-5.1 Codex Max through model ID 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 2026-06-04. Next refresh: weekly.
Quick Start
- 1
- 2Use the OpenAI API SDK or REST API to call
gpt-5.1-codex-max— see the documentation for request format. - 3
Code Examples
Install
pip install openaiAPI key
OPENAI_API_KEYModel ID
gpt-5.1-codex-maxUse the model slug directly, e.g. "gpt-4o" or "gpt-4.1-mini".
import os
from openai import OpenAI
client = OpenAI() # reads OPENAI_API_KEY from env
response = client.chat.completions.create(
model="gpt-5.1-codex-max",
messages=[{"role": "user", "content": "Hello"}]
)
print(response.choices[0].message.content)Pricing on OpenAI API
| Type | Price (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.
Model Specs
Released2025-11-19
Knowledge cutoff2024-09