GPT-5.1 Codex Max API

Access GPT-5.1 Codex Max from OpenAI using Puter.js AI API.

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Model Card

GPT-5.1 Codex Max is OpenAI's frontier agentic coding model built for long-running, detailed work using context compaction. It's the first model trained to operate across multiple context windows coherently.

Context Window N/A

tokens

Max Output 128K

tokens

Input Cost $1.25

per million tokens

Output Cost $10

per million tokens

Release Date Oct 1, 2025

 

API Usage Example

Add GPT-5.1 Codex Max to your app with just a few lines of code.
No API keys, no backend, no configuration required.

// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';

puter.ai.chat("Explain quantum computing in simple terms", {
    model: "openai/gpt-5.1-codex-max"
}).then(response => {
    document.body.innerHTML = response.message.content;
});

<html>
<body>
    <script src="https://js.puter.com/v2/"></script>
    <script>
        puter.ai.chat("Explain quantum computing in simple terms", {
            model: "openai/gpt-5.1-codex-max"
        }).then(response => {
            document.body.innerHTML = response.message.content;
        });
    </script>
</body>
</html>

View full documentation →

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Frequently Asked Questions

What is this GPT-5.1 Codex Max API about?

The GPT-5.1 Codex Max API gives you access to OpenAI's chat model through Puter.js. With just a few lines of JavaScript, you can integrate GPT-5.1 Codex Max into any web app or Node.js project — no API keys, no backend, and no configuration required.

Who created GPT-5.1 Codex Max?

GPT-5.1 Codex Max was created by OpenAI and released on Oct 1, 2025.

What is the max output length of GPT-5.1 Codex Max?

GPT-5.1 Codex Max can generate up to 128K tokens in a single response.

How much does it cost?
The GPT-5.1 Codex Max API is available through the User-Pays Model. As a developer, you can add the GPT-5.1 Codex Max API to your app for free — your users pay for their own AI costs directly.
Price per 1M tokens
Input$1.25
Output$10
How do I access the GPT-5.1 Codex Max API?

You can access the GPT-5.1 Codex Max API with just a few lines of JavaScript — no API keys, no backend, and no configuration required. Include the Puter.js library in your project and start making calls right away. For more details, check out our documentation.

Does the GPT-5.1 Codex Max API work with React / Vue / Vanilla JS / Node / etc.?

Yes — the GPT-5.1 Codex Max API works with any JavaScript framework, Node.js, or plain HTML through Puter.js. Just include the library and start building. See the documentation for more details.

Get started with Puter.js

Add GPT-5.1 Codex Max to your app without worrying about API keys or setup.

Read the Docs View Tutorials