You can now access OpenAI's latest Codex models, GPT-5.1 Codex and GPT-5.1 Codex mini with Vercel's AI Gateway and no other provider accounts required. These Codex models are optimized for long-running, agentic coding tasks and are able to maintain context and reasoning over longer sessions without degradation.

To use these models with the AI SDK, set the model to openai/gpt-5.1-codex or openai/gpt-5.1-codex-mini:

import { streamText } from 'ai';
const result = streamText({
  model: 'openai/gpt-5.1-codex',
  prompt:
    `Create a command-line tool that reads a text file,
     counts word frequencies, and prints the ten most common
     words with counts. Use standard libraries only.`
});

AI Gateway provides a unified API for calling models, tracking usage and cost, and configuring retries, failover, and performance optimizations for higher-than-provider uptime. It includes built-in observability, Bring Your Own Key support, and intelligent provider routing with automatic retries.

Learn more about AI Gateway, view the AI Gateway model leaderboard or try it in our model playground.