# GPT 5\.3 Codex is now on AI Gateway

**Published:** February 24, 2026 | **Authors:** Walter Korman, Jerilyn Zheng

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GPT 5.3 Codex is now available on AI Gateway. GPT 5.3 Codex brings together the coding strengths of GPT-5.2-Codex and the reasoning depth of GPT-5.2 in a single model that's 25% faster and more token-efficient.

Built for long-running agentic work, the model handles research, tool use, and multi-step execution across the full software lifecycle, from debugging and deployment to product documents and data analysis. Additionally, you can steer it mid-task without losing context. For web development, it better understands underspecified prompts and defaults to more functional, production-ready output.

To use this model, set model to `openai/gpt-5.3-codex` in the AI SDK.

```tsx
import { streamText } from 'ai';
const result = streamText({
  model: 'openai/gpt-5.3-codex',
  prompt:
    `Research our current API architecture, identify performance
     bottlenecks, refactor the slow endpoints, add monitoring,
     and deploy the changes to staging.`,
});
```

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](https://vercel.com/docs/observability/ai-sdk-observability), [Bring Your Own Key](https://vercel.com/docs/ai-gateway#bring-your-own-key) support, and intelligent provider routing with automatic retries.

Learn more about [AI Gateway](https://vercel.com/ai-gateway), view the [AI Gateway model leaderboard](https://vercel.com/ai-gateway/leaderboards) or try it in our [model playground](https://vercel.com/ai-gateway/models/gpt-5.3-codex).

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📚 **More updates:** [View all changelog entries](/changelog/sitemap.md) | [Blog](/blog/sitemap.md)