GPT 5.3 Codex is now on AI Gateway

Source: Vercel Blog

GPT 5.3 Codex is now 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. You can also steer it mid‑task without losing context. For web development, it better understands underspecified prompts and defaults to more functional, production‑ready output.

Using the model

Set the model to openai/gpt-5.3-codex in the AI SDK:

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 features

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
• Intelligent provider routing with automatic retries

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