# GPT 5.3 Codex (Fast)

GPT-5.3-Codex advances both the frontier coding performance of GPT‑5.2-Codex and the reasoning and professional knowledge capabilities of GPT‑5.2, together in one model, which is also 25% faster. This enables it to take on long-running tasks that involve research, tool use, and complex execution.

- **Model ID:** `openai/gpt-5.3-codex-fast`
- **Type:** chat
- **Providers:** openai
- **Context window:** 400,000
- **Maximum output tokens:** 128,000
- **Pricing:** $3.5/1M input tokens, $28/1M output tokens
- **Canonical page:** https://vercel.com/ai-gateway/models/gpt-5.3-codex-fast

## Supported parameters

Detailed capability metadata has not been reported for this model.

## Example

```ts
import { streamText } from 'ai'

const result = streamText({
  model: 'openai/gpt-5.3-codex-fast',
  prompt: 'Why is the sky blue?'
})
```

## Links

- [Model page](https://vercel.com/ai-gateway/models/gpt-5.3-codex-fast)
- [AI Gateway documentation](https://vercel.com/docs/ai-gateway)
- [Provider model documentation](https://openai.com/index/introducing-gpt-5-3-codex/)
- [Provider pricing](https://openai.com/api/pricing/)


If you encounter incorrect information, can’t find what you need, need a capability Vercel doesn’t currently offer, or have any other feedback to report, please do it by following the instructions at https://vercel.com/feedback.md.