# GPT 5.6 Luna (Fast)

GPT-5.6 Luna is a fast, affordable GPT-5.6 model that brings strong capability at the lowest cost in the series.

- **Model ID:** `openai/gpt-5.6-luna-fast`
- **Type:** chat
- **Providers:** openai
- **Context window:** 1,050,000
- **Maximum output tokens:** 128,000
- **Pricing:** $0.4/1M input tokens, $2.4/1M output tokens
- **Canonical page:** https://vercel.com/ai-gateway/models/gpt-5.6-luna-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-5.6-luna-fast',
  prompt: 'Why is the sky blue?'
})
```

## Links

- [Model page](https://vercel.com/ai-gateway/models/gpt-5.6-luna-fast)
- [AI Gateway documentation](https://vercel.com/docs/ai-gateway)