# DeepSeek V4.1 Flash 1017 Ultrafast

DeepSeek V4.1 Flash 1017 Ultrafast serves the October 17, 2026 update of DeepSeek V4.1 Flash through Fireworks' accelerated serverless endpoint. It supports text and image input, configurable reasoning, tool calling, structured outputs, and automatic prefix caching. Available in public preview without a waitroom or session time limit.

- **Model ID:** `deepseek/deepseek-v4.1-flash-1017-ultrafast`
- **Type:** chat
- **Providers:** fireworks
- **Context window:** 1,048,576
- **Maximum output tokens:** 1,048,576
- **Pricing:** $2.40/1M input tokens, $9.60/1M output tokens
- **Canonical page:** https://vercel.com/ai-gateway/models/deepseek-v4.1-flash-1017-ultrafast

## Supported parameters

Detailed capability metadata has not been reported for this model.

## Example

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

const result = streamText({
  model: 'deepseek/deepseek-v4.1-flash-1017-ultrafast',
  prompt: 'Why is the sky blue?'
})
```

## Links

- [Model page](https://vercel.com/ai-gateway/models/deepseek-v4.1-flash-1017-ultrafast)
- [AI Gateway documentation](https://vercel.com/docs/ai-gateway)
- [Provider model documentation](https://fireworks.ai/models/fireworks/deepseek-v4p1-flash-1017)
- [Provider pricing](https://fireworks.ai/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.