> ## Documentation Index
> Fetch the complete documentation index at: https://docs.unifically.com/llms.txt
> Use this file to discover all available pages before exploring further.

# DeepSeek V4.1 Flash

> DeepSeek's DeepSeek V4.1 Flash language model. See supported inputs, parameters, pricing, response fields, and API examples.

DeepSeek V4.1 Flash is DeepSeek's September 2026 Flash model for agentic coding and long-context work, with a 1M-token context window, 384K max output, and thinking on by default. The `deepseek/deepseek-flash` ID always points at DeepSeek's latest Flash model.

## Model

```
deepseek/deepseek-flash
```

|              |                     |
| ------------ | ------------------- |
| **Provider** | DeepSeek            |
| **Name**     | DeepSeek V4.1 Flash |

## Supported Endpoints

All three API formats are supported:

* [Chat Completions](/api-reference/v1-chat-completions) — `POST /v1/chat/completions`
* [Responses](/api-reference/v1-responses) — `POST /v1/responses`
* [Messages](/api-reference/v1-messages) — `POST /v1/messages`

<Info>
  DeepSeek models bill at 2x during peak hours: Monday to Friday, 01:00–04:00 and 06:00–10:00 UTC. The rate is fixed when the request starts. See [pricing](https://unifically.com/pricing) for current rates.
</Info>

## Example

```bash theme={null}
curl -X POST https://api.unifically.com/v1/chat/completions   -H "Content-Type: application/json"   -H "Authorization: Bearer YOUR_API_KEY"   -d '{
    "model": "deepseek/deepseek-flash",
    "messages": [
      {"role": "user", "content": "Refactor this function to be more testable."}
    ]
  }'
```

<Note>
  **Volume discounts** are available for almost all models. Reach out at [contact@unifically.com](mailto:contact@unifically.com) to discuss custom pricing.
</Note>