DeepSeek v4 API

Complete API reference for DeepSeek v4 LLM models powered by DeepSeek.

Model Updates

DeepSeek v4 Flash 0731

• Flaq AI has updated DeepSeek v4 Flash to DeepSeek's official deepseek-v4-flash-0731 release.
• Use the 0731 model IDs below to access the updated version.
• The original model IDs remain available for existing API integrations.

Model Variants

This API supports four DeepSeek v4 model variants:

Quick Comparison

DeepSeek v4 Pro Text to Text

Endpoint

httpCopy
POST /api/v1/chat/completions

Request Parameters

Required

Message Support

Optional

Example Request

javascriptCopy
const response = await fetch('https://api.flaq.ai/api/v1/chat/completions', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Accept': 'text/event-stream',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    model: 'deepseek-v4-pro-text-to-text',
    messages: [
      {
        role: 'user',
        content: 'Hello'
      }
    ],
    stream: true,
    max_tokens: 500,
    top_p: 0.5,
    top_k: 1
  })
});

DeepSeek v4 Flash Text to Text

Endpoint

httpCopy
POST /api/v1/chat/completions

Request Parameters

Required

Message Support

Optional

Example Request

javascriptCopy
const response = await fetch('https://api.flaq.ai/api/v1/chat/completions', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Accept': 'application/json',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    model: 'deepseek-v4-flash-text-to-text',
    messages: [
      {
        role: 'user',
        content: 'Write a four-line modern poem about a programmer drinking coffee.'
      }
    ],
    stream: false,
    max_tokens: 500,
    top_p: 0.5,
    top_k: 1
  })
});

DeepSeek v4 Pro Web Search

Endpoint

httpCopy
POST /api/v1/chat/completions

Request Parameters

Required

Message Support

Optional

Example Request

javascriptCopy
const response = await fetch('https://api.flaq.ai/api/v1/chat/completions', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Accept': 'text/event-stream',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    model: 'deepseek-v4-pro-web-search',
    messages: [
      {
        role: 'user',
        content: 'What date is it today?'
      }
    ],
    stream: true,
    max_tokens: 500,
    top_p: 0.5,
    top_k: 1
  })
});

DeepSeek v4 Flash Web Search

Endpoint

httpCopy
POST /api/v1/chat/completions

Request Parameters

Required

Message Support

Optional

Example Request

javascriptCopy
const response = await fetch('https://api.flaq.ai/api/v1/chat/completions', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Accept': 'text/event-stream',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    model: 'deepseek-v4-flash-web-search',
    messages: [
      {
        role: 'user',
        content: 'What date is it today?'
      }
    ],
    stream: true,
    max_tokens: 500,
    top_p: 0.5,
    top_k: 1
  })
});

Response Format

DeepSeek V4 LLM models return OpenAI-compatible completion responses. With stream: true, the response is Server-Sent Events; with stream: false, the response is a single JSON object.

Error Response

jsonCopy
{
  "error": {
    "code": "1001",
    "param": null,
    "message": "Authorization is empty",
    "type": "invalid_request_error"
  }
}

Best Practices

1. Choose the right variant: Use Pro models for higher-quality reasoning and Flash models for lower-latency, lower-cost workloads.
2. Use Web Search for current events: Choose Pro or Flash Web Search when the answer depends on up-to-date online information.
3. Tune sampling parameters carefully: top_p and top_k are supported across all DeepSeek v4 variants and can change output diversity.
4. Send only supported inputs: Do not send file or image parts to any DeepSeek v4 route.
5. Match Accept with stream mode: Use Accept: text/event-stream for streaming requests and Accept: application/json for non-streaming requests.