DeepSeek V4.1 Flash API

Quick start

Set API_KEY to your project key, then run a sample from your server. Replace example media URLs with your own public URLs.

Auto-routing chooses a provider that supports the request. Select a provider to see its input constraints and pinned request examples.

curl https://01router.com/api/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek-v4.1-flash",
    "messages": [{ "role": "user", "content": "Hello!" }],
    "stream": false
  }'

Endpoints

Only endpoints relevant to this model are listed. Paths below include /api/v1. Click an endpoint to read its usage.

Authentication

Send your API key as a Bearer token. Requests are billed to the key owner's credits.

Authorization: Bearer YOUR_API_KEY
Content-Type: application/json

Input

Send messages directly in the request body. Chat requests do not use an input wrapper.

Request body

Output

This example uses stream: false. Read the reply from choices[0].message.content. With stream: true, read SSE chunks from choices[].delta until [DONE].

Task completed

{
  "id": "chatcmpl-example",
  "object": "chat.completion",
  "model": "deepseek-v4.1-flash",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello! How can I help?"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 9,
    "completion_tokens": 8,
    "total_tokens": 17
  }
}

Response fields

Model schema

This public endpoint returns the model parameters and each provider’s supported constraints and prices.

curl "https://01router.com/api/v1/models/deepseek-v4.1-flash"

Errors

Check the HTTP status and error.message. Fix the request before retrying validation or authentication errors. A failed generation is reported in status and error on the task itself.

{
  "error": {
    "message": "Invalid or missing API key",
    "code": "unauthorized"
  }
}

Use with AI

Give your coding assistant this model reference: endpoints, input constraints, output fields and request examples in plain text.