Add Vocals Callbacks

System will call this callback when vocal generation is complete.

When you submit a vocal generation task to the Suno API using the /api/v1/generate/add-vocals endpoint, you can use the callBackUrl parameter to set a callback URL. The system will automatically push the results to your specified address when the task is completed.

Related API Endpoint

This callback is triggered by the following API endpoint:

Add Vocals API

POST /api/v1/generate/add-vocals - Add vocals to uploaded music files

Callback Mechanism Overview

The callback mechanism eliminates the need to poll the API for task status. The system will proactively push task completion results to your server.

Callback Timing

The system will send callback notifications in the following situations:

• Text generation completed (callbackType: “text”)
• First audio track generation completed (callbackType: “first”)
• All audio tracks generation completed (callbackType: “complete”)
• Vocal generation task failed
• Errors occurred during task processing

Callback Method

• HTTP Method: POST
• Content Type: application/json
• Timeout Setting: 15 seconds

Callback Request Format

When the task progresses or completes, the system will send a POST request to your callBackUrl in the following format:

Complete Success Callback

{
  "code": 200,
  "msg": "All generated successfully.",
  "data": {
    "callbackType": "complete",
    "task_id": "2fac****9f72",
    "data": [
      {
        "id": "e231****-****-****-****-****8cadc7dc",
        "audio_url": "https://example.cn/****.mp3",
        "stream_audio_url": "https://example.cn/****",
        "image_url": "https://example.cn/****.jpeg",
        "prompt": "[Verse] Night city lights shining bright",
        "model_name": "chirp-v4-5",
        "title": "Iron Man",
        "createTime": "2025-01-01 00:00:00",
        "duration": 198.44
      }
    ]
  }
}

Status Code Description

Status Code	Description
200	Success - Request has been processed successfully
400	Validation Error - Lyrics contained copyrighted material
408	Rate Limited - Timeout
413	Conflict - Uploaded audio matches existing work of art
500	Server Error - An unexpected error occurred while processing the request
501	Audio generation failed
531	Server Error - Sorry, the generation failed due to an issue. Your credits have been refunded. Please try again

Callback Reception Examples

Here are example codes for receiving callbacks in popular programming languages:

Node.js

const express = require('express');
const app = express();

app.use(express.json());

app.post('/vocals-callback', (req, res) => {
  const { code, msg, data } = req.body;
  
  console.log('Received vocals callback:', {
    taskId: data.task_id,
    status: code,
    message: msg,
    callbackType: data.callbackType
  });
  
  if (code === 200) {
    // Task completed successfully
    if (data.callbackType === 'complete') {
      console.log('Vocals generation completed:', data.data);
      
      // Process generated vocals data
      data.data.forEach(audio => {
        console.log(`Audio ID: ${audio.id}`);
        console.log(`Audio URL: ${audio.audio_url}`);
        console.log(`Title: ${audio.title}`);
        console.log(`Duration: ${audio.duration} seconds`);
      });
      
    } else if (data.callbackType === 'first') {
      console.log('First track completed');
      
    } else if (data.callbackType === 'text') {
      console.log('Text generation completed');
    }
    
  } else {
    // Task failed
    console.log('Task failed:', msg);
  }
  
  // Return 200 status code to confirm callback received
  res.status(200).json({ status: 'received' });
});

app.listen(3000, () => {
  console.log('Vocals callback server running on port 3000');
});

Best Practices

Callback URL Configuration Recommendations

1. Use HTTPS: Ensure your callback URL uses HTTPS protocol for secure data transmission
2. Verify Source: Verify the legitimacy of the request source in callback processing
3. Idempotent Processing: The same task_id may receive multiple callbacks, ensure processing logic is idempotent
4. Quick Response: Callback processing should return a 200 status code as quickly as possible to avoid timeout
5. Asynchronous Processing: Complex business logic should be processed asynchronously to avoid blocking callback response
6. Stage Tracking: Differentiate between different generation stages based on callbackType and arrange business logic appropriately

Important Reminders

• Callback URL must be a publicly accessible address
• Server must respond within 15 seconds, otherwise it will be considered a timeout
• If 3 consecutive retries fail, the system will stop sending callbacks
• Please ensure the stability of callback processing logic to avoid callback failures due to exceptions
• Pay attention to handling different callbackType callbacks, especially the complete type for final results

Alternative Solution

If you cannot use the callback mechanism, you can also use polling:

Poll Query Results

Use the get music details endpoint to regularly query task status. We recommend querying every 30 seconds.