When you submit a vocal separation task to the Suno API, 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.

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:
  • Vocal separation task completed successfully
  • Vocal separation task failed
  • Errors occurred during task processing

Callback Method

  • HTTP Method: POST
  • Content Type: application/json
  • Timeout Setting: 15 seconds
  • Retry Mechanism: Retry 3 times after failure, with intervals of 1 minute, 5 minutes, and 15 minutes respectively

Callback Request Format

When the task is completed, the system will send a POST request to your callBackUrl in the following format:
{
  "code": 200,
  "msg": "vocal separation generated successfully.",
  "data": {
    "task_id": "5e72d367bdfbe44785e28d72cb1697c7",
    "vocal_separation_info": {
      "instrumental_url": "https://tempfile.aiquickdraw.com/v/94322944-2c96-4be3-b7fb-606e3924a8d2_instrumental.mp3",
      "origin_url": "https://cdn1.suno.ai/549fc4b2-294f-44ea-a35b-419687b07ab9.mp3",
      "vocal_url": "https://tempfile.aiquickdraw.com/v/94322944-2c96-4be3-b7fb-606e3924a8d2_vocal.mp3",
      "drums_url": "https://tempfile.aiquickdraw.com/v/94322944-2c96-4be3-b7fb-606e3924a8d2_drums.mp3",
      "bass_url": "https://tempfile.aiquickdraw.com/v/94322944-2c96-4be3-b7fb-606e3924a8d2_bass.mp3",
      "guitar_url": "https://tempfile.aiquickdraw.com/v/94322944-2c96-4be3-b7fb-606e3924a8d2_guitar.mp3",
      "piano_url": "https://tempfile.aiquickdraw.com/v/94322944-2c96-4be3-b7fb-606e3924a8d2_piano.mp3"
    }
  }
}

Status Code Description

code
integer
required
Callback status code indicating task processing result:
Status CodeDescription
200Success - Request has been processed successfully
500Internal Error - Please try again later
msg
string
required
Status message providing detailed status description
data.task_id
string
required
Task ID, consistent with the task_id returned when you submitted the task
data.vocal_separation_info
object
Vocal separation result information, returned on success
data.vocal_separation_info.instrumental_url
string
Instrumental part audio URL
data.vocal_separation_info.origin_url
string
Original audio URL
data.vocal_separation_info.vocal_url
string
Vocal part audio URL
data.vocal_separation_info.drums_url
string
Drums part audio URL
data.vocal_separation_info.bass_url
string
Bass part audio URL
data.vocal_separation_info.guitar_url
string
Guitar part audio URL
data.vocal_separation_info.piano_url
string
Piano part audio URL

Callback Reception Examples

Here are example codes for receiving callbacks in popular programming languages:
const express = require('express');
const app = express();

app.use(express.json());

app.post('/suno-vocal-separation-callback', (req, res) => {
  const { code, msg, data } = req.body;
  
  console.log('Received vocal separation callback:', {
    taskId: data.task_id,
    status: code,
    message: msg
  });
  
  if (code === 200) {
    // Task completed successfully
    console.log('Vocal separation completed');
    const vocalInfo = data.vocal_separation_info;
    
    if (vocalInfo) {
      console.log('Separation results:');
      console.log(`Original audio: ${vocalInfo.origin_url}`);
      console.log(`Instrumental part: ${vocalInfo.instrumental_url}`);
      console.log(`Vocal part: ${vocalInfo.vocal_url}`);
      console.log(`Drums part: ${vocalInfo.drums_url}`);
      console.log(`Bass part: ${vocalInfo.bass_url}`);
      console.log(`Guitar part: ${vocalInfo.guitar_url}`);
      console.log(`Piano part: ${vocalInfo.piano_url}`);
      
      // Process separated audio files
      // Can download files, save locally, etc.
    }
    
  } else {
    // Task failed
    console.log('Vocal separation failed:', msg);
    
    // Handle failure cases...
  }
  
  // Return 200 status code to confirm callback received
  res.status(200).json({ status: 'received' });
});

app.listen(3000, () => {
  console.log('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. Batch Download: Vocal separation produces multiple files, recommend batch downloading and organizing by type

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
  • Audio file URLs generated by vocal separation may have time limits, recommend downloading and saving promptly
  • Note that some audio part URLs may be unavailable, certain instrument separations may be empty

Troubleshooting

If you do not receive callback notifications, please check the following:

Alternative Solution

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

Poll Query Results

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