Audio Separation Callbacks

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.

Webhook Security: To ensure the authenticity and integrity of callback requests, we strongly recommend implementing webhook signature verification. See our Webhook Verification Guide for detailed implementation steps.

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

Callback Request Format

When the task is completed, the system will send a POST request to your callBackUrl based on the separation type you selected. Different separation types correspond to different callback data structures:

separate_vocal Type Callbacks

{
  "code": 200,
  "msg": "vocal separation generated successfully.",
  "data": {
    "task_id": "3e63b4cc88d52611159371f6af5571e7",
    "vocal_separation_info": {
      "instrumental_url": "https://file.aiquickdraw.com/s/d92a13bf-c6f4-4ade-bb47-f69738435528_Instrumental.mp3",
      "origin_url": "",
      "vocal_url": "https://file.aiquickdraw.com/s/3d7021c9-fa8b-4eda-91d1-3b9297ddb172_Vocals.mp3"
    }
  }
}

{
  "code": 500,
  "msg": "Vocal separation failed",
  "data": {
    "task_id": "3e63b4cc88d52611159371f6af5571e7",
    "vocal_separation_info": null
  }
}

split_stem Type Callbacks

{
  "code": 200,
  "msg": "vocal separation generated successfully.",
  "data": {
    "task_id": "e649edb7abfd759285bd41a47a634b10",
    "vocal_separation_info": {
      "origin_url": "",
      "backing_vocals_url": "https://file.aiquickdraw.com/s/aadc51a3-4c88-4c8e-a4c8-e867c539673d_Backing_Vocals.mp3",
      "bass_url": "https://file.aiquickdraw.com/s/a3c2da5a-b364-4422-adb5-2692b9c26d33_Bass.mp3",
      "brass_url": "https://file.aiquickdraw.com/s/334b2d23-0c65-4a04-92c7-22f828afdd44_Brass.mp3",
      "drums_url": "https://file.aiquickdraw.com/s/ac75c5ea-ac77-4ad2-b7d9-66e140b78e44_Drums.mp3",
      "fx_url": "https://file.aiquickdraw.com/s/a8822c73-6629-4089-8f2a-d19f41f0007d_FX.mp3",
      "guitar_url": "https://file.aiquickdraw.com/s/064dd08e-d5d2-4201-9058-c5c40fb695b4_Guitar.mp3",
      "keyboard_url": "https://file.aiquickdraw.com/s/adc934e0-df7d-45da-8220-1dba160d74e0_Keyboard.mp3",
      "percussion_url": "https://file.aiquickdraw.com/s/0f70884d-047c-41f1-a6d0-7044618b7dc6_Percussion.mp3",
      "strings_url": "https://file.aiquickdraw.com/s/49829425-a5b0-424e-857a-75d4c63a426b_Strings.mp3",
      "synth_url": "https://file.aiquickdraw.com/s/56b2d94a-eb92-4d21-bc43-3460de0c8348_Synth.mp3",
      "vocal_url": "https://file.aiquickdraw.com/s/07420749-29a2-4054-9b62-e6a6f8b90ccb_Vocals.mp3",
      "woodwinds_url": "https://file.aiquickdraw.com/s/d81545b1-6f94-4388-9785-1aaa6ecabb02_Woodwinds.mp3"
    }
  }
}

{
  "code": 500,
  "msg": "Instrument separation failed",
  "data": {
    "task_id": "e649edb7abfd759285bd41a47a634b10",
    "vocal_separation_info": null
  }
}

Status Code Description

integer

required

Callback status code indicating task processing result:

Status Code	Description
200	Success - Request has been processed successfully
500	Internal Error - Please try again later

string

required

Status message providing detailed status description

string

required

Task ID, consistent with the task_id returned when you submitted the task

object

Vocal separation result information, returned on success. The returned fields depend on the separation type (type parameter)

separate_vocal Type Callback Fields

string

Instrumental part audio URL (separate_vocal type only)

string

Original audio URL

string

Vocal part audio URL

split_stem Type Callback Fields

string

Original audio URL

string

Main vocal audio URL

string

Backing vocals audio URL (split_stem type only)

string

Drums part audio URL (split_stem type only)

string

Bass part audio URL (split_stem type only)

string

Guitar part audio URL (split_stem type only)

string

Keyboard part audio URL (split_stem type only)

string

Percussion part audio URL (split_stem type only)

string

Strings part audio URL (split_stem type only)

string

Synthesizer part audio URL (split_stem type only)

string

Effects part audio URL (split_stem type only)

string

Brass part audio URL (split_stem type only)

string

Woodwinds part audio URL (split_stem type only)

Callback Reception Examples

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

Node.js
Python
PHP

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(`Vocal part: ${vocalInfo.vocal_url}`);
      
      // separate_vocal type specific fields
      if (vocalInfo.instrumental_url) {
        console.log(`Instrumental part: ${vocalInfo.instrumental_url}`);
      }
      
      // split_stem type specific fields
      if (vocalInfo.backing_vocals_url) {
        console.log(`Backing vocals: ${vocalInfo.backing_vocals_url}`);
        console.log(`Drums part: ${vocalInfo.drums_url}`);
        console.log(`Bass part: ${vocalInfo.bass_url}`);
        console.log(`Guitar part: ${vocalInfo.guitar_url}`);
        console.log(`Keyboard part: ${vocalInfo.keyboard_url}`);
        console.log(`Percussion part: ${vocalInfo.percussion_url}`);
        console.log(`Strings part: ${vocalInfo.strings_url}`);
        console.log(`Synthesizer part: ${vocalInfo.synth_url}`);
        console.log(`Effects part: ${vocalInfo.fx_url}`);
        console.log(`Brass part: ${vocalInfo.brass_url}`);
        console.log(`Woodwinds part: ${vocalInfo.woodwinds_url}`);
      }
      
      // Process separated audio files
      // Can download files, save locally, etc.
    }
    
  } else {
    // Task failed
    console.log('Vocal separation failed:', msg);
    
    // Handle failure scenarios...
  }
  
  // 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');
});

from flask import Flask, request, jsonify
import requests
import os

app = Flask(__name__)

@app.route('/suno-vocal-separation-callback', methods=['POST'])
def handle_callback():
    data = request.json
    
    code = data.get('code')
    msg = data.get('msg')
    callback_data = data.get('data', {})
    task_id = callback_data.get('task_id')
    vocal_info = callback_data.get('vocal_separation_info')
    
    print(f"Received vocal separation callback: {task_id}, status: {code}, message: {msg}")
    
    if code == 200:
        # Task completed successfully
        print("Vocal separation completed")
        
        if vocal_info:
            print("Separation results:")
            print(f"Original audio: {vocal_info.get('origin_url')}")
            print(f"Vocal part: {vocal_info.get('vocal_url')}")
            
            # separate_vocal type specific fields
            if vocal_info.get('instrumental_url'):
                print(f"Instrumental part: {vocal_info.get('instrumental_url')}")
            
            # split_stem type specific fields
            if vocal_info.get('backing_vocals_url'):
                print(f"Backing vocals: {vocal_info.get('backing_vocals_url')}")
                print(f"Drums part: {vocal_info.get('drums_url')}")
                print(f"Bass part: {vocal_info.get('bass_url')}")
                print(f"Guitar part: {vocal_info.get('guitar_url')}")
                print(f"Keyboard part: {vocal_info.get('keyboard_url')}")
                print(f"Percussion part: {vocal_info.get('percussion_url')}")
                print(f"Strings part: {vocal_info.get('strings_url')}")
                print(f"Synthesizer part: {vocal_info.get('synth_url')}")
                print(f"Effects part: {vocal_info.get('fx_url')}")
                print(f"Brass part: {vocal_info.get('brass_url')}")
                print(f"Woodwinds part: {vocal_info.get('woodwinds_url')}")
            
            # Process separated audio files
            # Download file example
            def download_audio_file(url, filename):
                if url:
                    try:
                        response = requests.get(url)
                        if response.status_code == 200:
                            with open(filename, "wb") as f:
                                f.write(response.content)
                            print(f"Saved: {filename}")
                    except Exception as e:
                        print(f"Download failed {filename}: {e}")
            
            # Create directory
            os.makedirs(f"vocal_separation_{task_id}", exist_ok=True)
            
            # Download separated audio files
            download_audio_file(vocal_info.get('vocal_url'), 
                              f"vocal_separation_{task_id}/vocal.mp3")
            
            # separate_vocal type files
            if vocal_info.get('instrumental_url'):
                download_audio_file(vocal_info.get('instrumental_url'), 
                                  f"vocal_separation_{task_id}/instrumental.mp3")
            
            # split_stem type files
            if vocal_info.get('backing_vocals_url'):
                stem_files = {
                    'backing_vocals': vocal_info.get('backing_vocals_url'),
                    'drums': vocal_info.get('drums_url'),
                    'bass': vocal_info.get('bass_url'),
                    'guitar': vocal_info.get('guitar_url'),
                    'keyboard': vocal_info.get('keyboard_url'),
                    'percussion': vocal_info.get('percussion_url'),
                    'strings': vocal_info.get('strings_url'),
                    'synth': vocal_info.get('synth_url'),
                    'fx': vocal_info.get('fx_url'),
                    'brass': vocal_info.get('brass_url'),
                    'woodwinds': vocal_info.get('woodwinds_url')
                }
                
                for name, url in stem_files.items():
                    download_audio_file(url, f"vocal_separation_{task_id}/{name}.mp3")
                
    else:
        # Task failed
        print(f"Vocal separation failed: {msg}")
        
        # Handle failure scenarios...
    
    # Return 200 status code to confirm callback received
    return jsonify({'status': 'received'}), 200

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=3000)

<?php
header('Content-Type: application/json');

// Get POST data
$input = file_get_contents('php://input');
$data = json_decode($input, true);

$code = $data['code'] ?? null;
$msg = $data['msg'] ?? '';
$callbackData = $data['data'] ?? [];
$taskId = $callbackData['task_id'] ?? '';
$vocalInfo = $callbackData['vocal_separation_info'] ?? null;

error_log("Received vocal separation callback: $taskId, status: $code, message: $msg");

if ($code === 200) {
    // Task completed successfully
    error_log("Vocal separation completed");
    
    if ($vocalInfo) {
        error_log("Separation results:");
        error_log("Original audio: " . ($vocalInfo['origin_url'] ?? ''));
        error_log("Vocal part: " . ($vocalInfo['vocal_url'] ?? ''));
        
        // separate_vocal type specific fields
        if (!empty($vocalInfo['instrumental_url'])) {
            error_log("Instrumental part: " . $vocalInfo['instrumental_url']);
        }
        
        // split_stem type specific fields
        if (!empty($vocalInfo['backing_vocals_url'])) {
            error_log("Backing vocals: " . $vocalInfo['backing_vocals_url']);
            error_log("Drums part: " . ($vocalInfo['drums_url'] ?? ''));
            error_log("Bass part: " . ($vocalInfo['bass_url'] ?? ''));
            error_log("Guitar part: " . ($vocalInfo['guitar_url'] ?? ''));
            error_log("Keyboard part: " . ($vocalInfo['keyboard_url'] ?? ''));
            error_log("Percussion part: " . ($vocalInfo['percussion_url'] ?? ''));
            error_log("Strings part: " . ($vocalInfo['strings_url'] ?? ''));
            error_log("Synthesizer part: " . ($vocalInfo['synth_url'] ?? ''));
            error_log("Effects part: " . ($vocalInfo['fx_url'] ?? ''));
            error_log("Brass part: " . ($vocalInfo['brass_url'] ?? ''));
            error_log("Woodwinds part: " . ($vocalInfo['woodwinds_url'] ?? ''));
        }
        
        // Process separated audio files
        function downloadAudioFile($url, $filename) {
            if (!empty($url)) {
                try {
                    $audioContent = file_get_contents($url);
                    if ($audioContent !== false) {
                        file_put_contents($filename, $audioContent);
                        error_log("Saved: $filename");
                    }
                } catch (Exception $e) {
                    error_log("Download failed $filename: " . $e->getMessage());
                }
            }
        }
        
        // Create directory
        $dir = "vocal_separation_$taskId";
        if (!is_dir($dir)) {
            mkdir($dir, 0777, true);
        }
        
        // Download basic files
        downloadAudioFile($vocalInfo['vocal_url'] ?? '', "$dir/vocal.mp3");
        
        // separate_vocal type files
        if (!empty($vocalInfo['instrumental_url'])) {
            downloadAudioFile($vocalInfo['instrumental_url'], "$dir/instrumental.mp3");
        }
        
        // split_stem type files
        if (!empty($vocalInfo['backing_vocals_url'])) {
            $stemFiles = [
                'backing_vocals' => $vocalInfo['backing_vocals_url'] ?? '',
                'drums' => $vocalInfo['drums_url'] ?? '',
                'bass' => $vocalInfo['bass_url'] ?? '',
                'guitar' => $vocalInfo['guitar_url'] ?? '',
                'keyboard' => $vocalInfo['keyboard_url'] ?? '',
                'percussion' => $vocalInfo['percussion_url'] ?? '',
                'strings' => $vocalInfo['strings_url'] ?? '',
                'synth' => $vocalInfo['synth_url'] ?? '',
                'fx' => $vocalInfo['fx_url'] ?? '',
                'brass' => $vocalInfo['brass_url'] ?? '',
                'woodwinds' => $vocalInfo['woodwinds_url'] ?? ''
            ];
            
            foreach ($stemFiles as $name => $url) {
                downloadAudioFile($url, "$dir/$name.mp3");
            }
        }
    }
    
} else {
    // Task failed
    error_log("Vocal separation failed: $msg");
    
    // Handle failure scenarios...
}

// Return 200 status code to confirm callback received
http_response_code(200);
echo json_encode(['status' => 'received']);
?>

Best Practices

Callback URL Configuration Recommendations

Use HTTPS: Ensure callback URL uses HTTPS protocol for secure data transmission
Verify Origin: Verify the legitimacy of the request source in callback processing
Idempotent Processing: The same task_id may receive multiple callbacks, ensure processing logic is idempotent
Quick Response: Callback processing should return 200 status code quickly to avoid timeout
Asynchronous Processing: Complex business logic should be processed asynchronously to avoid blocking callback responses
Type-based Processing: Handle different audio file structures based on different separation types
Batch Download: split_stem type produces multiple files, recommend batch downloading and organizing by type

Important Reminders

Callback URL must be publicly accessible
Server must respond within 15 seconds, otherwise will be considered timeout
If 3 consecutive retry attempts fail, the system will stop sending callbacks
Please ensure the stability of callback processing logic to avoid callback failures due to exceptions
Vocal separation generated audio file URLs may have time limits, recommend downloading and saving promptly
Note that some audio part URLs may be empty, certain instrument separations might be empty
separate_vocal and split_stem types return different fields, please handle corresponding fields based on the type parameter in the request

Troubleshooting

If you are not receiving callback notifications, please check the following:

Network Connection Issues

Confirm callback URL is accessible from public internet
Check firewall settings to ensure inbound requests are not blocked
Verify domain name resolution is correct

Server Response Issues

Ensure server returns HTTP 200 status code within 15 seconds
Check server logs for error messages
Verify endpoint path and HTTP method are correct

Content Format Issues

Confirm received POST request body is in JSON format
Check if Content-Type is application/json
Verify JSON parsing is correct

File Processing Issues

Confirm all audio file URLs are accessible
Check file download permissions and network connection
Verify file save path and permissions
Note that some instrument separation results may be empty
Note the field differences between separate_vocal and split_stem types

Alternative Solutions

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

Poll Query Results

Use the Get Vocal Separation Details endpoint to periodically query task status. We recommend querying every 30 seconds.

Image Models

Video Models

Music Models

Chat Models

Veo3.1 API

Suno API

Audio Separation Callbacks

Callback Mechanism Overview

Callback Timing

Callback Method

Callback Request Format

separate_vocal Type Callbacks

split_stem Type Callbacks

Status Code Description

separate_vocal Type Callback Fields

split_stem Type Callback Fields

Callback Reception Examples

Best Practices

Callback URL Configuration Recommendations

Important Reminders

Troubleshooting

Alternative Solutions

Poll Query Results

​Callback Mechanism Overview

​Callback Timing

​Callback Method

​Callback Request Format

​separate_vocal Type Callbacks

​split_stem Type Callbacks

​Status Code Description

​separate_vocal Type Callback Fields

​split_stem Type Callback Fields

​Callback Reception Examples

​Best Practices

​Callback URL Configuration Recommendations

​Important Reminders

​Troubleshooting

​Alternative Solutions

Poll Query Results

Callback Mechanism Overview

Callback Timing

Callback Method

Callback Request Format

separate_vocal Type Callbacks

split_stem Type Callbacks

Status Code Description

separate_vocal Type Callback Fields

split_stem Type Callback Fields

Callback Reception Examples

Best Practices

Callback URL Configuration Recommendations

Important Reminders

Troubleshooting

Alternative Solutions