Audio Separation Callbacks

System will call this callback when vocal and instrument separation is complete.

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

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

Success Callback - separate_vocal

{
  "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"
    }
  }
}

split_stem Type Callbacks

Success Callback - split_stem

{
  "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"
    }
  }
}

Status Code Description

code · 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

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. The returned fields depend on the separation type (type parameter)

separate_vocal Type Callback Fields

data.vocal_separation_info.instrumental_url · string

Instrumental part audio URL (separate_vocal type only)

data.vocal_separation_info.origin_url · string

Original audio URL

data.vocal_separation_info.vocal_url · string

Vocal part audio URL

split_stem Type Callback Fields

data.vocal_separation_info.origin_url · string

Original audio URL

data.vocal_separation_info.vocal_url · string

Main vocal audio URL

data.vocal_separation_info.backing_vocals_url · string

Backing vocals audio URL (split_stem type only)

data.vocal_separation_info.drums_url · string

Drums part audio URL (split_stem type only)

data.vocal_separation_info.bass_url · string

Bass part audio URL (split_stem type only)

data.vocal_separation_info.guitar_url · string

Guitar part audio URL (split_stem type only)

data.vocal_separation_info.keyboard_url · string

Keyboard part audio URL (split_stem type only)

data.vocal_separation_info.percussion_url · string

Percussion part audio URL (split_stem type only)

data.vocal_separation_info.strings_url · string

Strings part audio URL (split_stem type only)

data.vocal_separation_info.synth_url · string

Synthesizer part audio URL (split_stem type only)

data.vocal_separation_info.fx_url · string

Effects part audio URL (split_stem type only)

data.vocal_separation_info.brass_url · string

Brass part audio URL (split_stem type only)

data.vocal_separation_info.woodwinds_url · 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

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');
});

Best Practices

Callback URL Configuration Recommendations

1. Use HTTPS: Ensure callback URL uses HTTPS protocol for secure data transmission
2. Verify Origin: 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 200 status code quickly to avoid timeout
5. Asynchronous Processing: Complex business logic should be processed asynchronously to avoid blocking callback responses
6. Type-based Processing: Handle different audio file structures based on different separation types
7. 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.