Lyrics Generation Callbacks

System will call this callback when lyrics generation is complete.

When you submit a lyrics generation 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

INFO

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:

• Lyrics generation task completed successfully
• Lyrics 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 is completed, the system will send a POST request to your callBackUrl in the following format:

Success Callback

{
  "code": 200,
  "msg": "All generated successfully.",
  "data": {
    "callbackType": "complete",
    "task_id": "3b66882fde0a5d398bd269cab6d9542b",
    "data": [
      {
        "error_message": "",
        "status": "complete",
        "text": "[Verse]\nMoonlight spreads across the windowsill\nStars dance, never standing still\nNight breeze weaves dreams with gentle skill\nLeaving all worries on the hill\n\n[Verse 2]\nLights reflect in your bright eyes\nLike meteors across the skies\nThe world stops in that moment's prize\nChasing future, no goodbyes\n\n[Chorus]\nIn starry dreams we find tomorrow\nBreak free from ordinary sorrow\nAll our dreams will bloom and follow\nDon't fear the path, don't fear tomorrow",
        "title": "Starry Night Dreams"
      }
    ]
  }
}

Failure Callback

{
  "code": 400,
  "msg": "Song Description flagged for moderation",
  "data": {
    "callbackType": "complete",
    "task_id": "3b66882fde0a5d398bd269cab6d9542b",
    "data": null
  }
}

Status Code Description

code (integer, required)

Callback status code indicating task processing result:

Status Code	Description
200	Success - Request has been processed successfully
400	Please try rephrasing with more specific details or using a different approach
500	Internal Error - Please try again later

msg (string, required)

Status message providing detailed status description

data.callbackType (string, required)

Callback type, fixed as complete

data.task_id (string, required)

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

data.data (array, required)

Generated lyrics list

data.data[].text (string)

Lyrics content, returns complete lyrics text on success

data.data[].title (string)

Lyrics title

data.data[].status (string, required)

Generation status:

• complete - Generation successful
• failed - Generation failed

data.data[].error_message (string)

Error message, valid when status is failed

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('/suno-lyrics-callback', (req, res) => {
  const { code, msg, data } = req.body;
  
  console.log('Received lyrics callback:', {
    taskId: data.task_id,
    status: code,
    message: msg,
    callbackType: data.callbackType
  });
  
  if (code === 200) {
    // Task completed successfully
    console.log('Lyrics generation completed:', data.data);
    
    // Process generated lyrics data
    data.data.forEach(lyrics => {
      if (lyrics.status === 'complete') {
        console.log(`Lyrics title: ${lyrics.title}`);
        console.log(`Lyrics content: ${lyrics.text}`);
      } else if (lyrics.status === 'failed') {
        console.log(`Lyrics generation failed: ${lyrics.error_message}`);
      }
    });
    
  } else {
    // Task failed
    console.log('Task 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');
});

Python

from flask import Flask, request, jsonify
import json

app = Flask(__name__)

@app.route('/suno-lyrics-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')
    callback_type = callback_data.get('callbackType')
    
    print(f"Received lyrics callback: {task_id}, status: {code}, type: {callback_type}, message: {msg}")
    
    if code == 200:
        # Task completed successfully
        lyrics_list = callback_data.get('data', [])
        print(f"Lyrics generation completed, generated {len(lyrics_list)} lyrics")
        
        for lyrics in lyrics_list:
            if lyrics['status'] == 'complete':
                print(f"Lyrics title: {lyrics['title']}")
                print(f"Lyrics content: {lyrics['text']}")
            elif lyrics['status'] == 'failed':
                print(f"Lyrics generation failed: {lyrics['error_message']}")
                
    else:
        # Task failed
        print(f"Task failed: {msg}")
        
        # Handle failure cases...
    
    # 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

<?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'] ?? '';
$callbackType = $callbackData['callbackType'] ?? '';

error_log("Received lyrics callback: $taskId, status: $code, type: $callbackType, message: $msg");

if ($code === 200) {
    // Task completed successfully
    $lyricsList = $callbackData['data'] ?? [];
    error_log("Lyrics generation completed, generated " . count($lyricsList) . " lyrics");
    
    foreach ($lyricsList as $lyrics) {
        if ($lyrics['status'] === 'complete') {
            error_log("Lyrics title: " . $lyrics['title']);
            error_log("Lyrics content: " . $lyrics['text']);
        } elseif ($lyrics['status'] === 'failed') {
            error_log("Lyrics generation failed: " . $lyrics['error_message']);
        }
    }
    
} else {
    // Task failed
    error_log("Task failed: $msg");
    
    // Handle failure cases...
}

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

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. Status Checking: Check the status field of each lyrics item to distinguish between success and failure cases

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 lyrics generation failure cases, check the error_message field for specific error information

Troubleshooting

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

Network Connection Issues

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

Server Response Issues

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

Content Format Issues

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

Lyrics Processing Issues

• Confirm proper handling of lyrics status field
• Check if processing of failed status lyrics is missed
• Verify that lyrics content parsing is correct

Alternative Solution

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

Poll Query Results

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