WAV Format Conversion Callbacks

When you submit a task to the WAV Format Conversion API, you can use the callBackUrl parameter to set a callback URL. When the task is completed, the system will automatically push the results to your specified address.

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:

WAV format conversion task completed successfully
WAV format conversion 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:

{
  "code": 200,
  "msg": "success",
  "data": {
    "audioWavUrl": "https://example.com/s/04e6****e727.wav",
    "task_id": "988e****c8d3"
  }
}

Status Code Description

code

integer

required

Callback status code indicating task processing result:

Status Code	Description
200	Success - WAV format conversion completed
400	Bad Request - Parameter error, unsupported source audio file format, etc.
451	Download Failed - Unable to download source audio file
500	Server Error - Please try again later

msg

string

required

Status message providing detailed status description

data.task_id

string

required

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

data.audioWavUrl

string

Converted WAV audio file download URL, returned on success

Callback Reception Examples

Here 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('/wav-conversion-callback', (req, res) => {
  const { code, msg, data } = req.body;
  
  console.log('Received WAV format conversion callback:', {
    taskId: data.task_id,
    status: code,
    message: msg
  });
  
  if (code === 200) {
    // Task completed successfully
    console.log('WAV format conversion completed');
    console.log(`WAV file URL: ${data.audioWavUrl}`);
    
    // Download WAV file
    if (data.audioWavUrl) {
      const https = require('https');
      const fs = require('fs');
      
      const filename = `wav_${data.task_id}.wav`;
      const file = fs.createWriteStream(filename);
      
      https.get(data.audioWavUrl, (response) => {
        response.pipe(file);
        file.on('finish', () => {
          file.close();
          console.log(`WAV file saved as ${filename}`);
        });
      }).on('error', (err) => {
        console.error('WAV file download failed:', err.message);
      });
    }
    
  } else {
    // Task failed
    console.log('WAV format conversion failed:', msg);
    
    // Handle failure cases...
    if (code === 400) {
      console.log('Parameter error or unsupported source file format');
    } else if (code === 451) {
      console.log('Source audio file download failed');
    } else if (code === 500) {
      console.log('Server internal error');
    }
  }
  
  // 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

app = Flask(__name__)

@app.route('/wav-conversion-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')
    audioWavUrl = callback_data.get('audioWavUrl')
    
    print(f"Received WAV format conversion callback: {task_id}, status: {code}, message: {msg}")
    
    if code == 200:
        # Task completed successfully
        print("WAV format conversion completed")
        print(f"WAV file URL: {audioWavUrl}")
        
        # Download WAV file example
        if audioWavUrl:
            try:
                response = requests.get(audioWavUrl)
                if response.status_code == 200:
                    filename = f"wav_{task_id}.wav"
                    with open(filename, "wb") as f:
                        f.write(response.content)
                    print(f"WAV file saved as {filename}")
            except Exception as e:
                print(f"WAV file download failed: {e}")
                
    else:
        # Task failed
        print(f"WAV format conversion failed: {msg}")
        
        # Handle failure cases...
        if code == 400:
            print("Parameter error or unsupported source file format")
        elif code == 451:
            print("Source audio file download failed")
        elif code == 500:
            print("Server internal error")
    
    # 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'] ?? '';
$audioWavUrl = $callbackData['audioWavUrl'] ?? '';

error_log("Received WAV format conversion callback: $taskId, status: $code, message: $msg");

if ($code === 200) {
    // Task completed successfully
    error_log("WAV format conversion completed");
    error_log("WAV file URL: $audioWavUrl");
    
    // Download WAV file example
    if ($audioWavUrl) {
        try {
            $wavContent = file_get_contents($audioWavUrl);
            if ($wavContent !== false) {
                $filename = "wav_{$taskId}.wav";
                file_put_contents($filename, $wavContent);
                error_log("WAV file saved as $filename");
            }
        } catch (Exception $e) {
            error_log("WAV file download failed: " . $e->getMessage());
        }
    }
    
} else {
    // Task failed
    error_log("WAV format conversion failed: $msg");
    
    // Handle failure cases...
    if ($code === 400) {
        error_log("Parameter error or unsupported source file format");
    } elseif ($code === 451) {
        error_log("Source audio file download failed");
    } elseif ($code === 500) {
        error_log("Server internal error");
    }
}

// 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 your callback URL uses HTTPS protocol for secure data transmission
Verify Source: Verify the legitimacy of the request source in callback processing
Idempotent Processing: The same taskId may receive multiple callbacks, ensure processing logic is idempotent
Quick Response: Callback processing should return a 200 status code as quickly as possible to avoid timeout
Asynchronous Processing: Complex business logic should be processed asynchronously to avoid blocking callback response
File Processing: WAV file download and processing should be done in asynchronous tasks to avoid blocking callback response

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
Generated WAV file URLs may have time limits, recommend downloading and saving promptly
WAV files are typically larger than MP3 files, pay attention to storage space and download time
Ensure sufficient disk space to save WAV files

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

File Processing Issues

Confirm that WAV file URLs are accessible
Check file download permissions and network connections
Verify file save paths and permissions
Note WAV file size, ensure sufficient storage space
Confirm source audio file format is supported

Alternative Solution

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

Poll Query Results

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

Generate Music

Generate Lyrics

WAV Conversion

Vocal Removal

Music Video Generation

Account Management

File Upload API

WAV Format Conversion Callbacks

Callback Mechanism Overview

Callback Timing

Callback Method

Callback Request Format

Status Code Description

Callback Reception Examples

Best Practices

Callback URL Configuration Recommendations

Important Reminders

Troubleshooting

Alternative Solution

Poll Query Results

Generate Music

Generate Lyrics

WAV Conversion

Vocal Removal

Music Video Generation

Account Management

File Upload API

​Callback Mechanism Overview

​Callback Timing

​Callback Method

​Callback Request Format

​Status Code Description

​Callback Reception Examples

​Best Practices

​Callback URL Configuration Recommendations

​Important Reminders

​Troubleshooting

​Alternative Solution

Poll Query Results

Callback Mechanism Overview

Callback Timing

Callback Method

Callback Request Format

Status Code Description

Callback Reception Examples

Best Practices

Callback URL Configuration Recommendations

Important Reminders

Troubleshooting

Alternative Solution