When you submit a WAV format conversion 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:
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
When the task is completed, the system will send a POST request to your callBackUrl in the following format:
Success Callback
Failure Callback
{
"code" : 200 ,
"msg" : "success" ,
"data" : {
"audioWavUrl" : "https://example.com/s/04e6****e727.wav" ,
"task_id" : "988e****c8d3"
}
}
Status Code Description
Callback status code indicating task processing result: Status Code Description 200 Success - Request has been processed successfully 500 Internal Error - Please try again later
Status message providing detailed status description
Task ID, consistent with the task_id returned when you submitted the task
WAV format audio file URL, returned on success with accessible download link
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-wav-callback' , ( req , res ) => {
const { code , msg , data } = req . body ;
console . log ( 'Received WAV conversion callback:' , {
taskId: data . task_id ,
status: code ,
message: msg
});
if ( code === 200 ) {
// Task completed successfully
console . log ( 'WAV conversion completed' );
console . log ( `WAV file URL: ${ data . audioWavUrl } ` );
// Process generated WAV file
// Can download file, save locally, etc.
} else {
// Task failed
console . log ( 'WAV conversion 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' );
});
from flask import Flask, request, jsonify
import requests
app = Flask( __name__ )
@app.route ( '/suno-wav-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' )
audio_wav_url = callback_data.get( 'audioWavUrl' )
print ( f "Received WAV conversion callback: { task_id } , status: { code } , message: { msg } " )
if code == 200 :
# Task completed successfully
print ( "WAV conversion completed" )
print ( f "WAV file URL: { audio_wav_url } " )
# Process generated WAV file
# Can download file, save locally, etc.
if audio_wav_url:
try :
# Download WAV file example
response = requests.get(audio_wav_url)
if response.status_code == 200 :
with open ( f "wav_file_ { task_id } .wav" , "wb" ) as f:
f.write(response.content)
print ( f "WAV file saved as wav_file_ { task_id } .wav" )
except Exception as e:
print ( f "WAV file download failed: { e } " )
else :
# Task failed
print ( f "WAV conversion 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
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 conversion callback: $taskId , status: $code , message: $msg " );
if ( $code === 200 ) {
// Task completed successfully
error_log ( "WAV conversion completed" );
error_log ( "WAV file URL: $audioWavUrl " );
// Process generated WAV file
if ( ! empty ( $audioWavUrl )) {
try {
// Download WAV file example
$wavContent = file_get_contents ( $audioWavUrl );
if ( $wavContent !== false ) {
$filename = "wav_file_{ $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 conversion 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
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 task_id 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
WAV file URLs may have time limits, recommend downloading and saving promptly
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
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
Confirm that the received POST request body is in JSON format
Check that Content-Type is application/json
Verify that JSON parsing is correct
Confirm that the WAV file URL is accessible
Check file download permissions and network connections
Verify file save paths and permissions
Alternative Solution
If you cannot use the callback mechanism, you can also use polling:
Poll Query Results Use the get WAV details endpoint to regularly query task status. We recommend querying every 30 seconds.