4o Image Generation Callbacks

When the 4o Image task is completed, the system will send the result to your provided callback URL via POST request

When you submit an image generation task to the 4o Image 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:

• 4o image generation task completed successfully
• 4o image 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": "success",
  "data": {
    "taskId": "task12345",
    "info": {
      "result_urls": [
        "https://example.com/result/image1.png"
      ]
    }
  }
}

Status Code Description

code · integer · required

Callback status code indicating task processing result:

Status Code	Description
200	Success - Image generation completed successfully
400	Bad Request - Image content in filesUrl violates content policy, image size exceeds maximum limit, unable to process provided image file, content flagged by OpenAI as violating policies
451	Download Failed - Unable to download image from the provided filesUrl
500	Server Error - Please try again later, failed to get user token, failed to generate image, GPT 4O failed to edit the picture

msg · string · required

Status message providing detailed status description

data.taskId · string · required

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

data.info · object

Image generation result information, returned on success

data.info.result_urls · array

List of generated image URLs, returned on success with accessible download links

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('/4o-image-callback', (req, res) => {
  const { code, msg, data } = req.body;
  
  console.log('Received 4o image generation callback:', {
    taskId: data.taskId,
    status: code,
    message: msg
  });
  
  if (code === 200) {
    // Task completed successfully
    console.log('4o image generation completed');
    const resultUrls = data.info?.result_urls || [];
    
    console.log(`Generated ${resultUrls.length} images:`);
    resultUrls.forEach((url, index) => {
      console.log(`Image ${index + 1}: ${url}`);
    });
    
    // Process generated images
    // Can download images, save locally, etc.
    
  } else {
    // Task failed
    console.log('4o image generation failed:', msg);
    
    // Handle failure cases...
    if (code === 400) {
      console.log('Content policy violation or parameter error');
    } else if (code === 451) {
      console.log('Image 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');
});

Python

from flask import Flask, request, jsonify
import requests

app = Flask(__name__)

@app.route('/4o-image-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('taskId')
    info = callback_data.get('info')
    
    print(f"Received 4o image generation callback: {task_id}, status: {code}, message: {msg}")
    
    if code == 200:
        # Task completed successfully
        print("4o image generation completed")
        result_urls = info.get('result_urls', []) if info else []
        
        print(f"Generated {len(result_urls)} images:")
        for i, url in enumerate(result_urls):
            print(f"Image {i + 1}: {url}")
            
            # Download image example
            try:
                response = requests.get(url)
                if response.status_code == 200:
                    filename = f"4o_image_{task_id}_{i + 1}.png"
                    with open(filename, "wb") as f:
                        f.write(response.content)
                    print(f"Image saved as {filename}")
            except Exception as e:
                print(f"Image download failed: {e}")
                
    else:
        # Task failed
        print(f"4o image generation failed: {msg}")
        
        # Handle failure cases...
        if code == 400:
            print("Content policy violation or parameter error")
        elif code == 451:
            print("Image 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

<?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['taskId'] ?? '';
$info = $callbackData['info'] ?? null;

error_log("Received 4o image generation callback: $taskId, status: $code, message: $msg");

if ($code === 200) {
    // Task completed successfully
    error_log("4o image generation completed");
    $resultUrls = $info['result_urls'] ?? [];
    
    error_log("Generated " . count($resultUrls) . " images:");
    foreach ($resultUrls as $index => $url) {
        error_log("Image " . ($index + 1) . ": $url");
        
        // Download image example
        try {
            $imageContent = file_get_contents($url);
            if ($imageContent !== false) {
                $filename = "4o_image_{$taskId}_" . ($index + 1) . ".png";
                file_put_contents($filename, $imageContent);
                error_log("Image saved as $filename");
            }
        } catch (Exception $e) {
            error_log("Image download failed: " . $e->getMessage());
        }
    }
    
} else {
    // Task failed
    error_log("4o image generation failed: $msg");
    
    // Handle failure cases...
    if ($code === 400) {
        error_log("Content policy violation or parameter error");
    } elseif ($code === 451) {
        error_log("Image 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

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 taskId 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. Image Processing: Image 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 image URLs may have time limits, recommend downloading and saving promptly
• Pay attention to content policy compliance to avoid generation failures due to policy violations

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

Image Processing Issues

• Confirm that image URLs are accessible
• Check image download permissions and network connections
• Verify image save paths and permissions
• Note whether image content complies with content policies

Alternative Solution

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

Poll Query Results

Use the get 4o image details endpoint to regularly query task status. We recommend querying every 30 seconds.