Server response 449 Retry With

Definition of HTTP Status Code 449

HTTP status code 449, known as "Retry With," is a non-standard response code utilized in specific scenarios where the server requires additional information from the client before processing the request. Although it is not part of the official HTTP standard, it may be encountered in certain APIs.

Situations for Returning Status Code 449

This status code is typically returned when:

• The server requires user authentication or authorization.
• Required parameters are missing from the client's request.
• Data validation errors occur during the request processing.

Examples of Using Status Code 449

Example 1: Authentication Requirement

In this scenario, a client attempts to access a restricted resource without providing valid authentication credentials. The server responds with status code 449, indicating that the client must include authentication information before retrying.

Request:
GET /protected/resource HTTP/1.1
Host: example.com

Response:
HTTP/1.1 449 Retry With
Content-Type: application/json

{"message": "Authentication required. Please provide valid credentials."}

Example 2: Missing Required Parameters

This example illustrates a situation where the client sends a request that lacks mandatory parameters needed for processing. The server responds with a 449 status code, prompting the client to resend the request with the required parameters.

Request:
POST /api/resource HTTP/1.1
Host: example.com
Content-Type: application/json

{"name": "Sample Item"}  

Response:
HTTP/1.1 449 Retry With
Content-Type: application/json

{"message": "Missing required parameter 'id'. Please include it and retry."}

Example 3: Data Validation Errors

In this case, the client submits data that fails validation rules set by the server. The server returns status code 449, indicating that the client should correct the errors and resend the request.

Request:
PUT /api/resource/1 HTTP/1.1
Host: example.com
Content-Type: application/json

{"id": 1, "quantity": -5}  

Response:
HTTP/1.1 449 Retry With
Content-Type: application/json

{"message": "Invalid data. 'quantity' must be a positive number."}

Handling Status Code 449 in Different Programming Languages

JavaScript (Node.js)

const axios = require('axios');

axios.post('/api/resource', { name: 'Sample Item' })
    .then(response => {
        console.log(response.data);
    })
    .catch(error => {
        if (error.response && error.response.status === 449) {
            console.log('Error:', error.response.data.message);
            // Include necessary data and retry
            return axios.post('/api/resource', { name: 'Sample Item', id: 1 });
        }
    });

Python (requests)

import requests

response = requests.post('http://example.com/api/resource', json={'name': 'Sample Item'})

if response.status_code == 449:
    print('Error:', response.json()['message'])
    # Add missing parameters and retry
    response = requests.post('http://example.com/api/resource', json={'name': 'Sample Item', 'id': 1})

PHP (cURL)

$ch = curl_init('http://example.com/api/resource');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode(['name' => 'Sample Item']));

$response = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

if ($httpCode == 449) {
    $errorData = json_decode($response, true);
    echo 'Error: ' . $errorData['message'];
    // Resend request with modified data
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode(['name' => 'Sample Item', 'id' => 1]));
    $response = curl_exec($ch);
}
curl_close($ch);

Recommendations for Working with Status Code 449

• Ensure proper handling of the 449 status code in client applications to enhance user experience.
• Implement logging mechanisms to track occurrences of this status code for better monitoring and debugging.

Scenario	Request Example	Response Example
Authentication Required	GET /protected/resource	HTTP/1.1 449 Retry With
Missing Required Parameters	POST /api/resource	HTTP/1.1 449 Retry With
Data Validation Error	PUT /api/resource/1	HTTP/1.1 449 Retry With

When dealing with status code 449, it’s crucial to remember that its utilization is not standardized across all servers. Thus, understanding how to respond appropriately based on specific server configurations and requirements is essential.