👀 Views: 361 💬 Answers: 1 📅 Created: 2025-06-13

jquery ajax cors JavaScript

After trying multiple solutions online, I still can't figure this out. I'm maintaining legacy code that I can't seem to get I'm building a feature where This might be a silly question, but I've looked through the documentation and I'm still confused about I'm working with an scenario with jQuery's `.ajax()` method where my requests to a different domain are failing due to CORS preflight checks... I am trying to send a POST request to my API endpoint, but it seems to be failing on the OPTIONS request before the actual POST is sent. Here's a snippet of my AJAX call: ```javascript $.ajax({ url: 'https://api.example.com/data', type: 'POST', contentType: 'application/json', data: JSON.stringify({ key: 'value' }), headers: { 'Custom-Header': 'myValue' }, success: function(response) { console.log('Success:', response); }, behavior: function(xhr, status, behavior) { console.behavior('behavior:', status, behavior); } }); ``` When I inspect the network requests in Chrome, I see the OPTIONS request being sent, but it gets blocked due to CORS policy, and I see the following behavior in the console: ``` Access to fetch at 'https://api.example.com/data' from origin 'https://mywebsite.com' has been blocked by CORS policy: The 'Access-Control-Allow-Headers' header contains 'Custom-Header', which is not allowed. ``` I've tried adding appropriate headers to my server-side CORS configuration, but it still doesn't seem to be working. Here's the CORS configuration on my server (Node.js with Express): ```javascript app.use((req, res, next) => { res.header('Access-Control-Allow-Origin', 'https://mywebsite.com'); res.header('Access-Control-Allow-Headers', 'Custom-Header, Content-Type'); res.header('Access-Control-Allow-Methods', 'GET, POST, OPTIONS'); next(); }); ``` I've confirmed that the server is running and accessible, and I've also checked that my browser has no extensions interfering with CORS policies. Could this be a matter of the server not responding correctly to the OPTIONS request, or is there something I'm missing in the AJAX setup? Any guidance on how to resolve this would be greatly appreciated! This is part of a larger web app I'm building. Is there a better approach? I'd really appreciate any guidance on this. I'm working on a web app that needs to handle this. Thanks, I really appreciate it! I recently upgraded to Javascript 3.9. Any help would be greatly appreciated! For reference, this is a production web app.