Adjust Cross-Origin Resource Sharing (CORS) headers and handle preflight requests.
// Define CORS headersconst corsHeaders = { "Access-Control-Allow-Origin": "*", // Replace * with your allowed origin(s) "Access-Control-Allow-Methods": "GET, POST, PUT, DELETE, OPTIONS", // Adjust allowed methods as needed "Access-Control-Allow-Headers": "Content-Type, Authorization", // Adjust allowed headers as needed "Access-Control-Max-Age": "86400", // Adjust max age (in seconds) as needed}; export default { async fetch(request) { // Make a copy of the request to modify its headers const modifiedRequest = new Request(request); // Handle preflight requests (OPTIONS) if (request.method === "OPTIONS") { return new Response(null, { headers: { ...corsHeaders, }, status: 200, // Respond with OK status for preflight requests }); } // Pass the modified request through to the origin const response = await fetch(modifiedRequest); // Make a copy of the response to modify its headers const modifiedResponse = new Response(response.body, response); // Set CORS headers on the response Object.keys(corsHeaders).forEach((header) => { modifiedResponse.headers.set(header, corsHeaders[header]); }); return modifiedResponse; },};