Fix/cors (#71)

* fix: cors headers

* fix: CORS

Author: idosal

src/index.ts

@@ -20,6 +20,35 @@ const requestHandler = createRequestHandler(
   import.meta.env.MODE,
 );
 
+// Helper function to add CORS headers to a response
+const addCorsHeaders = (response: Response): Response => {
+  const headers = new Headers(response.headers);
+  headers.set("Access-Control-Allow-Origin", "http://localhost:5173");
+  headers.set("Access-Control-Allow-Methods", "GET, POST, OPTIONS");
+  headers.set("Access-Control-Allow-Headers", "Content-Type, Authorization");
+  headers.set("Access-Control-Allow-Credentials", "true");
+
+  return new Response(response.body, {
+    status: response.status,
+    statusText: response.statusText,
+    headers,
+  });
+};
+
+// Create CORS preflight response
+const handleCorsPreflightRequest = (): Response => {
+  return new Response(null, {
+    status: 204, // No content
+    headers: {
+      "Access-Control-Allow-Origin": "*",
+      "Access-Control-Allow-Methods": "GET, POST, OPTIONS",
+      "Access-Control-Allow-Headers": "Content-Type",
+      "Access-Control-Allow-Credentials": "true",
+      "Access-Control-Max-Age": "86400", // 24 hours
+    },
+  });
+};
+
 export class MyMCP extends McpAgent {
   server = new McpServer({
     name: "GitMCP",
@@ -67,6 +96,11 @@ const mcpHandler = MyMCP.mount("/*");
 // Export a request handler that checks the transport header
 export default {
   async fetch(request: Request, env: any, ctx: any) {
+    // Handle CORS preflight requests
+    if (request.method === "OPTIONS") {
+      return handleCorsPreflightRequest();
+    }
+
     const url = new URL(request.url);
     const isSse =
       request.headers.get("accept")?.includes("text/event-stream") &&