Merge pull request #5493 from 04cfb1ed/feature/add-headers-to-mcp

feat: add support for custom headers in SSE transport

Author: sestinj

core/context/mcp/MCPConnection.test.ts

@@ -55,6 +55,27 @@ describe("MCPConnection", () => {
       expect(conn.status).toBe("not-connected");
     });
 
+    it("should create instance with SSE transport and custom headers", () => {
+      const options = {
+        name: "test-mcp",
+        id: "test-id",
+        transport: {
+          type: "sse" as const,
+          url: "http://test.com/events",
+          requestOptions: {
+            headers: {
+              "Authorization": "Bearer token123",
+              "X-Custom-Header": "custom-value"
+            }
+          }
+        },
+      };
+
+      const conn = new MCPConnection(options);
+      expect(conn).toBeInstanceOf(MCPConnection);
+      expect(conn.status).toBe("not-connected");
+    });
+
     it("should throw on invalid transport type", () => {
       const options = {
         name: "test-mcp",

core/context/mcp/MCPConnection.ts

@@ -69,7 +69,19 @@ class MCPConnection {
       case "websocket":
         return new WebSocketClientTransport(new URL(options.transport.url));
       case "sse":
-        return new SSEClientTransport(new URL(options.transport.url));
+        return new SSEClientTransport(new URL(options.transport.url), {
+          eventSourceInit: {
+            fetch: (input, init) =>
+              fetch(input, {
+                ...init,
+                headers: {
+                  ...init?.headers,
+                  ...(options.transport.requestOptions?.headers as Record<string, string> | undefined),
+                }
+              }),
+          },
+          requestInit: { headers: options.transport.requestOptions?.headers }
+        });
       default:
         throw new Error(
           `Unsupported transport type: ${(options.transport as any).type}`,

core/index.d.ts

@@ -1115,16 +1115,19 @@ export interface StdioOptions {
   command: string;
   args: string[];
   env?: Record<string, string>;
+  requestOptions?: RequestOptions;
 }
 
 export interface WebSocketOptions {
   type: "websocket";
   url: string;
+  requestOptions?: RequestOptions;
 }
 
 export interface SSEOptions {
   type: "sse";
   url: string;
+  requestOptions?: RequestOptions;
 }
 
 export type TransportOptions = StdioOptions | WebSocketOptions | SSEOptions;