fix auth conect

client/src/App.tsx

@@ -234,7 +234,6 @@ const App = () => {
   const onOAuthConnect = useCallback(
     (serverUrl: string) => {
       setSseUrl(serverUrl);
-      setTransportType("sse");
       setIsAuthDebuggerVisible(false);
       void connectMcpServer();
     },

client/src/lib/hooks/useConnection.ts

@@ -250,8 +250,12 @@ export function useConnection({
   };
 
   const handleAuthError = async (error: unknown) => {
-    if (error instanceof SseError && error.code === 401) {
-      // Create a new auth provider with the current server URL
+    const is401Error =
+      (error instanceof SseError && error.code === 401) ||
+      (error instanceof Error && error.message.includes('401')) ||
+      (error instanceof Error && error.message.includes('Unauthorized'));
+
+    if (is401Error) {
       const serverAuthProvider = new InspectorOAuthClientProvider(sseUrl);
 
       const result = await auth(serverAuthProvider, { serverUrl: sseUrl });
@@ -330,7 +334,6 @@ export function useConnection({
           mcpProxyServerUrl = new URL(`${getMCPProxyAddress(config)}/sse`);
           mcpProxyServerUrl.searchParams.append("url", sseUrl);
           transportOptions = {
-            authProvider: serverAuthProvider,
             eventSourceInit: {
               fetch: (
                 url: string | URL | globalThis.Request,
@@ -347,7 +350,6 @@ export function useConnection({
           mcpProxyServerUrl = new URL(`${getMCPProxyAddress(config)}/mcp`);
           mcpProxyServerUrl.searchParams.append("url", sseUrl);
           transportOptions = {
-            authProvider: serverAuthProvider,
             eventSourceInit: {
               fetch: (
                 url: string | URL | globalThis.Request,
@@ -375,9 +377,9 @@ export function useConnection({
       const clientTransport =
         transportType === "streamable-http"
           ? new StreamableHTTPClientTransport(mcpProxyServerUrl as URL, {
-              sessionId: undefined,
-              ...transportOptions,
-            })
+            sessionId: undefined,
+            ...transportOptions,
+          })
           : new SSEClientTransport(mcpProxyServerUrl as URL, transportOptions);
 
       if (onNotification) {
@@ -425,12 +427,19 @@ export function useConnection({
           `Failed to connect to MCP Server via the MCP Inspector Proxy: ${mcpProxyServerUrl}:`,
           error,
         );
-        const shouldRetry = await handleAuthError(error);
-        if (shouldRetry) {
-          return connect(undefined, retryCount + 1);
-        }
 
-        if (error instanceof SseError && error.code === 401) {
+        // Check for auth-related errors
+        const is401Error =
+          (error instanceof SseError && error.code === 401) ||
+          (error instanceof Error && error.message.includes('401')) ||
+          (error instanceof Error && error.message.includes('Unauthorized'));
+
+        if (is401Error) {
+          console.log("Detected 401 error, attempting OAuth flow");
+          const shouldRetry = await handleAuthError(error);
+          if (shouldRetry) {
+            return connect(undefined, retryCount + 1);
+          }
           // Don't set error state if we're about to redirect for auth
           return;
         }

package-lock.json

@@ -8407,15 +8407,6 @@
         "node": "20 || >=22"
       }
     },
-    "node_modules/path-to-regexp": {
-      "version": "8.2.0",
-      "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-8.2.0.tgz",
-      "integrity": "sha512-TdrF7fW9Rphjq4RjrW0Kp2AW0Ahwu9sRGTkS6bvDi0SCwZlEZYmcfDbEsTz8RVk0EHIS/Vd1bv3JhG+1xZuAyQ==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=16"
-      }
-    },
     "node_modules/picocolors": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",

server/src/mcpProxy.ts

@@ -1,4 +1,5 @@
 import { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
+import { isJSONRPCRequest } from "@modelcontextprotocol/sdk/types.js";
 
 function onClientError(error: Error) {
   console.error("Error from inspector client:", error);
@@ -19,7 +20,21 @@ export default function mcpProxy({
   let transportToServerClosed = false;
 
   transportToClient.onmessage = (message) => {
-    transportToServer.send(message).catch(onServerError);
+    transportToServer.send(message).catch((error) => {
+      // Send error response back to client if it was a request (has id) and connection is still open
+      if (isJSONRPCRequest(message) && !transportToClientClosed) {
+        const errorResponse = {
+          jsonrpc: "2.0" as const,
+          id: message.id,
+          error: {
+            code: -32001,
+            message: error.message,
+            data: error
+          }
+        };
+        transportToClient.send(errorResponse).catch(onClientError);
+      }
+    });
   };
 
   transportToServer.onmessage = (message) => {