Merge pull request modelcontextprotocol#81 from modelcontextprotocol/ashwin/serverport

Respect custom server port

Author: ashwin-ant

bin/cli.js

@@ -61,8 +61,9 @@ async function main() {
 
   // Make sure our server/client didn't immediately fail
   await Promise.any([server, client, delay(2 * 1000)]);
+  const portParam = SERVER_PORT === "3000" ? "" : `?proxyPort=${SERVER_PORT}`;
   console.log(
-    `\n🔍 MCP Inspector is up and running at http://localhost:${CLIENT_PORT} 🚀`,
+    `\n🔍 MCP Inspector is up and running at http://localhost:${CLIENT_PORT}${portParam} 🚀`,
   );
 
   try {

client/src/App.tsx

@@ -57,6 +57,10 @@ import ToolsTab from "./components/ToolsTab";
 
 const DEFAULT_REQUEST_TIMEOUT_MSEC = 10000;
 
+const params = new URLSearchParams(window.location.search);
+const PROXY_PORT = params.get("proxyPort") ?? "3000";
+const PROXY_SERVER_URL = `http://localhost:${PROXY_PORT}`;
+
 const App = () => {
   const [connectionStatus, setConnectionStatus] = useState<
     "disconnected" | "connected" | "error"
@@ -82,7 +86,8 @@ const App = () => {
   const [args, setArgs] = useState<string>(() => {
     return localStorage.getItem("lastArgs") || "";
   });
-  const [url, setUrl] = useState<string>("http://localhost:3001/sse");
+
+  const [sseUrl, setSseUrl] = useState<string>("http://localhost:3001/sse");
   const [transportType, setTransportType] = useState<"stdio" | "sse">("stdio");
   const [requestHistory, setRequestHistory] = useState<
     { request: string; response?: string }[]
@@ -191,7 +196,7 @@ const App = () => {
   }, [args]);
 
   useEffect(() => {
-    fetch("http://localhost:3000/config")
+    fetch(`${PROXY_SERVER_URL}/config`)
       .then((response) => response.json())
       .then((data) => {
         setEnv(data.defaultEnvironment);
@@ -404,15 +409,15 @@ const App = () => {
         },
       );
 
-      const backendUrl = new URL("http://localhost:3000/sse");
+      const backendUrl = new URL(`${PROXY_SERVER_URL}/sse`);
 
       backendUrl.searchParams.append("transportType", transportType);
       if (transportType === "stdio") {
         backendUrl.searchParams.append("command", command);
         backendUrl.searchParams.append("args", args);
         backendUrl.searchParams.append("env", JSON.stringify(env));
       } else {
-        backendUrl.searchParams.append("url", url);
+        backendUrl.searchParams.append("url", sseUrl);
       }
 
       const clientTransport = new SSEClientTransport(backendUrl);
@@ -469,8 +474,8 @@ const App = () => {
         setCommand={setCommand}
         args={args}
         setArgs={setArgs}
-        url={url}
-        setUrl={setUrl}
+        sseUrl={sseUrl}
+        setSseUrl={setSseUrl}
         env={env}
         setEnv={setEnv}
         onConnect={connectMcpServer}

client/src/components/Sidebar.tsx

@@ -22,8 +22,8 @@ interface SidebarProps {
   setCommand: (command: string) => void;
   args: string;
   setArgs: (args: string) => void;
-  url: string;
-  setUrl: (url: string) => void;
+  sseUrl: string;
+  setSseUrl: (url: string) => void;
   env: Record<string, string>;
   setEnv: (env: Record<string, string>) => void;
   onConnect: () => void;
@@ -38,8 +38,8 @@ const Sidebar = ({
   setCommand,
   args,
   setArgs,
-  url,
-  setUrl,
+  sseUrl,
+  setSseUrl,
   env,
   setEnv,
   onConnect,
@@ -75,6 +75,7 @@ const Sidebar = ({
               </SelectContent>
             </Select>
           </div>
+
           {transportType === "stdio" ? (
             <>
               <div className="space-y-2">
@@ -99,8 +100,8 @@ const Sidebar = ({
               <label className="text-sm font-medium">URL</label>
               <Input
                 placeholder="URL"
-                value={url}
-                onChange={(e) => setUrl(e.target.value)}
+                value={sseUrl}
+                onChange={(e) => setSseUrl(e.target.value)}
               />
             </div>
           )}