Add loading state for Connect/Restart buttons

client/src/components/Sidebar.tsx

@@ -108,8 +108,30 @@ const Sidebar = ({
   const [shownEnvVars, setShownEnvVars] = useState<Set<string>>(new Set());
   const [copiedServerEntry, setCopiedServerEntry] = useState(false);
   const [copiedServerFile, setCopiedServerFile] = useState(false);
+  const [isConnecting, setIsConnecting] = useState(false);
   const { toast } = useToast();
 
+  // Wrapper for onConnect that manages loading state
+  const handleConnect = useCallback(async () => {
+    try {
+      setIsConnecting(true);
+      await onConnect();
+    } finally {
+      setIsConnecting(false);
+    }
+  }, [onConnect]);
+
+  // Wrapper for restart that manages loading state
+  const handleRestart = useCallback(async () => {
+    try {
+      setIsConnecting(true);
+      onDisconnect();
+      await onConnect();
+    } finally {
+      setIsConnecting(false);
+    }
+  }, [onConnect, onDisconnect]);
+
   // Reusable error reporter for copy actions
   const reportError = useCallback(
     (error: unknown) => {
@@ -676,10 +698,8 @@ const Sidebar = ({
               <div className="grid grid-cols-2 gap-4">
                 <Button
                   data-testid="connect-button"
-                  onClick={() => {
-                    onDisconnect();
-                    onConnect();
-                  }}
+                  onClick={handleRestart}
+                  loading={isConnecting}
                 >
                   <RotateCcw className="w-4 h-4 mr-2" />
                   {transportType === "stdio" ? "Restart" : "Reconnect"}
@@ -691,7 +711,11 @@ const Sidebar = ({
               </div>
             )}
             {connectionStatus !== "connected" && (
-              <Button className="w-full" onClick={onConnect}>
+              <Button
+                className="w-full"
+                onClick={handleConnect}
+                loading={isConnecting}
+              >
                 <Play className="w-4 h-4 mr-2" />
                 Connect
               </Button>

client/src/components/ui/button.tsx

@@ -38,17 +38,77 @@ export interface ButtonProps
   extends React.ButtonHTMLAttributes<HTMLButtonElement>,
     VariantProps<typeof buttonVariants> {
   asChild?: boolean;
+  loading?: boolean;
+  loadingText?: string;
 }
 
+const LoadingSpinner = () => (
+  <svg
+    className="animate-spin -ml-1 mr-2 h-4 w-4 text-current"
+    xmlns="http://www.w3.org/2000/svg"
+    fill="none"
+    viewBox="0 0 24 24"
+  >
+    <circle
+      className="opacity-25"
+      cx="12"
+      cy="12"
+      r="10"
+      stroke="currentColor"
+      strokeWidth="4"
+    ></circle>
+    <path
+      className="opacity-75"
+      fill="currentColor"
+      d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"
+    ></path>
+  </svg>
+);
+
 const Button = React.forwardRef<HTMLButtonElement, ButtonProps>(
-  ({ className, variant, size, asChild = false, ...props }, ref) => {
+  (
+    {
+      className,
+      variant,
+      size,
+      asChild = false,
+      loading = false,
+      loadingText = "Loading...",
+      children,
+      ...props
+    },
+    ref,
+  ) => {
     const Comp = asChild ? Slot : "button";
+
+    if (asChild) {
+      return (
+        <Comp
+          className={cn(buttonVariants({ variant, size, className }))}
+          ref={ref}
+          {...props}
+        >
+          {children}
+        </Comp>
+      );
+    }
+
     return (
       <Comp
         className={cn(buttonVariants({ variant, size, className }))}
+        disabled={loading || props.disabled}
         ref={ref}
         {...props}
-      />
+      >
+        {loading ? (
+          <>
+            <LoadingSpinner />
+            {loadingText}
+          </>
+        ) : (
+          children
+        )}
+      </Comp>
     );
   },
 );