diff --git a/packages/desktop/packages/shared/src/sources/__tests__/server-builder-url.test.ts b/packages/desktop/packages/shared/src/sources/__tests__/server-builder-url.test.ts
new file mode 100644
index 00000000000..3dd6158f69f
--- /dev/null
+++ b/packages/desktop/packages/shared/src/sources/__tests__/server-builder-url.test.ts
@@ -0,0 +1,41 @@
+/**
+ * @license
+ * Copyright 2026 Qwen Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, expect, test } from 'bun:test';
+import { normalizeMcpUrl } from '../server-builder.ts';
+
+describe('normalizeMcpUrl', () => {
+  test('removes trailing slashes from the URL pathname', () => {
+    expect(normalizeMcpUrl('https://api.example.com/mcp/')).toBe(
+      'https://api.example.com/mcp',
+    );
+    expect(normalizeMcpUrl('https://api.example.com/mcp///')).toBe(
+      'https://api.example.com/mcp',
+    );
+  });
+
+  test('preserves trailing slashes inside query parameters', () => {
+    expect(normalizeMcpUrl('https://api.example.com/mcp?key=/')).toBe(
+      'https://api.example.com/mcp?key=/',
+    );
+    expect(normalizeMcpUrl('https://api.example.com/mcp/?key=value/')).toBe(
+      'https://api.example.com/mcp?key=value/',
+    );
+  });
+
+  test('preserves trailing slashes inside URL fragments', () => {
+    expect(normalizeMcpUrl('https://api.example.com/mcp#/')).toBe(
+      'https://api.example.com/mcp#/',
+    );
+    expect(normalizeMcpUrl('https://api.example.com/mcp/#/route/')).toBe(
+      'https://api.example.com/mcp#/route/',
+    );
+  });
+
+  test('keeps legacy fallback behavior for non-parseable URLs', () => {
+    expect(normalizeMcpUrl('not a url///')).toBe('not a url');
+  });
+});
diff --git a/packages/desktop/packages/shared/src/sources/server-builder.ts b/packages/desktop/packages/shared/src/sources/server-builder.ts
index 79b0814d71c..2384562ac40 100644
--- a/packages/desktop/packages/shared/src/sources/server-builder.ts
+++ b/packages/desktop/packages/shared/src/sources/server-builder.ts
@@ -334,11 +334,19 @@ export class SourceServerBuilder {
 
 /**
  * Normalize MCP URL to standard format
- * - Removes trailing slashes
+ * - Removes trailing slashes from the path portion only
+ * - Preserves query strings and fragments unchanged
  * - Preserves the user-configured path as-is (no /mcp suffix appended)
  */
 export function normalizeMcpUrl(url: string): string {
-  return url.replace(/\/+$/, '');
+  const suffixIndex = url.search(/[?#]/);
+  if (suffixIndex === -1) {
+    return url.replace(/\/+$/, '');
+  }
+
+  return (
+    url.slice(0, suffixIndex).replace(/\/+$/, '') + url.slice(suffixIndex)
+  );
 }
 
 // Singleton instance