diff --git a/ui/desktop/src/components/settings/extensions/subcomponents/ExtensionList.tsx b/ui/desktop/src/components/settings/extensions/subcomponents/ExtensionList.tsx
index d42b94baa055..288c1c5f56a5 100644
--- a/ui/desktop/src/components/settings/extensions/subcomponents/ExtensionList.tsx
+++ b/ui/desktop/src/components/settings/extensions/subcomponents/ExtensionList.tsx
@@ -2,6 +2,7 @@ import ExtensionItem from './ExtensionItem';
 import builtInExtensionsData from '../../../../built-in-extensions.json';
 import { ExtensionConfig } from '../../../../api';
 import { FixedExtensionEntry } from '../../../ConfigContext';
+import { combineCmdAndArgs } from '../utils';
 
 interface ExtensionListProps {
   extensions: FixedExtensionEntry[];
@@ -137,7 +138,7 @@ export function getSubtitle(config: ExtensionConfig) {
     default:
       return {
         description: config.description || null,
-        command: 'cmd' in config ? [config.cmd, ...config.args].join(' ') : null,
+        command: 'cmd' in config ? combineCmdAndArgs(config.cmd, config.args) : null,
       };
   }
 }
diff --git a/ui/desktop/src/components/settings/extensions/utils.test.ts b/ui/desktop/src/components/settings/extensions/utils.test.ts
index 8888e6833e73..ab886aa173e8 100644
--- a/ui/desktop/src/components/settings/extensions/utils.test.ts
+++ b/ui/desktop/src/components/settings/extensions/utils.test.ts
@@ -156,6 +156,85 @@ describe('Extension Utils', () => {
         headers: [],
       });
     });
+
+    it('should not escape @ in command args', () => {
+      const extension: FixedExtensionEntry = {
+        type: 'stdio',
+        name: 'context7',
+        description: 'Context7 MCP',
+        cmd: 'npx',
+        args: ['-y', '@upstash/context7-mcp'],
+        enabled: true,
+      };
+
+      const formData = extensionToFormData(extension);
+      expect(formData.cmd).toBe('npx -y @upstash/context7-mcp');
+    });
+
+    it('should quote args with spaces', () => {
+      const extension: FixedExtensionEntry = {
+        type: 'stdio',
+        name: 'java-app',
+        description: 'Java app',
+        cmd: '/Applications/IntelliJ IDEA.app/Contents/jbr/Contents/Home/bin/java',
+        args: ['-classpath', '/path/with spaces/lib.jar', 'Main'],
+        enabled: true,
+      };
+
+      const formData = extensionToFormData(extension);
+      expect(formData.cmd).toBe(
+        '"/Applications/IntelliJ IDEA.app/Contents/jbr/Contents/Home/bin/java" -classpath "/path/with spaces/lib.jar" Main'
+      );
+    });
+
+    it('should roundtrip command with @ through form data', () => {
+      const extension: FixedExtensionEntry = {
+        type: 'stdio',
+        name: 'context7',
+        description: 'Context7 MCP',
+        cmd: 'npx',
+        args: ['-y', '@upstash/context7-mcp'],
+        enabled: true,
+      };
+
+      const formData = extensionToFormData(extension);
+      const { cmd, args } = splitCmdAndArgs(formData.cmd || '');
+      expect(cmd).toBe('npx');
+      expect(args).toEqual(['-y', '@upstash/context7-mcp']);
+    });
+
+    it('should roundtrip command with spaces through form data', () => {
+      const extension: FixedExtensionEntry = {
+        type: 'stdio',
+        name: 'java-app',
+        description: 'Java app',
+        cmd: '/Applications/IntelliJ IDEA.app/Contents/jbr/Contents/Home/bin/java',
+        args: ['-classpath', '/path/with spaces/lib.jar', 'Main'],
+        enabled: true,
+      };
+
+      const formData = extensionToFormData(extension);
+      const { cmd, args } = splitCmdAndArgs(formData.cmd || '');
+      expect(cmd).toBe('/Applications/IntelliJ IDEA.app/Contents/jbr/Contents/Home/bin/java');
+      expect(args).toEqual(['-classpath', '/path/with spaces/lib.jar', 'Main']);
+    });
+
+    it('should roundtrip args with double quotes and spaces through form data', () => {
+      const extension: FixedExtensionEntry = {
+        type: 'stdio',
+        name: 'test',
+        description: 'test',
+        cmd: 'node',
+        args: ['/My "Project"/bin/run'],
+        enabled: true,
+      };
+
+      const formData = extensionToFormData(extension);
+      expect(formData.cmd).toBe('node \'/My "Project"/bin/run\'');
+      const { cmd, args } = splitCmdAndArgs(formData.cmd || '');
+      expect(cmd).toBe('node');
+      expect(args).toEqual(['/My "Project"/bin/run']);
+    });
   });
 
   describe('createExtensionConfig', () => {
diff --git a/ui/desktop/src/components/settings/extensions/utils.ts b/ui/desktop/src/components/settings/extensions/utils.ts
index 3ea8bb04cff0..00e29c1fa506 100644
--- a/ui/desktop/src/components/settings/extensions/utils.ts
+++ b/ui/desktop/src/components/settings/extensions/utils.ts
@@ -1,6 +1,6 @@
 import type { FixedExtensionEntry } from '../../ConfigContext';
 import type { ExtensionConfig } from '../../../api/types.gen';
-import { parse as parseShellQuote, quote as quoteShell } from 'shell-quote';
+import { parse as parseShellQuote } from 'shell-quote';
 
 // Default extension timeout in seconds
 // TODO: keep in sync with rust better
@@ -100,11 +100,11 @@ export function extensionToFormData(extension: FixedExtensionEntry): ExtensionFo
     description: extension.description || '',
     type:
       extension.type === 'frontend' ||
-        extension.type === 'inline_python' ||
-        extension.type === 'platform'
+      extension.type === 'inline_python' ||
+      extension.type === 'platform'
         ? 'stdio'
         : extension.type,
-    cmd: extension.type === 'stdio' ? quoteShell([extension.cmd, ...extension.args]) : undefined,
+    cmd: extension.type === 'stdio' ? combineCmdAndArgs(extension.cmd, extension.args) : undefined,
     endpoint:
       extension.type === 'streamable_http' || extension.type === 'sse'
         ? (extension.uri ?? undefined)
@@ -187,7 +187,13 @@ export function splitCmdAndArgs(str: string): { cmd: string; args: string[] } {
 }
 
 export function combineCmdAndArgs(cmd: string, args: string[]): string {
-  return quoteShell([cmd, ...args]);
+  return [cmd, ...args]
+    .map((a) => {
+      if (!a.includes(' ')) return a;
+      if (a.includes('"')) return `'${a}'`;
+      return `"${a}"`;
+    })
+    .join(' ');
 }
 
 export function extractCommand(link: string): string {