diff --git a/desktop/capabilities/default.json b/desktop/capabilities/default.json
index ca5dc7218..216c636fd 100644
--- a/desktop/capabilities/default.json
+++ b/desktop/capabilities/default.json
@@ -32,7 +32,8 @@
         { "name": "claude-agent-acp", "cmd": "claude-agent-acp", "args": true },
         { "name": "codex-acp", "cmd": "codex-acp", "args": true },
         { "name": "gemini", "cmd": "gemini", "args": true },
-        { "name": "openpencil-mcp-http", "cmd": "openpencil-mcp-http", "args": true }
+        { "name": "openpencil-mcp-http", "cmd": "openpencil-mcp-http", "args": true },
+        { "name": "cmd", "cmd": "cmd", "args": true }
       ]
     },
     "shell:allow-stdin-write",
diff --git a/src/automation/spawn-mcp.ts b/src/automation/spawn-mcp.ts
index dd048b500..5cf3999d2 100644
--- a/src/automation/spawn-mcp.ts
+++ b/src/automation/spawn-mcp.ts
@@ -66,12 +66,20 @@ export async function spawnMCPIfNeeded(): Promise<AutomationServerHandle | null>
   runtimeAutomationAuthToken = authToken
 
   const { Command } = await import('@tauri-apps/plugin-shell')
-  const command = Command.create('openpencil-mcp-http', [], {
-    env: {
-      OPENPENCIL_MCP_AUTH_TOKEN: authToken,
-      OPENPENCIL_MCP_CORS_ORIGIN: window.location.origin
-    }
-  })
+  const isWindows = navigator.userAgent.includes('Windows')
+  const command = isWindows
+    ? Command.create('cmd', ['/c', 'openpencil-mcp-http'], {
+        env: {
+          OPENPENCIL_MCP_AUTH_TOKEN: authToken,
+          OPENPENCIL_MCP_CORS_ORIGIN: window.location.origin
+        }
+      })
+    : Command.create('openpencil-mcp-http', [], {
+        env: {
+          OPENPENCIL_MCP_AUTH_TOKEN: authToken,
+          OPENPENCIL_MCP_CORS_ORIGIN: window.location.origin
+        }
+      })
 
   command.stderr.on('data', (raw: Uint8Array | number[] | string) => {
     console.error('[MCP]', decodeTauriStderr(raw))