diff --git a/.claude/skills/certd/SKILL.md b/.claude/skills/certd/SKILL.md
new file mode 100644
index 000000000..cbcb460f6
--- /dev/null
+++ b/.claude/skills/certd/SKILL.md
@@ -0,0 +1,133 @@
+```markdown
+# certd Development Patterns
+
+> Auto-generated skill from repository analysis
+
+## Overview
+
+This skill teaches the core development patterns and workflows for the `certd` TypeScript codebase. It covers coding conventions, file organization, commit patterns, and detailed step-by-step instructions for extending user preferences—a common feature workflow. The repository is structured for modularity, with clear separation between UI and backend logic, and emphasizes maintainable, convention-driven development.
+
+## Coding Conventions
+
+### File Naming
+
+- **CamelCase** is used for file names.
+  - Example: `userPreferences.ts`, `preferencesDrawer.vue`
+
+### Import Style
+
+- **Absolute imports** are preferred.
+  - Example:
+    ```typescript
+    import { getUserPreferences } from 'packages/ui/certd-client/src/vben/layouts/widgets/preferences/api';
+    ```
+
+### Export Style
+
+- **Named exports** are used throughout the codebase.
+  - Example:
+    ```typescript
+    export function getUserPreferences() { ... }
+    export const PREFERENCE_KEYS = [ ... ];
+    ```
+
+### Commit Patterns
+
+- **Conventional commits** are used, with the `feat` prefix for new features.
+  - Example:
+    ```
+    feat: add account sync to preferences
+    ```
+
+## Workflows
+
+### Extend Preferences Feature
+
+**Trigger:** When someone wants to add or enhance a user preference feature (e.g., import/export, sync to account).  
+**Command:** `/extend-preferences`
+
+Follow these steps to extend user preferences functionality:
+
+1. **Update localization files**  
+   Add or modify strings in:
+   - `packages/ui/certd-client/src/locales/langs/en-US/preferences.ts`
+   - `packages/ui/certd-client/src/locales/langs/zh-CN/preferences.ts`
+   ```typescript
+   // en-US/preferences.ts
+   export default {
+     sync: "Sync Preferences",
+     import: "Import Preferences",
+     // ...
+   };
+   ```
+
+2. **Modify or add Vue components for preferences UI**  
+   Update or create components such as:
+   - `preferences-drawer.vue`
+   - `account-sync.ts`
+   ```vue
+   <!-- preferences-drawer.vue -->
+   <template>
+     <div>
+       <button @click="syncPreferences">{{ $t('preferences.sync') }}</button>
+     </div>
+   </template>
+   ```
+
+3. **Update or add supporting icon definitions**  
+   Edit:
+   - `packages/ui/certd-client/src/vben/icons/lucide.ts`
+   ```typescript
+   export const SyncIcon = { /* icon definition */ };
+   ```
+
+4. **Implement or update store logic for settings**  
+   Update:
+   - `packages/ui/certd-client/src/store/settings/index.tsx`
+   ```typescript
+   export function syncPreferencesToAccount() { ... }
+   ```
+
+5. **Add or update backend API/controller for user preferences**  
+   Edit or add:
+   - `packages/ui/certd-client/src/vben/layouts/widgets/preferences/api.ts`
+   - `packages/ui/certd-server/src/controller/user/mine/user-preferences.ts`
+   ```typescript
+   // user-preferences.ts
+   export async function updateUserPreferences(req, res) { ... }
+   ```
+
+6. **Write or update backend tests for new preference logic**  
+   Add or update:
+   - `packages/ui/certd-server/src/controller/user/mine/user-preferences.test.ts`
+   ```typescript
+   test('should sync preferences', async () => { ... });
+   ```
+
+7. **Update backend models if necessary**  
+   Edit:
+   - `packages/ui/certd-server/src/modules/mine/service/models.ts`
+   ```typescript
+   export interface UserPreferences { ... }
+   ```
+
+## Testing Patterns
+
+- **Test files** follow the `*.test.*` naming convention.
+  - Example: `user-preferences.test.ts`
+- **Testing framework** is not explicitly detected, but tests are written in TypeScript and likely use a standard Node.js testing library (e.g., Jest or Mocha).
+- **Test Example:**
+  ```typescript
+  test('should update preferences', async () => {
+    // Arrange
+    // Act
+    // Assert
+  });
+  ```
+
+## Commands
+
+| Command              | Purpose                                                      |
+|----------------------|--------------------------------------------------------------|
+| /extend-preferences  | Guide to extend or enhance user preference functionality     |
+```