> For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt.

# dev.mockDir

- **Type:** `string`
- **Default:** `'./config/mock'`

Sets the directory containing the Mock API entry file. Relative paths are
resolved from the application directory, and absolute paths are also supported.
Modern.js loads `index.ts` or `index.js` from this directory during development.

For example, move the Mock API entry to `mocks/index.ts`:

```js title="modern.config.ts"
import { defineConfig } from '@modern-js/app-tools';

export default defineConfig({
  dev: {
    mockDir: './mocks',
  },
});
```

This is also useful in a monorepo when multiple applications share one Mock
directory:

```js title="modern.config.ts"
export default defineConfig({
  dev: {
    mockDir: '../../shared/mocks',
  },
});
```