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

# output.ssg

- **Type:** `boolean | object`
- **Default Value:** `undefined`

Configuration to enable the application’s SSG (Static Site Generation) feature.

:::tip Enabling SSG
This configuration takes effect only when SSG is enabled. Please read the [Static Site Generation](/guides/basic-features/render/ssg.md) documentation to understand how to enable SSG and its use cases.

:::

:::info Recommended Reading
The SSG feature is closely related to routing. It is recommended to understand the [routing solution](/guides/basic-features/routes/routes.md) before using SSG.

:::

:::info

- Use `output.ssg` for single-entry apps.
- For multi-entry apps, prefer `output.ssgByEntries`.
- If `output.ssg` is `true` and `output.ssgByEntries` is not set, all routes under all entries are treated as SSG routes.

:::

## Boolean Type

When this configuration is set to `true`, the SSG feature will be enabled for all entries by default. For **manual routing**, the root route of the entry will be rendered. For **conventional routing**, each route in the entry will be rendered.

```js
export default defineConfig({
  output: {
    ssg: true,
  },
});
```

## Object Type

When the value type is `Object`, the following attributes can be configured.

### Configuration Type

```ts
type SSGRouteOptions =
  | string
  | {
      url: string;
      headers?: Record<string, any>;
    };

type SSGOptions = {
  headers?: Record<string, any>;
  routes?: SSGRouteOptions[];
};
```

### Example

In the example configuration below, SSG will render the pages corresponding to the `/`, `/about`, and `/user/:id` routes.

For the `/user/:id` route, `cookies` will be added to the request headers.

```ts title="modern.config.ts"
export default defineConfig({
  output: {
    ssg: {
      routes: [
        '/',
        '/about',
        {
          url: '/user/modernjs',
          headers: {
            cookies: 'name=modernjs',
          },
        },
      ],
    },
  },
});
```