---
url: >-
  https://lit-ui-router.dev/reference/ui-router-server/vite/interfaces/ServerRouterPluginOptions.md
---
[ui-router-server](../../index.md) / [vite](../index.md) / ServerRouterPluginOptions

# Interface: ServerRouterPluginOptions

Defined in: [vite.ts:135](https://github.com/simshanith/lit-ui-router/blob/740888c2b2ba358c4dfa52a122e927df6a604b12/packages/ui-router-server/src/vite.ts#L135)

Options for [serverRouterPlugin](../functions/serverRouterPlugin.md): the Connect adapter's, plus the build step; the base comes from Vite's config.

## Extends

* [`ConnectAdapterOptions`](../../connect/interfaces/ConnectAdapterOptions.md)

## Properties

| Property | Type | Description | Overrides | Inherited from | Defined in |
| ------ | ------ | ------ | ------ | ------ | ------ |
|  `base?` | `string` | Checked against Vite's resolved `base`, which the router's `base` sets when Vite's is unset; a different value throws. | [`ConnectAdapterOptions`](../../connect/interfaces/ConnectAdapterOptions.md).[`base`](../../connect/interfaces/ConnectAdapterOptions.md#base) | - | [vite.ts:137](https://github.com/simshanith/lit-ui-router/blob/740888c2b2ba358c4dfa52a122e927df6a604b12/packages/ui-router-server/src/vite.ts#L137) |
|  `delegates?` | `"next"` | How delegating states are served. Connect has no fetch-shaped handler bridge, so `'next'` is the only mode: a navigation that matches a delegating state passes to the downstream stack, which must serve it. Without it, construction throws for a router from `createServerRouter` that names delegate keys, and a structural router's delegate verdict fails the request through `next(error)`. | - | [`ConnectAdapterOptions`](../../connect/interfaces/ConnectAdapterOptions.md).[`delegates`](../../connect/interfaces/ConnectAdapterOptions.md#delegates) | [connect.ts:140](https://github.com/simshanith/lit-ui-router/blob/740888c2b2ba358c4dfa52a122e927df6a604b12/packages/ui-router-server/src/connect.ts#L140) |
|  `prerender?` | `string` | [`PrerenderOptions`](PrerenderOptions.md) | Prerenders the app after `vite build`. `entry` names the prerender script, resolved against Vite's root, whose default export is a [PrerenderEntry](../type-aliases/PrerenderEntry.md); a string is shorthand for `{ entry }`. The script runs in a `worker_thread` of its own, after any [preload](PrerenderOptions.md#preload) modules, so nothing it installs reaches Vite's process. It is loaded through a Vite module runner with the root and mode, without the app's plugins, and its dependencies load from node. `vite preview` then serves each page the build wrote, and `404.html` for a path the `otherwise` rule sends to a 404 state, while redirects and plain 404s still answer through the middleware. A [serveShell](../../connect/interfaces/ConnectAdapterOptions.md#serveshell) passed here replaces that. **See** https://lit-ui-router.dev/guides/prerender-with-vite | - | - | [vite.ts:156](https://github.com/simshanith/lit-ui-router/blob/740888c2b2ba358c4dfa52a122e927df6a604b12/packages/ui-router-server/src/vite.ts#L156) |
|  `responses?` | `"next"` | How response states are served, as for [delegates](../../connect/interfaces/ConnectAdapterOptions.md#delegates): `'next'` passes a navigation that matches one to the downstream stack, which must answer it. Without it, construction throws for a router from `createServerRouter` that declares response states, and a structural router's response verdict fails the request through `next(error)`. | - | [`ConnectAdapterOptions`](../../connect/interfaces/ConnectAdapterOptions.md).[`responses`](../../connect/interfaces/ConnectAdapterOptions.md#responses) | [connect.ts:148](https://github.com/simshanith/lit-ui-router/blob/740888c2b2ba358c4dfa52a122e927df6a604b12/packages/ui-router-server/src/connect.ts#L148) |
|  `serveNotFound?` | (`mount`, `req`, `res`, `next`) => `void` | Serve a mount-owned miss (`notFound` with a mount: the mount owned the pathname but no route matched). The default answers a minimal `text/plain` 404 — override to serve a real 404 page. A `notFound` without a mount is never routed here: the pathname isn't this router's, so the middleware always passes it through untouched. | - | [`ConnectAdapterOptions`](../../connect/interfaces/ConnectAdapterOptions.md).[`serveNotFound`](../../connect/interfaces/ConnectAdapterOptions.md#servenotfound) | [connect.ts:116](https://github.com/simshanith/lit-ui-router/blob/740888c2b2ba358c4dfa52a122e927df6a604b12/packages/ui-router-server/src/connect.ts#L116) |
|  `serveShell?` | (`mount`, `req`, `res`, `next`, `verdict`) => `void` | Serve the mount's shell. The default rewrites `req.url` to [shellPath](../../connect/interfaces/ConnectAdapterOptions.md#shellpath) and `next()`s into the downstream static layer. By the time this runs the adapter has already done the status'd-shell mechanics: request validators stripped and the response relabeled to the verdict's status — a host override only owns the asset IO. The verdict arrives last, so a host can serve a 404 page for the `otherwise` projection's `status`. | - | [`ConnectAdapterOptions`](../../connect/interfaces/ConnectAdapterOptions.md).[`serveShell`](../../connect/interfaces/ConnectAdapterOptions.md#serveshell) | [connect.ts:102](https://github.com/simshanith/lit-ui-router/blob/740888c2b2ba358c4dfa52a122e927df6a604b12/packages/ui-router-server/src/connect.ts#L102) |
|  `shellPath?` | (`mount`) => `string` | Maps a shell verdict's mount to the path the default [serveShell](../../connect/interfaces/ConnectAdapterOptions.md#serveshell) rewrites `req.url` to (default: the mount base itself). The hook for aliased mounts whose shell lives under another prefix. | - | [`ConnectAdapterOptions`](../../connect/interfaces/ConnectAdapterOptions.md).[`shellPath`](../../connect/interfaces/ConnectAdapterOptions.md#shellpath) | [connect.ts:92](https://github.com/simshanith/lit-ui-router/blob/740888c2b2ba358c4dfa52a122e927df6a604b12/packages/ui-router-server/src/connect.ts#L92) |
|  `shouldHandle?` | (`req`) => `boolean` | Which requests get verdicts. The default is the navigation heuristic `connect-history-api-fallback` established (and Vite's own HTML fallback mirrors): GET/HEAD requests whose Accept includes `text/html`. Module and asset fetches (`Accept: *​/*`) pass through untouched — essential under Vite, where a mount's module URLs live on the same paths as its routes. Override with `() => true` when the middleware sits behind the static layer and should judge everything. | - | [`ConnectAdapterOptions`](../../connect/interfaces/ConnectAdapterOptions.md).[`shouldHandle`](../../connect/interfaces/ConnectAdapterOptions.md#shouldhandle) | [connect.ts:131](https://github.com/simshanith/lit-ui-router/blob/740888c2b2ba358c4dfa52a122e927df6a604b12/packages/ui-router-server/src/connect.ts#L131) |