diff --git a/examples/plugins/ui-next-plugin/index.ts b/examples/plugins/ui-next-plugin/index.ts
index 10384ad314..c40ad58f11 100644
--- a/examples/plugins/ui-next-plugin/index.ts
+++ b/examples/plugins/ui-next-plugin/index.ts
@@ -1,23 +1,18 @@
 import { Context, Handler } from 'hydrooj';
 
-// Server side of the example plugin. It registers a couple of routes whose
-// handlers set a `template`; with @hydrooj/ui-next installed the `next` renderer
-// (priority 100) wins for every template, ignores the template file, and injects
-// the route/template name into the SPA shell. The client then renders the page
-// registered under `page:<template without .html>` (falling back to `page:<route name>`).
-
 class ExampleHomeHandler extends Handler {
+    useUiNext = true;
+
     async get() {
-        // Stem (`example_home`) must match the slot registered in ui/index.tsx.
-        this.response.template = 'example_home.html';
         // response.body is forwarded to the page as `args` (see usePageData).
         this.response.body = { message: 'Hello from the ui-next example plugin server side!' };
     }
 }
 
 class ExampleCssHandler extends Handler {
+    useUiNext = true;
+
     async get() {
-        this.response.template = 'example_css.html';
         this.response.body = {};
     }
 }
diff --git a/examples/plugins/ui-next-plugin/ui/index.tsx b/examples/plugins/ui-next-plugin/ui/index.tsx
index 8a92c4d5db..413dd172b0 100644
--- a/examples/plugins/ui-next-plugin/ui/index.tsx
+++ b/examples/plugins/ui-next-plugin/ui/index.tsx
@@ -1,7 +1,7 @@
 import type { PluginAPI } from '@hydrooj/ui-next';
 
 export function setup(api: PluginAPI) {
-    // (2) Page registration — slot names match the server route names / template stems
+    // (2) Page registration — slot names match the server route names
     // registered in ../index.ts. Pages are lazy-loaded on demand.
     api.registerPage('example_home', () => import('./pages/example_home'));
     api.registerPage('example_css', () => import('./pages/example_css'));
diff --git a/framework/framework/base.ts b/framework/framework/base.ts
index a70f62574c..86f866f342 100644
--- a/framework/framework/base.ts
+++ b/framework/framework/base.ts
@@ -65,8 +65,9 @@ export default (logger, xff, xhost) => async (ctx: KoaContext, next: Next) => {
             response.body ||= {};
             response.body.url = response.redirect;
         }
-        if (!response.type) {
-            if (response.pjax && args.pjax) {
+        // Attachments already have their body and content type on the Koa response.
+        if (!response.type && (!handler.useUiNext || response.body !== null || ctx.body == null)) {
+            if (!handler.useUiNext && response.pjax && args.pjax) {
                 const pjax = typeof response.pjax === 'string' ? [[response.pjax, {}]] : response.pjax;
                 response.body = {
                     fragments: (await Promise.all(
@@ -76,7 +77,7 @@ export default (logger, xff, xhost) => async (ctx: KoaContext, next: Next) => {
                 response.type = 'application/json';
             } else if (
                 request.json || response.redirect
-                || request.query.noTemplate || !response.template // no template, send raw data
+                || request.query.noTemplate || handler.useUiNext || !response.template // no template, send raw data
             ) {
                 // Send raw data
                 try {
@@ -84,7 +85,6 @@ export default (logger, xff, xhost) => async (ctx: KoaContext, next: Next) => {
                         const inject = request.headers['x-hydro-inject'].toString().toLowerCase().split(',').map((i) => i.trim());
                         if (inject.includes('pagename')) {
                             ctx.set('x-hydro-page', ctx._matchedRouteName || '');
-                            ctx.set('x-hydro-template', response.template || '');
                         }
                         if (response.body !== null && typeof response.body === 'object') {
                             if (inject.includes('uicontext')) response.body.UiContext = UiContext;
diff --git a/framework/framework/server.ts b/framework/framework/server.ts
index f168e88a24..7e2f65bdb3 100644
--- a/framework/framework/server.ts
+++ b/framework/framework/server.ts
@@ -222,6 +222,9 @@ export class HandlerCommon {
 export class Handler extends HandlerCommon {
     static [kHandler] = 'Handler';
 
+    /** Render this handler with ui-next, using its route name instead of a template. */
+    declare useUiNext?: boolean;
+
     loginMethods: any;
     notUsage = false;
     allowCors = false;
@@ -390,7 +393,7 @@ export class WebService extends Service<never> {
         ctx.mixin('server', ['Route', 'Connection', 'withHandlerClass']);
         this.server.keys = this.config.keys;
         this.server.proxy = this.config.proxy;
-        const corsAllowHeaders = 'x-requested-with, accept, origin, content-type, upgrade-insecure-requests';
+        const corsAllowHeaders = 'x-requested-with, x-hydro-inject, accept, origin, content-type, upgrade-insecure-requests';
         this.server.use(Compress());
         this.server.use(async (c, next) => {
             if ((c.request.headers.origin || c.request.headers.referer) && this.config.cors) {
diff --git a/packages/hydrooj/src/service/layers/base.ts b/packages/hydrooj/src/service/layers/base.ts
index a8edce4ead..a71a0c1697 100644
--- a/packages/hydrooj/src/service/layers/base.ts
+++ b/packages/hydrooj/src/service/layers/base.ts
@@ -12,6 +12,8 @@ export interface UiContextBase {
     cdn_dynamic: boolean;
     url_prefix: string;
     ws_prefix: string;
+    domainId?: string;
+    domainHost?: string[];
 }
 export const UiContextBase: UiContextBase = {
     cdn_prefix: '/',
@@ -34,7 +36,9 @@ export default async (ctx: KoaContext, next: Next) => {
         if (UiContext.ws_prefix.includes(',')) UiContext.ws_prefix = randomPick(UiContext.ws_prefix.split(','));
         UiContext.cdn_dynamic = system.get('server.cdn_dynamic');
     }
+    const domainHost = Array.isArray(domainInfo.host) ? domainInfo.host : [domainInfo.host];
     UiContext.domainId = domainId;
+    UiContext.domainHost = domainHost.filter(Boolean);
     UiContext.domainVersion = domain.getVersion(domainInfo);
     ctx.HydroContext.UiContext = UiContext;
     ctx.HydroContext.domain = domainInfo;
diff --git a/packages/ui-next/index.ts b/packages/ui-next/index.ts
index 40bfc72799..914739d873 100644
--- a/packages/ui-next/index.ts
+++ b/packages/ui-next/index.ts
@@ -1,9 +1,10 @@
 import fs from 'fs';
 import path from 'path';
 import esbuild from 'esbuild';
+import type { Next } from 'koa';
 import c2k from 'koa2-connect/ts';
 import { createServer, type Plugin } from 'vite';
-import { HandlerCommon, serializer } from '@hydrooj/framework';
+import { HandlerCommon, type KoaContext, serializer } from '@hydrooj/framework';
 import {
     Context, Handler, Logger,
     NotFoundError, param, SettingModel, sha1, size, Types,
@@ -169,6 +170,27 @@ class UiNextConstantHandler extends Handler {
     }
 }
 
+function getPluginBuildOptions(entries: Record<string, string>): esbuild.BuildOptions {
+    return {
+        stdin: {
+            contents: [
+                ...Object.entries(entries).map(([_, e], i) => `import * as plugin${i} from '${e}';`),
+                `window.__hydroPlugins = [${Object.entries(entries).map(([n], i) => `{ name: '${n}', ...plugin${i} }`).join(', ')}];`,
+            ].join('\n'),
+            sourcefile: 'plugins.ts',
+            resolveDir: process.cwd(),
+            loader: 'ts',
+        },
+        bundle: true,
+        format: 'esm',
+        write: false,
+        target: ['chrome90'],
+        plugins: [federationPlugin],
+        jsx: 'automatic',
+        jsxImportSource: 'react',
+    };
+}
+
 export async function buildPlugins() {
     const start = Date.now();
     let totalSize = 0;
@@ -188,38 +210,23 @@ export async function buildPlugins() {
         }
     };
 
-    if (!Object.keys(entries).length) {
-        emit('plugins.js', 'window.__hydroPlugins = [];');
-        purge();
-        logger.info('No plugins to build');
-        return;
-    }
-
     try {
+        if (!Object.keys(entries).length) {
+            emit('plugins.js', 'window.__hydroPlugins = [];');
+            purge();
+            logger.info('No plugins to build');
+            return;
+        }
+
         const result = await esbuild.build({
-            stdin: {
-                contents: [
-                    ...Object.entries(entries).map(([_, e], i) => `import * as plugin${i} from '${e}';`),
-                    `window.__hydroPlugins = [${Object.entries(entries).map(([n], i) => `{ name: '${n}', ...plugin${i} }`).join(', ')}];`,
-                ].join('\n'),
-                sourcefile: 'plugins.ts',
-                resolveDir: process.cwd(),
-                loader: 'ts',
-            },
-            bundle: true,
-            format: 'esm',
+            ...getPluginBuildOptions(entries),
             splitting: true,
             outdir: 'plugins-dist',
             entryNames: 'plugins',
             chunkNames: 'chunk-[hash]',
             assetNames: 'asset-[hash]',
             metafile: true,
-            write: false,
-            target: ['chrome90'],
-            plugins: [federationPlugin],
             minify: true,
-            jsx: 'automatic',
-            jsxImportSource: 'react',
         });
         if (result.errors.length) logger.error('Plugin build errors: %o', result.errors);
 
@@ -274,17 +281,70 @@ const injectedScripts = (resolve: (name: string) => string, viewLang: string) =>
     'versions.js',
 ].map((name) => `<script src="${resolve(name)}"></script>`);
 
+function injectPage(ctx: Context, handler: Handler, html: string, assetUrl: (name: string) => string, pluginsUrl?: string) {
+    const serialized = JSON.stringify({
+        HYDRO_INJECTED: true,
+        name: handler.context._matchedRouteName,
+        args: {
+            UserContext: handler.user,
+            UiContext: handler.UiContext,
+            ...handler.response.body,
+        },
+        url: handler.context.req.url!,
+        route_map: ctx.server.routeMap,
+        endpoint: ctx.setting.get('server.url') || undefined,
+        plugins_url: pluginsUrl,
+    }, serializer(false, handler)).replaceAll('<', '\\u003c');
+    const injectHtml = [
+        buildInject(serialized),
+        ...injectedScripts(assetUrl, getViewLang(handler)),
+    ].join('\n');
+    return html.replace(INJECT_MARKER, injectHtml);
+}
+
+const uiNextLayer = (render: (handler: Handler) => string | Promise<string>) => async (ctx: KoaContext, next: Next) => {
+    await next();
+    const handler: Handler = ctx.handler;
+    if (!handler?.useUiNext || handler.request.websocket) return;
+
+    const { request, response } = handler;
+    response.addHeader('x-hydro-ui-next', 'true');
+    if (ctx.cors) ctx.append('Access-Control-Expose-Headers', 'x-hydro-page, x-hydro-ui-next');
+    if (request.json || request.query.noTemplate || response.type || response.redirect || response.body === null) return;
+
+    response.body = await render(handler);
+    response.type = 'text/html';
+};
+
+const SupportedHandlers = [
+    'HomeHandler',
+    'ProblemMainHandler',
+];
+
 export async function apply(ctx: Context) {
     if (process.env.HYDRO_CLI) return;
 
+    for (const name of SupportedHandlers) {
+        ctx.withHandlerClass(name, (HandlerClass) => {
+            ctx.effect(() => {
+                const original = Object.getOwnPropertyDescriptor(HandlerClass.prototype, 'useUiNext');
+                HandlerClass.prototype.useUiNext = true;
+                return () => {
+                    if (original) Object.defineProperty(HandlerClass.prototype, 'useUiNext', original);
+                    else delete HandlerClass.prototype.useUiNext;
+                };
+            });
+        });
+    }
     ctx.Route('ui_next_constants', '/plugins/:version/:name', UiNextConstantHandler);
 
     if (process.env.DEV) {
-        ctx.on('app/started', async () => {
+        const buildDev = async () => {
             await buildI18n();
             await buildCodeLangs();
             await buildVersions();
-        });
+        };
+        ctx.on('app/started', buildDev);
         ctx.on('app/i18n/update', buildI18n);
         ctx.on('system/setting-loaded', buildCodeLangs);
         ctx.on('system/setting', buildCodeLangs);
@@ -311,36 +371,12 @@ export async function apply(ctx: Context) {
             ctx.server.addCaptureRoute(route, middleware);
         }
         const html = fs.readFileSync(path.join(__dirname, 'index.html'), 'utf-8');
-        ctx.server.registerRenderer('next', {
-            name: 'next',
-            accept: [],
-            output: 'html',
-            asFallback: true,
-            priority: 100,
-            async render(_name, args, context) {
-                const serialized = JSON.stringify({
-                    HYDRO_INJECTED: true,
-                    name: context.handler.context._matchedRouteName,
-                    template: context.handler.response.template || '',
-                    args: {
-                        UserContext: context.UserContext,
-                        UiContext: context.handler.UiContext,
-                        ...args,
-                    },
-                    url: context.handler.context.req.url!,
-                    route_map: ctx.server.routeMap,
-                    endpoint: ctx.setting.get('server.url') || undefined,
-                }, serializer(false, context.handler));
-                const ts = Date.now();
-                const devAssetUrl = (name: string) => `/plugins/0/${name}?_=${ts}`;
-                const injectHtml = [
-                    buildInject(serialized),
-                    ...injectedScripts(devAssetUrl, getViewLang(context.handler)),
-                ].join('\n');
-                const htmlToRender = html.replace(INJECT_MARKER, injectHtml);
-                return await vite.transformIndexHtml(context.handler.context.req.url!, htmlToRender);
-            },
-        });
+        ctx.server.addHandlerLayer('ui-next', uiNextLayer(async (handler) => {
+            const ts = Date.now();
+            const devAssetUrl = (name: string) => `/plugins/0/${name}?_=${ts}`;
+            const htmlToRender = injectPage(ctx, handler, html, devAssetUrl);
+            return vite.transformIndexHtml(handler.context.req.url!, htmlToRender);
+        }));
 
         // eslint-disable-next-line consistent-return
         return async () => {
@@ -353,45 +389,21 @@ export async function apply(ctx: Context) {
             await buildCodeLangs();
             await buildVersions();
         };
-        ctx.on('app/started', build);
-
-        ctx.server.registerRenderer('next', {
-            name: 'next',
-            accept: [],
-            output: 'html',
-            asFallback: true,
-            priority: 100,
-            async render(_name, args, context) {
-                const indexHtml = path.join(__dirname, 'public', 'index.html');
-                if (!fs.existsSync(indexHtml)) return PENDING_HTML;
-                const html = fs.readFileSync(indexHtml, 'utf-8');
-                const serialized = JSON.stringify({
-                    HYDRO_INJECTED: true,
-                    name: context.handler.context._matchedRouteName,
-                    template: context.handler.response.template || '',
-                    args: {
-                        UserContext: context.UserContext,
-                        UiContext: context.handler.UiContext,
-                        ...args,
-                    },
-                    url: context.handler.context.req.url!,
-                    route_map: ctx.server.routeMap,
-                    endpoint: ctx.setting.get('server.url') || undefined,
-                    plugins_url: `/plugins/${hashes['plugins.js'] || HASH_FALLBACK}/plugins.js`,
-                }, serializer(false, context.handler));
-                const prodAssetUrl = (name: string) => `/plugins/${hashes[name] || HASH_FALLBACK}/${name}`;
-                const injectHtml = [
-                    buildInject(serialized),
-                    ...injectedScripts(prodAssetUrl, getViewLang(context.handler)),
-                ].join('\n');
-                return html.replace(INJECT_MARKER, injectHtml);
-            },
-        });
         const debouncedBuild = ctx.debounce(build, 2000);
         const triggerHotUpdate = (filePath?: string) => {
-            if (filePath && !filePath.includes('/ui/')) return;
+            if (filePath && !filePath.includes('/ui/') && !filePath.includes('/ui-next/')) return;
             debouncedBuild();
         };
+
+        ctx.on('app/started', build);
+
+        ctx.server.addHandlerLayer('ui-next', uiNextLayer((handler) => {
+            const indexHtml = path.join(__dirname, 'public', 'index.html');
+            if (!fs.existsSync(indexHtml)) return PENDING_HTML;
+            const html = fs.readFileSync(indexHtml, 'utf-8');
+            const prodAssetUrl = (name: string) => `/plugins/${hashes[name] || HASH_FALLBACK}/${name}`;
+            return injectPage(ctx, handler, html, prodAssetUrl, prodAssetUrl('plugins.js'));
+        }));
         ctx.on('app/watch/change', triggerHotUpdate);
         ctx.on('app/watch/unlink', triggerHotUpdate);
         ctx.on('system/setting-loaded', buildCodeLangs);
diff --git a/packages/ui-next/src/app.tsx b/packages/ui-next/src/app.tsx
index 5fdb3f7dcf..ab520535d4 100644
--- a/packages/ui-next/src/app.tsx
+++ b/packages/ui-next/src/app.tsx
@@ -3,34 +3,18 @@ import DefaultLayout from './components/layout';
 import { usePageData } from './context/page-data';
 import { defineSlot } from './registry';
 import { SlotErrorBoundary } from './registry/error-boundary';
+import { resolvePage } from './registry/page';
 import { store } from './registry/store';
 
 const App = defineSlot('app:root', () => {
-  const { name, template, args } = usePageData();
+  const { name, args } = usePageData();
 
   const isError = !!(args as Record<string, unknown>).error;
 
-  const [slotName, entry] = useMemo(() => {
-    if (isError) {
-      return ['page:error', store.getDefault('page:error')] as const;
-    }
-    const templateName = typeof template === 'string' ? template.replace(/\.html$/, '') : null;
-    if (templateName) {
-      const templateSlot = `page:${templateName}` as `page:${string}`;
-      const templateEntry = store.getDefault(templateSlot);
-      if (templateEntry) {
-        if (import.meta.env.DEV) {
-          console.log(`[ui-next] using template "${templateName}" for page "${name}"`);
-        }
-        return [templateSlot, templateEntry] as const;
-      }
-    }
-    const slot = `page:${name}` as `page:${string}`;
-    if (import.meta.env.DEV) {
-      console.log(`[ui-next] using page slot "${slot}"`);
-    }
-    return [slot, store.getDefault(slot)] as const;
-  }, [name, template, isError]);
+  const [slotName, entry] = resolvePage(name, isError);
+  if (import.meta.env.DEV) {
+    console.log(`[ui-next] using page slot "${slotName}"`);
+  }
 
   const [subscribe, getSnapshot] = useMemo(() => [
     (cb: () => void) => store.subscribe(slotName, cb),
diff --git a/packages/ui-next/src/context/page-data.tsx b/packages/ui-next/src/context/page-data.tsx
index 7f358e49a8..389214096a 100644
--- a/packages/ui-next/src/context/page-data.tsx
+++ b/packages/ui-next/src/context/page-data.tsx
@@ -4,7 +4,6 @@ import { createContext, type ReactNode, useContext, useMemo, useState } from 're
 
 export interface PageData {
   name: string;
-  template: string;
   args: {
     UserContext: Record<string, any>;
     UiContext: Record<string, any>;
diff --git a/packages/ui-next/src/context/router.tsx b/packages/ui-next/src/context/router.tsx
index f8f50aa71a..c22904be9d 100644
--- a/packages/ui-next/src/context/router.tsx
+++ b/packages/ui-next/src/context/router.tsx
@@ -2,6 +2,7 @@
 
 import React, { createContext, useCallback, useContext, useEffect, useMemo, useReducer, useRef } from 'react';
 import { endpointOrigins, endpoints, isInjected, routeMapStore } from '../globals';
+import { resolvePage } from '../registry/page';
 import { useSetPageData } from './page-data';
 
 interface InternalState {
@@ -81,14 +82,25 @@ export const RouterProvider: React.FC<React.PropsWithChildren> = ({ children })
             window.location.href = res.url;
             return false;
           }
-          if (!res.ok) throw new Error(`Navigation failed: ${res.status} ${res.statusText}`);
+          if (gen !== genRef.current) return false;
+          if (res.headers.get('x-hydro-ui-next') !== 'true') {
+            window.location.assign(url);
+            return false;
+          }
           const body = await res.json();
           const pageName = res.headers.get('x-hydro-page') || '';
-          const template = res.headers.get('x-hydro-template') || '';
           console.log('[Hydro] data from', reqUrl, 'received:', body, 'pageName:', pageName);
 
           if (gen !== genRef.current) return false;
 
+          const isError = !!(body && typeof body === 'object' && body.error);
+          if (!res.ok && !isError) throw new Error(`Navigation failed: ${res.status} ${res.statusText}`);
+          const [, page] = resolvePage(pageName, isError);
+          if (!page) {
+            window.location.assign(url);
+            return false;
+          }
+
           if (init && body.routeMap && typeof body.routeMap === 'object') {
             routeMapStore.set(body.routeMap);
           }
@@ -96,7 +108,6 @@ export const RouterProvider: React.FC<React.PropsWithChildren> = ({ children })
             ...prev,
             args: body,
             name: pageName,
-            template,
             url,
           }));
           dispatch({ type: 'FETCH_SUCCESS' });
diff --git a/packages/ui-next/src/globals.ts b/packages/ui-next/src/globals.ts
index 2dc3ce4405..32161837fd 100644
--- a/packages/ui-next/src/globals.ts
+++ b/packages/ui-next/src/globals.ts
@@ -64,7 +64,6 @@ export const endpointOrigins = new Set(endpoints.map((ep) => new URL(ep).origin)
 
 export const initialPage: PageData = {
   name: (injectionData.name as string) || '',
-  template: (injectionData.template as string) || '',
   args: (injectionData.args as any) || {},
   url: (injectionData.url as string) || (window.location.pathname + window.location.search),
 };
diff --git a/packages/ui-next/src/hooks/use-build-url.ts b/packages/ui-next/src/hooks/use-build-url.ts
index 5b0ae15aad..fb502915d5 100644
--- a/packages/ui-next/src/hooks/use-build-url.ts
+++ b/packages/ui-next/src/hooks/use-build-url.ts
@@ -9,14 +9,13 @@ export interface UrlParams {
 
 export function useBuildUrl() {
   const routeMap = useRouteMap();
-  const { domainId, domain } = useUiContext();
+  const { domainId, domainHost = [] } = useUiContext();
 
   const getPrefix = useCallback((id?: string) => {
     id ||= domainId;
-    const domainHost = Array.isArray(domain.host) ? domain.host : [domain.host];
     const currentHost = window.location.host;
-    return id === (domainHost && domainHost.includes(currentHost) ? domainId : 'system') ? '' : `/d/${id}`;
-  }, [domainId, domain]);
+    return id === (domainHost.includes(currentHost) ? domainId : 'system') ? '' : `/d/${id}`;
+  }, [domainId, domainHost]);
 
   return useCallback((name: string, params: UrlParams = {}, searchParams: Record<string, string> = {}): string => {
     const pattern = routeMap[name];
diff --git a/packages/ui-next/src/pages/error.tsx b/packages/ui-next/src/pages/error.tsx
new file mode 100644
index 0000000000..3bf7489ebe
--- /dev/null
+++ b/packages/ui-next/src/pages/error.tsx
@@ -0,0 +1,6 @@
+import { usePageData } from '../context/page-data';
+
+export default function ErrorPage() {
+  const { args: { error } } = usePageData();
+  return <div role="alert">{error.message || 'Something went wrong.'}</div>;
+}
diff --git a/packages/ui-next/src/pages/index.ts b/packages/ui-next/src/pages/index.ts
index 62232fe034..280265083d 100644
--- a/packages/ui-next/src/pages/index.ts
+++ b/packages/ui-next/src/pages/index.ts
@@ -2,3 +2,4 @@ import { registerPage } from '../registry/page';
 
 registerPage('homepage', () => import('./homepage'));
 registerPage('problem_main', () => import('./problem_main'));
+registerPage('error', () => import('./error'));
diff --git a/packages/ui-next/src/pages/problem_main.tsx b/packages/ui-next/src/pages/problem_main.tsx
index 29a2c30fd3..4cd7616f18 100644
--- a/packages/ui-next/src/pages/problem_main.tsx
+++ b/packages/ui-next/src/pages/problem_main.tsx
@@ -5,6 +5,7 @@ export default function ProblemMain() {
     <div>
       <div>problem_main</div>
       <Link to="homepage">homepage</Link>
+      <Link to="problem_detail" params={{ pid: '2' }}>p2</Link>
     </div>
   );
 }
diff --git a/packages/ui-next/src/registry/page.tsx b/packages/ui-next/src/registry/page.tsx
index a67767ed0e..387ddf8b2d 100644
--- a/packages/ui-next/src/registry/page.tsx
+++ b/packages/ui-next/src/registry/page.tsx
@@ -2,6 +2,15 @@ import { lazy } from 'react';
 import { store } from './store';
 import type { PageEntry, PageLoader, PageSlotName, RegisterPageOptions } from './types';
 
+export function resolvePage(name: string, isError = false): readonly [PageSlotName, PageEntry | undefined] {
+  if (isError) {
+    return ['page:error', store.getDefault('page:error')];
+  }
+
+  const routeSlot = `page:${name}` as PageSlotName;
+  return [routeSlot, store.getDefault(routeSlot)];
+}
+
 export function registerPage<P = any>(
   name: string,
   loader: PageLoader<P>,