fix: await io

AGENTS.md

@@ -25,6 +25,8 @@
 prefer `useServerAction` (`@/lib/client/util`) or (if `useServerAction` doesn't work) `useActionState`
 over manually storing response/error state with `useState`.
 - To call Server Functions on mount (e.g. to fetch data), use SWR.
+- RSCs must call `await io()` before accessing server state (`getConfig`, `getAuth`, etc),
+  unless they have already used a request-time API (`cookies`, `params`, etc).
 
 # Error handling
 

src/app/admin/components/AccessControl.tsx

@@ -1,10 +1,13 @@
+import { io } from 'next/cache'
+
 import { getConfig } from '@/lib/server/config'
 import { getDb } from '@/lib/server/db'
 
 import { AllowlistEditor } from './AllowlistEditor'
 import { RegistrationModeControl } from './RegistrationModeControl'
 
 export async function AccessControl() {
+  await io()
   const mode = getConfig().registrationMode
   const allowed =
     mode === 'restricted' ? await getDb().allowedGithubUser.findMany({ orderBy: { githubUsername: 'asc' } }) : []

src/app/admin/components/UserManagement.tsx

@@ -1,11 +1,15 @@
+import { io } from 'next/cache'
+
 import { requireAdmin } from '@/app/admin/actions'
 import { getDb } from '@/lib/server/db'
 
 import { UserRow } from './UserRow'
 
 export async function UserManagement() {
+  await io()
+  const db = getDb()
   const [users, session] = await Promise.all([
-    getDb().user.findMany({
+    db.user.findMany({
       select: { id: true, name: true, isAdmin: true },
       orderBy: { createdAt: 'asc' },
     }),

src/app/layout.tsx

@@ -1,10 +1,10 @@
 import '@/css/app.css'
 
 import type { Metadata } from 'next'
+import { io } from 'next/cache'
 import { Open_Sans } from 'next/font/google'
 import Image from 'next/image'
 import Link from 'next/link'
-import { connection } from 'next/server'
 import { type ReactNode, Suspense } from 'react'
 
 import { ConfigCtx } from '@/lib/contexts'
@@ -30,7 +30,8 @@ export default async function RootLayout({
 }: Readonly<{
   children: ReactNode
 }>) {
-  // https://nextjs.org/docs/app/getting-started/caching#opting-out-of-the-static-shell
+  // FIXME: this is currently the only `Suspense` in the app,
+  // so we don't get static shells for any page.
   return (
     <Suspense fallback={null}>
       <RootLayoutBody>{children}</RootLayoutBody>
@@ -43,11 +44,10 @@ async function RootLayoutBody({
 }: Readonly<{
   children: ReactNode
 }>) {
-  // NOTE: together with the Suspense above, this makes the entire app dynamic:
-  // nothing is pre-rendered and every request recomputes its output HTML.
-  // This means we don't have to worry about cache invalidation,
-  // but will need fixing if it becomes a perf issue.
-  await connection()
+  // NOTE: Awaiting `io` makes the root layout dynamic
+  // (every request recomputes its output HTML),
+  // though static shells for pages may still be pre-rendered by `next build`.
+  await io()
 
   const serverCfg = getConfig()
   const clientCfg = {

src/lib/server/auth.ts

@@ -4,6 +4,7 @@ import { betterAuth, type SocialProviders } from 'better-auth'
 import { prismaAdapter } from 'better-auth/adapters/prisma'
 import { nextCookies } from 'better-auth/next-js'
 import crypto from 'crypto'
+import { io } from 'next/cache'
 import { headers } from 'next/headers'
 import { unauthorized } from 'next/navigation'
 
@@ -134,6 +135,7 @@ export async function getAuth(): Promise<AuthInstance> {
 
 /** Require an authenticated user. Throws `unauthorized()` if not logged in. */
 export async function requireAuth(): Promise<SessionAndUser> {
+  await io()
   const auth = await getAuth()
   const session = await auth.api.getSession({ headers: await headers() })
   if (!session) unauthorized()

src/lib/server/config.ts

@@ -164,9 +164,7 @@ function ensureConfigWatcher() {
 
 /** Return the server configuration.
  *
- * The object may be mutated. `saveConfig()` must be called after any modifications.
- *
- * Use {@link CacheTag.serverConfig} in Server Components that read this. */
+ * The object may be mutated. `saveConfig()` must be called after any modifications. */
 export function getConfig(): ServerConfig {
   if (!g.__config) initConfig()
   return g.__config!