Protected Route Groups & App Layout Organize authenticated application routes without changing public URLs
Phase 20 - Production Application UI Volume 06 - Professional Frontend
(app) route group
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Phase 20 turns the secure full-stack foundation into a coherent, accessible application interface without moving business authority into the browser.
Route groups let us organize without changing URLs The App Router can group authenticated application routes under `(app)` while keeping clean URLs such as `/tasks` and `/projects`. The protected layout becomes the natural place to verify the Supabase session and render the shared shell.
src/app/ ■■■ layout.tsx ■■■ signin/ ■■■ auth/ ■■■ (app)/ ■■■ layout.tsx ■■■ dashboard/page.tsx ■■■ projects/page.tsx ■■■ tasks/ ■ ■■■ page.tsx ■ ■■■ loading.tsx ■ ■■■ error.tsx ■ ■■■ not-found.tsx ■■■ account/page.tsx
Protected layout
export default async function AppLayout({ children }) {
const supabase = await createClient()
const { data, error } = await supabase.auth.getClaims()if (error || !data?.claims?.sub) redirect('/signin')
return <AppShell user={...}>{children}</AppShell> }
A user could call NestJS without rendering this layout. Phase 18/19 guards and authorization remain mandatory.
Shared layout should remain stable The shell should survive navigation so users keep orientation. Route content changes inside `` while navigation and account context stay visually consistent.
Next.js is useful only when you can explain what runs on the server, what crosses into the browser, and which route owns a user-visible state.
Restate the goal of “Protected Route Groups and App Layout” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: route → Server Component → client boundary → request/data source → rendered UI. Mark the one boundary this lesson changes.
Inspect the current repository state and record the exact files, route, table, or runtime involved. Avoid creating an abstraction before you can name the existing owner.
Implement the smallest vertical slice. Add one coherent change, run the narrowest verification command, and read the output before continuing.
Connect the slice to TaskFlow’s phase artifact: TaskFlow responsive shell with navigation, workspace context, task screens, loading/empty/error states, and accessible interactions.. Verify behavior from the outside as a user or API client would.
Create one controlled failure that is safe to reproduce. Predict the symptom first, capture evidence, locate the earliest broken boundary, then fix only that cause.
Close the reference and rebuild or explain the core change from memory. Record what you would monitor or test before trusting the same change in production.
// app/tasks/page.tsx
import { TaskList } from "./task-list";
export default async function TasksPage() {
const tasks = await loadTasks();
return <TaskList initialTasks={tasks} />;
}Do not copy this as a finished answer. Predict what each boundary does, type the smallest useful slice, run it, then compare the result with your prediction.
Locate the first browser-only API or stateful hook and move the client boundary to the smallest component that needs it.
Verify route params, fetch location, cache behavior, and the exact server response before changing JSX.
Without copying the final source, create a second small scenario that applies “Protected Route Groups and App Layout” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Create reusable primitives for page header, panel/card, empty state, loading skeleton, and error state.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.Global client component wrapping the whole app
Predict the symptom before causing the failure. Then locate the earliest boundary where reality diverges from expectation.Why does this responsibility live here, what input does it trust, what output proves success, and what would go wrong if another layer owned it?
If your explanation is vague, repeat the boundary trace before moving on.Close the reference. Reproduce the core idea from memory or explain the exact request/data flow aloud. Then check your diff or notes for accidental shortcuts that bypass validation, authorization, error handling, or verification earned in earlier phases.