Practice & Assessment
Test your understanding of API Routes and Server Actions
Multiple Choice Questions
5You define both page.tsx and route.ts in the same folder. What happens?
Where should 'use server' be placed to mark a Server Action?
What does revalidatePath('/blog') do when called inside a Server Action?
Using Zod in a Server Action, what does safeParse return when validation fails?
In a Route Handler for /api/posts/[id], how do you access the id param?
Coding Challenges
1Build a CRUD REST API for a Notes App
Create Route Handlers for a notes API using an in-memory array as the data store (no database needed). Implement: GET /api/notes (returns all notes as JSON array), POST /api/notes (accepts { title, body } JSON body, adds to array, returns created note with generated id, status 201), GET /api/notes/[id] (returns single note or 404), DELETE /api/notes/[id] (removes note, returns 204). Use Zod to validate the POST body — title must be a non-empty string, body must be at least 5 characters. Return field-level errors as { errors: { title: string[], body: string[] } } on validation failure with status 400. Test with curl or a REST client. Time estimate: 25-30 minutes.
Mini Project
Full-Stack Contact Form with Admin Dashboard
Build a contact form application using Server Actions and Route Handlers. Requirements: public /contact page with a form (name, email, message fields); Server Action createContact that validates input with Zod (name min 2 chars, valid email format, message min 20 chars) and stores to an in-memory store (or JSON file); use useActionState to show validation errors per field and a success state; GET /api/contacts Route Handler returning all submissions as JSON with an x-total-count header; /admin/contacts Server Component that fetches from the Route Handler and displays all submissions in a table; middleware that protects /admin routes by checking for an admin-secret cookie (redirect to /login if missing); a /login page with a form action that sets the cookie. All mutations use Server Actions. All data display uses Server Components.