用户账户与登录
添加注册和身份验证功能
用户账户与登录 是 CoddyKit 上的免费 Vibe Coding 课时。 这是第 4 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Vibe Coding 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Vibe Coding 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Who Is Using Your App?
Your app stores data, but right now everyone shares the same data. A real product needs to know who each person is so each freelancer sees only their own clients and hours. That's what authentication (login) gives you.
Two related ideas: authentication answers "who are you?" and authorization answers "what are you allowed to do?" In this lesson you'll add both to your full-stack app with AI's help.
Don't Build Auth From Scratch
Authentication is security-critical and easy to get dangerously wrong. The pro move — even for experienced developers — is to use a trusted auth library or service rather than rolling your own.
Popular, AI-friendly options include Clerk, Supabase Auth, Auth0 and NextAuth/Auth.js. Let AI recommend one for your stack.
I'm adding login to my Next.js freelancer hours app. I do NOT want to build authentication from scratch.
Recommend ONE beginner-friendly auth solution (e.g. Clerk, Supabase Auth, or Auth.js). For your pick, explain:
- why it's safe and easy
- what sign-in methods it supports (email, Google, etc.)
- one sentence on how it fits Next.jsHow Login Actually Works
The basic flow: a user enters credentials (or signs in with Google), the auth service verifies them and issues a session — a token that proves who they are on every later request.
Your app checks that session to decide what to show. You don't store raw passwords yourself; the auth service handles the scary parts.
Explain how the login flow works in plain language for my app, using the auth tool you recommended.
Walk through: user signs up, signs in, gets a session, and how my app uses that session on later requests to know who they are. Mention why I never store raw passwords myself.Add Sign-Up and Sign-In Screens
Start with the visible part: pages where users can create an account and log in. Modern auth libraries provide ready-made components, so this is often just a few lines.
Ask AI to add the sign-up/sign-in UI and wire it into your app's navigation.
Set up sign-up and sign-in for my Next.js app using the auth tool we chose.
- add the sign-in and sign-up pages/components
- support email/password and Google sign-in
- add a 'Sign out' button in the header when logged in
Show me each file to create or edit and any environment variables I need. Keep secrets out of the code.Protect Your Pages and Endpoints
A logged-out visitor shouldn't reach the dashboard or hit your data endpoints. Protecting routes means checking for a valid session and redirecting or rejecting if it's missing.
Ask AI to guard both your frontend pages and your API endpoints — both halves need protection, not just the screen.
Protect my app so only logged-in users can use it.
- redirect logged-out users away from the dashboard page to the sign-in page
- on the API side, reject requests to /api/entries that have no valid session, returning a 401
Show me the middleware or guards needed and explain why protecting the API matters even if the page is already protected.A Tiny Session Check
At its core, route protection is a simple check: is there a valid session? Here's the idea in plain JavaScript — a guard that decides whether to allow or block a request. Run it to see both cases.
function handleRequest(session) {
if (!session || !session.userId) {
return { status: 401, body: "Please sign in" };
}
return { status: 200, body: "Welcome, user " + session.userId };
}
console.log(handleRequest(null));
console.log(handleRequest({ userId: 42 }));Tie Data to the Logged-In User
Now the key step: each time entry must belong to a user, so people see only their own data. That means adding a userId to your records and filtering every query by the current user.
Ask AI to update your schema and endpoints so data is scoped to whoever is logged in.
Make my data per-user. Each TimeEntry and Client should belong to the logged-in user.
- add a userId field tied to the authenticated user
- when creating an entry, attach the current user's id
- when listing entries, only return rows belonging to the current user
Update the Prisma schema and the /api/entries endpoints. Give me the migration command too.Authorization: Who Can Do What
Being logged in isn't enough — you must ensure a user can only touch their own records. Without this, anyone could edit someone else's entry by guessing an id. That's an authorization check, and it's a common AI blind spot.
Explicitly ask AI to verify ownership on update and delete.
Add ownership checks to my update and delete endpoints.
Before updating or deleting a TimeEntry, confirm it belongs to the currently logged-in user. If it belongs to someone else, return 403 Forbidden — never modify it.
Show the updated PUT and DELETE routes and explain why checking the session alone is not enough.Show the User They're Logged In
Good apps make auth feel friendly: show the user's name or avatar, a clear "Sign out" button, and helpful states for loading and errors. This polish builds trust.
Ask AI to surface the logged-in user's info and handle the in-between states gracefully.
Polish the auth experience in my app.
- show the logged-in user's name and avatar in the header
- add a clean 'Sign out' action
- show a loading state while the session is being checked, so the UI doesn't flicker
- if sign-in fails, show a friendly message
Show me the component changes and keep the styling minimal.Test the Whole Auth Flow
Before calling it done, walk the full journey: sign up, sign out, sign back in, add data, then sign in as a different user and confirm you see none of the first user's data. That proves both authentication and authorization work.
If something leaks across users, describe the exact steps to AI — it's a precise way to find the gap.
Help me test my app's auth end to end. Give me a step-by-step test checklist that includes:
- sign up, sign out, sign back in
- adding data as User A
- signing in as User B and confirming User B canNOT see User A's data
- trying to edit User A's entry while signed in as User B (should be blocked)
Tell me what correct behavior looks like at each step.A Complete Full-Stack App
You did it: a frontend, a backend, a real database, and now secure user accounts — a genuinely full-stack app, built almost entirely by talking to AI. Each freelancer signs in and sees only their own clients and hours.
This is the foundation real products are built on. From here you can deploy it, add payments, or grow features — all with the same vibe-coding workflow you've practiced.
Quick Check
Lock in the security mindset.
Recap: Accounts and Login
You secured your full-stack app:
- Authentication identifies the user; authorization controls what they can do
- Use a trusted auth service (Clerk, Supabase Auth, Auth.js) — never roll your own
- Protect both pages and API endpoints with session checks
- Scope data per user with a userId and filter every query
- Verify ownership before update/delete, and test across multiple users
Congratulations — you've built a complete full-stack app by talking to AI. Next courses cover deploying, payments and shipping it to real users!
用 AI 导师学习 JavaScript — 免费
在浏览器中编写并运行真实代码，获得全天候 AI 导师的即时帮助，并在网页或应用中继续学习。
- 课程
- 25
- 课程
- 100
常见问题解答
「用户账户与登录」课时是免费的吗？
是的 — 「用户账户与登录」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Vibe Coding 课程的其余内容，请升级到 CoddyKit PRO。 Vibe Coding 课程共包含 4 节课。
「用户账户与登录」这节课中我会学到什么？
添加注册和身份验证功能 你通过在浏览器中直接运行的动手代码来练习 Vibe Coding，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Vibe Coding 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Vibe Coding 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 4 节课，共 4 节。
「用户账户与登录」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Vibe Coding 课中编写并运行代码吗？
能。每节 Vibe Coding 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。
此课程中的所有课时
- 使用人工智能规划应用
- 前端与后端协同
- 添加数据库
- 用户账户与登录