How to Add Login to Your Cursor AI App (Without Firebase or Auth0)

Keywords: authentication for AI apps, firebase alternative, auth for vibe-coded apps, login for codegen apps

You’ve shipped something fast. Now what?

You’ve built a killer MVP using Cursor, Windsurf, or another AI/codegen tool. The frontend’s done. The logic’s running. But now you need to let users log in — and suddenly you’re staring down Firebase dashboards, Auth0 docs, and security questions you weren’t expecting.

It’s a familiar pattern: vibe-code the product, hit a wall at authentication, and start duct-taping.

Let’s talk about a better way — and why your AI-generated app deserves real, programmable authentication that works with your tools, your stack, and your workflow.

Why Firebase and Auth0 Break Momentum

Firebase and Auth0 are the usual suspects. But here’s what they don’t tell you until it’s too late:

• Firebase is fast — until you need anything custom. Want to add a new login method? Change flows per user group? Suddenly you're writing Cloud Functions and managing vendor-specific rules.

• Auth0 looks enterprise-ready — but the complexity and cost stack up fast. And customizing flows becomes a labyrinth of JSON configs and visual editors.

For early-stage apps, these tools feel like buying a spaceship when all you need is a bike. But rolling your own? That’s a security headache you don’t want.

Prefactor: Authentication That Works With Codegen

Prefactor takes a different approach: we treat authentication as code. You define your login flows in a domain-specific language (DSL) — and deploy them like infrastructure.

It’s not config. It’s not locked behind a UI. It’s programmable, composable, and version-controlled — which means you can vibe-code your Prefactor setup in Cursor, Windsurf, or any AI coding environment you’re already using.

✨ Yes — you can use Cursor to build your Prefactor auth flow. Because it’s all code.

How to Add Login in Under 10 Minutes

Let’s say you’ve built a frontend in Cursor and now want to add login via email and password.

Here’s how it works with Prefactor:

1. Define your auth flow in the DSL

2. Deploy it via the Prefactor CLI

3. Use the SDK to wire it into your frontend — returns secure tokens, handles sessions, and manages the auth state

4. Ship

Want to add magic links? Social login? Entra ID SSO? Extend the DSL, redeploy, done.

Why This Works Better for Vibe-Coded Apps

Your stack moves fast. Your auth layer should too.

• You don’t want to be blocked by inflexible third-party dashboards

• You want auth flows you can manage, test, and version in Git

• You want to define login logic in the same way you define app logic

Prefactor gives you developer-first infrastructure for authentication — without slowing down your AI-coded workflow.

TL;DR

🚫 Stop copy-pasting login flows
🚫 Stop configuring auth in a dashboard you hate
✅ Start defining authentication in code — and vibe-code it with Cursor or Windsurf if that’s your thing

Ready to Try It?

Get your first flow running in minutes. Use your CLI. Use Cursor. Use Windsurf. It’s just code.

👉 Start building with Prefactor now