Akshay Kolhapure

Posted on Feb 9

I Built an Open-Source Authentication Engine for Node.js (with the Help of AI)

#ai #opensource #backend #node

Authentication is one of those things that looks simple until you try to run it in production.

JWT-based authentication is everywhere in the Node.js ecosystem, but after working on multiple real-world backend systems, I kept facing the same recurring issue:

JWT libraries are excellent at creating and verifying tokens —
but they stop short when it comes to session management.

Production systems need much more than stateless tokens.

They need:

Session awareness
Refresh token rotation
Token revocation (“logout all devices”)
Device & IP tracking
Rate limiting against brute-force attacks
Extensibility for future security needs

That gap is what led me to build Smart Auth Engine.

🔐 What Is Smart Auth Engine?

Smart Auth Engine is an open-source authentication engine for Node.js and TypeScript, built on top of JWT but designed with stateful session intelligence.

📦 npm: https://www.npmjs.com/package/smart-auth-engine
💻 GitHub: https://github.com/kolhapureakshay/smart-auth-engine

Instead of treating authentication as “just token generation”, it treats auth as backend infrastructure.

🧠 The Core Idea: JWT + Session Intelligence

JWTs are powerful, but on their own they are:

Stateless
Hard to revoke
Blind to device and session context

Smart Auth Engine layers session tracking on top of JWT, enabling:

Multiple sessions per user
Secure refresh token rotation
Immediate session revocation
Device & IP visibility
Safer long-lived authentication

This approach gives you the scalability of JWT with the control of session-based auth.

✨ Key Features

Smart Auth Engine currently provides:

✅ Stateful session management on top of JWT
🔁 Refresh token rotation with replay-attack detection
🧠 Session intelligence (device + IP tracking)
🔐 Role-Based Access Control (RBAC) middleware
🚦 Rate limiting utilities for login protection
🔌 Pluggable storage adapters (In-memory, Redis)
🧩 Modular architecture with event bus & plugins
💙 TypeScript-first API with strong typings

All features are fully open-source and self-hostable.

🏗️ Why I Built This Instead of Using Existing Libraries

Most existing Node.js authentication libraries focus on:

Token creation
Token verification

But real backend systems need:

Session lifecycle control
Safer refresh token handling
Clean extensibility
Framework-agnostic design

I wanted:

Something I’d trust in production
A clean foundation for future security features (MFA, OAuth)
A modular system that grows with the application

Smart Auth Engine is the result of that mindset.

🤖 How AI Helped During Development

While building Smart Auth Engine, I used AI tools to:

Explore and validate architectural approaches
Review security patterns and edge cases
Improve documentation clarity
Speed up repetitive development tasks

AI didn’t replace engineering judgment —
it amplified productivity and design thinking.

The final decisions around security, architecture, and API design were always deliberate and manual.

🧠 Open-Source First Philosophy

Smart Auth Engine follows an open-core, developer-first philosophy:

✔ All core authentication features are open-source
✔ No artificial feature locking
✔ Fully transparent and self-hostable
✔ Designed for extensibility and long-term growth

If commercial offerings ever exist, they would focus on hosted services and tooling, not core authentication logic.

Developer trust matters.

⚠️ Project Status

Smart Auth Engine is currently at v0.1.0.

That means:

APIs may evolve
Feedback is highly encouraged
Real-world usage will shape future releases

The goal right now is learning and validation, not hype.

🛣️ What’s Coming Next

Some planned directions:

Fastify and NestJS adapters
OAuth / social login support
Multi-factor authentication (MFA)
Additional storage adapters
More real-world examples

🙌 Feedback Welcome

If you:

Build Node.js backends
Work with JWT, authentication, or session management
Care about secure and scalable auth design

I’d love your feedback:

Does this solve a real problem for you?
What would you expect from an auth engine?
What should come next?

🔗 Links