🛡️ NestShield

Real-time API monitoring for NestJS. No database. No extra setup. Just install and go.

Live Demo →

What does it do?

Once installed, NestShield automatically:

• 📊 Shows a live dashboard at /nestshield/ui
• 🚦 Rate limits requests per IP
• 🔒 Blocks IPs that exceed the rate limit
• 📧 Sends you an email when something goes wrong

No Redis. No database. No Prometheus. No Grafana. Nothing extra.

Installation

npm install nestshield

Setup — 3 steps

Step 1 — Add to your AppModule

Open your app.module.ts and add NestShield:

import { Module } from '@nestjs/common';
import { NestShieldModule } from 'nestshield';

@Module({
  imports: [
    NestShieldModule.forRoot({
      alerts: {
        email: 'you@youremail.com', // ← your email, alerts will be sent here
      },
    }),
  ],
})
export class AppModule {}

That's the minimum config. Just your email address.

Step 2 — Start your server

npm run start:dev

Step 3 — Open the dashboard

http://localhost:3000/nestshield/ui

You're done. ✅

What you'll see on startup

✅ NestShield alerts ready → sending to you@youremail.com
🕐 NestShield alert checker started (every 30s)

This means everything is working correctly.

Email Alerts

NestShield monitors your API every 30 seconds and sends you an email when:

You don't need to set up any email account. NestShield sends alerts from its own email directly to your inbox.

💡 Check your spam folder the first time — some email clients flag new senders.

Full Configuration

All options are optional except email:

NestShieldModule.forRoot({

  // Rate limiting settings
  throttle: {
    ttl:   60000,  // time window in milliseconds (default: 60000 = 1 minute)
    limit: 100,    // max requests per IP per window (default: 100)
  },

  // Alert settings
  alerts: {
    email: 'you@youremail.com',  // required — where to send alerts

    errorRateThreshold: 5,       // alert when error % goes above this (default: 5)
    latencyThreshold:   1000,    // alert when p95 ms goes above this (default: 1000)
    cooldownMs:         600000,  // wait this long before sending same alert again
                                 // default: 600000 = 10 minutes
  },

})

Dashboard Overview

Visit http://localhost:3000/nestshield/ui to see:

Built-in API Endpoints

Important Notes

Metrics reset on restart — Everything is stored in memory, so metrics clear when your server restarts. This is intentional — it keeps NestShield zero-infrastructure. If you want long-term history, call /nestshield/stats periodically and save the data yourself.

Multiple instances — If you run multiple server instances (e.g. horizontal scaling), each instance tracks its own metrics independently.

Comparison

Contributing

git clone https://github.com/prranavyo/nestshield.git
cd nestshield
npm install
npm run start:dev

Please open an issue before submitting a PR.

License

MIT © Pranav Karanam

Built for the NestJS community
Live Demo