nest-auth-guard

A reusable NestJS Auth guard for validating JWT tokens locally or trusting API Gateway headers in production. This guard automatically switches behavior based on the NODE_ENV environment variable.

📦 Features

• ✅ Auth JWT validation when running locally
• ✅ API Gateway passthrough validation in production (via trusted headers)
• ✅ Works with Bearer tokens
• ✅ Lightweight and configurable
• ✅ Built for microservice environments

🚀 Installation

1. Install the package

npm install nest-auth-guard

2. Install required peer dependencies

npm install @nestjs/common @nestjs/core @nestjs/passport passport passport-jwt ioredis

🔐 Required Environment Variables

| Key | Example Value | Required | Description | | ---------------- | ----------------------- | -------- | ------------------------------------- | --- | | NODE_ENV | local or production | ✅ | Used to switch between local and prod | | | REDIS_HOST | localhost | ✅ | Redis host (defaults to localhost) | | REDIS_PORT | 6379 | ✅ | Redis port (defaults to 6379) | | REDIS_PASSWORD | your-password | ❌ | Redis password (optional) | | REDIS_DB | 0 | ✅ | Redis database index (defaults to 0) | | REDIS_USERNAME | your-username | ❌ | Redis username (optional) |

Add these in your .env file:

NODE_ENV=local
REDIS_HOST=localhost
REDIS_PORT=6379
REDIS_PASSWORD=your-password  # Optional
REDIS_DB=0  # Optional: database index
REDIS_USERNAME=your-username # Optional

🔁 In production, you can set NODE_ENV=production and pass user info via x-user header.

🧪 Usage in a NestJS Service

1. Enable .env loading

In app.module.ts of your NestJS service:

import { ConfigModule } from "@nestjs/config";

@Module({
  imports: [ConfigModule.forRoot({ isGlobal: true })],
})
export class AppModule {}

2. Protect a route using the guard

import { Controller, Get, Req, UseGuards } from "@nestjs/common";
import { AuthGuard } from "nest-auth0-guard";

@Controller("profile")
@UseGuards(AuthGuard)
export class ProfileController {
  @Get()
  getProfile(@Req() req) {
    return req.user; // decoded token or forwarded user info
  }
}

🛡 How It Works

| NODE_ENV | Behavior | | ------------ | ------------------------------------------ | | local | Validates JWT from Authorization: Bearer | | production | Reads user from x-user header |

Redis Integration

The guard automatically fetches additional user data from Redis using the user.userId field as the key. If Redis data is found, it merges with the authenticated user object. The Redis key format is user:{user.userId}.

Example Redis data structure:

{
  "user:68fb768c7f86363f4140899c": {
    "preferences": { "theme": "dark" },
    "profile": { "avatar": "https://example.com/avatar.jpg" },
    "settings": { "notifications": true }
  }
}