Package Exports

@kylegillen/nestjs-fastify-better-auth
@kylegillen/nestjs-fastify-better-auth/dist/index.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@kylegillen/nestjs-fastify-better-auth) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

NestJS Fastify Better Auth Integration

A comprehensive NestJS with Fastify integration library for Better Auth, providing seamless authentication and authorization for your NestJS applications.

# Using npm
npm install @kylegillen/nestjs-fastify-better-auth

# Using yarn
yarn add @kylegillen/nestjs-fastify-better-auth

# Using pnpm
pnpm add @kylegillen/nestjs-fastify-better-auth

# Using bun
bun add @kylegillen/nestjs-fastify-better-auth

Prerequisites

Before you start, make sure you have:

A working NestJS application
Better Auth installed and configured (installation guide)

Usage

Import the AuthModule in your root module:

import { Module } from '@nestjs/common'
import { AuthModule } from '@kylegillen/nestjs-fastify-better-auth'
import { auth } from './auth'

@Module({
  imports: [
    AuthModule.forRoot({
      auth: auth
    }),
  ],
})
export class AppModule {}

Below is a valid configuration for asynchronous registration of the module.

import { Module } from '@nestjs/common'
import { AuthModule } from '@kylegillen/nestjs-fastify-better-auth'
import { auth } from './auth'

@Module({
  imports: [
    AuthModule.forRootAsync({
      useFactory: () => {
        return auth
      }
      imports: [],
      inject: []
    }),
  ],
})
export class AppModule {}

Route Protection

Better Auth provides an AuthGuard to protect your routes. You can choose one of two approaches to implement route protection:

Option 1: Controller or Route Level Protection

Apply the guard to specific controllers or routes:

import { Controller, Get, UseGuards } from '@nestjs/common';
import { AuthGuard, Optional, Public } from '@thallesp/nestjs-better-auth';

@Controller('users')
@UseGuards(AuthGuard) // Apply to all routes in this controller
export class UserController {
  @Get('me')
  async getProfile() {
    return { message: "Protected route" };
  }

  @Optional()
  @Get('optional')
  async getOptional() {
    return { message: "Optional route" };
  }

  @Public()
  @Get('public')
  async getPublic() {
    return { message: "Public route" };
  }
}

Option 2: Global Protection

Alternatively, you can register the guard globally using APP_GUARD to protect all routes by default:

import { Module } from '@nestjs/common';
import { APP_GUARD } from '@nestjs/core';
import { AuthModule, AuthGuard } from '@thallesp/nestjs-better-auth';
import { auth } from "./auth";

@Module({
  imports: [
    AuthModule.forRoot(auth),
  ],
  providers: [
    {
      provide: APP_GUARD,
      useClass: AuthGuard,
    },
  ],
})
export class AppModule {}

[!NOTE]
Choose either the controller/route level approach or the global approach based on your needs. You don't need to implement both.

Decorators

Better Auth provides several decorators to enhance your authentication setup:

Session Decorator

Access the user session in your controllers:

import { Controller, Get } from '@nestjs/common';
import { Session, UserSession } from '@thallesp/nestjs-better-auth';

@Controller('users')
export class UserController {
  @Get('me')
  async getProfile(@Session() session: UserSession) {
    return session;
  }
}

Public and Optional Decorators

Control authentication requirements for specific routes:

import { Controller, Get } from '@nestjs/common';
import { Public, Optional } from '@thallesp/nestjs-better-auth';

@Controller('users')
export class UserController {
  @Get('public')
  @Public() // Mark this route as public (no authentication required)
  async publicRoute() {
    return { message: "This route is public" };
  }

  @Get('optional')
  @Optional() // Authentication is optional for this route
  async optionalRoute(@Session() session: UserSession) {
    return { authenticated: !!session, session };
  }
}

Alternatively, use it as a class decorator to specify access for an entire controller:

import { Controller, Get } from '@nestjs/common';
import { Public, Optional } from '@thallesp/nestjs-better-auth';

@Public() // All routes inside this controller are public
@Controller('public')
export class PublicController { /* */ }

@Optional() // Authentication is optional for all routes inside this controller
@Controller('optional')
export class OptionalController { /* */ }