Audit Log System (NestJS + Prisma + PostgreSQL)

Overview

This project implements an audit logging system using NestJS, Prisma, and PostgreSQL.
It automatically records user/system actions (CREATE, UPDATE, DELETE, GET) with metadata such as IP address, device info, and location.
The goal is to provide accountability and traceability for application events.

Features

• NestJS Interceptor for automatic logging of requests
• Prisma ORM with PostgreSQL for structured storage
• Captures:
  • Action type (CREATE, UPDATE, DELETE, GET)
  • Entity and entity ID
  • Before and after state
  • IP address
  • Device info
  • Location (via GeoIP lookup)
  • Timestamp

Installation

npm i @ochoche/audit-log

Setup Instructions

1. Add the AuditLog model to your Prisma schema

model AuditLog {
  id          String   @id @default(uuid())
  action      String
  entity      String
  entityId    String?
  beforeState Json?
  afterState  Json?
  ipAddress   String?
  deviceInfo  String?
  location    String?
  timestamp   DateTime @default(now())
}

Run migrations:

npx prisma migrate dev --name add_audit_log
npx prisma generate

2. Configure environment variables

Create a .env file with your database connection:

DATABASE_URL="postgresql://user:password@localhost:5432/auditlogdb"
npm install

3. Import the module

In your app.module.ts:

import { Module } from '@nestjs/common';
import { AuditLogModule } from '@ochoche/audit-log';

@Module({
  imports: [AuditLogModule],
})
export class AppModule {}

4. Apply the interceptor globally

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { AuditLogInterceptor } from '@ochoche/audit-log';
import { AuditlogService } from '@ochoche/audit-log';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  const auditLogService = app.get(AuditlogService);
  app.useGlobalInterceptors(new AuditLogInterceptor(auditLogService));
  await app.listen(process.env.PORT ?? 3000);
}
bootstrap();

Usage

You can also inject the service directly for manual logging:

import { AuditLogService } from '@ochoche/audit-log';

@Injectable()
export class OrdersService {
  constructor(private readonly auditLogService: AuditLogService) {}

  async updateOrder(orderId: string, data: any) {
    // ... update logic
    await this.auditLogService.createLog({
      action: 'UPDATE',
      entity: 'Order',
      entityId: orderId,
      beforeState: { /* old data */ },
      afterState: { /* new data */ },
      ipAddress: '127.0.0.1',
      deviceInfo: 'Mozilla/5.0',
      location: 'Nigeria',
    });
  }
}

Author

Ochoche