📋 multi-db-event-logger

A flexible, database-agnostic event logger for Node.js with MongoDB and PostgreSQL support, AES-256-GCM encryption, and a clean TypeScript-first API.

✨ Features

• 🗄️ MongoDB and PostgreSQL support — plug in your URL, done.
• 🔐 AES-256-GCM authenticated encryption for sensitive event payloads.
• 📦 Dynamic collections/tables — each eventType gets its own collection/table, or use a single master_event_logs.
• 📄 Paginated queries with flexible data-field filtering.
• 🟦 TypeScript-first with full type exports.
• ⚡ Dual CJS + ESM build — works in both require() and import environments.
• 🪶 Zero bloat — no ORM, no framework lock-in.

📦 Installation

npm install multi-db-event-logger

Then install the driver for your database:

# MongoDB
npm install mongodb

# PostgreSQL
npm install pg

⚙️ Quick Start

MongoDB

import { EventLogger } from 'multi-db-event-logger';

const logger = new EventLogger({
  type: 'mongodb',
  url: 'mongodb://localhost:27017/mydb',
});

await logger.connect();

// Log a plain event
await logger.addEvent({
  eventType: 'user',
  eventName: 'user_login',
  data: { userId: '123', ip: '192.168.1.1', browser: 'Chrome' },
  isOwn: true, // stored in `user_event_logs` collection
});

// Log an encrypted event
await logger.addEvent({
  eventType: 'payment',
  eventName: 'card_charged',
  data: { userId: '123', amount: 99.99, card: '4111111111111111' },
  encryption: true,
  isOwn: true,
});

await logger.disconnect();

PostgreSQL

import { EventLogger } from 'multi-db-event-logger';

const logger = new EventLogger({
  type: 'postgres',
  url: 'postgres://user:pass@localhost:5432/mydb',
  encryptionKey: 'your-32-byte-secret-key-goes-here', // optional
});

await logger.connect();

await logger.addEvent({
  eventType: 'order',
  eventName: 'order_placed',
  data: { orderId: 'ORD-001', total: 250.00, items: 3 },
  isOwn: true, // stored in `order_event_logs` table
});

await logger.disconnect();

Note: Tables are created automatically on first use. No migrations needed.

🔌 Connecting

const logger = new EventLogger({ type: 'mongodb', url: '...' });

// connect() is idempotent — safe to call multiple times
await logger.connect();

// Always disconnect when shutting down
process.on('SIGTERM', () => logger.disconnect());

📝 addEvent(params)

Logs a new event to the database.

| Parameter | Type | Required | Default | Description | |-------------|-----------|----------|---------|-------------| | eventType | string | ✅ yes | — | Event category (e.g. "user", "payment") | | eventName | string | ✅ yes | — | Specific event (e.g. "user_login") | | data | object | ✅ yes | — | JSON payload | | encryption | boolean | ❌ no | false | Encrypt data with AES-256-GCM | | isOwn | boolean | ❌ no | false | true → {eventType}_event_logs, false → master_event_logs |

const result = await logger.addEvent({
  eventType: 'user',
  eventName: 'profile_updated',
  data: { userId: '123', fields: ['email', 'avatar'] },
});

if (result.success) {
  console.log(result.data); // StoredEvent
} else {
  console.error(result.error);
}

🔍 getEvents(params)

Retrieves events with filtering and pagination.

| Parameter | Type | Required | Default | Description | |---------------|-----------|----------|---------|-------------| | eventType | string | ✅ yes | — | Category to query | | eventName | string | ✅ yes | — | Event name to query | | filter | object | ❌ no | {} | Filter on data fields, e.g. { userId: '123' } | | isFromMaster | boolean | ❌ no | false | Query master_event_logs instead of own table | | isEncrypted | boolean | ❌ no | — | true = encrypted only (auto-decrypted), false = plain only | | page | number | ❌ no | 1 | Page number | | limit | number | ❌ no | 10 | Records per page |

// Fetch all user login events (page 1, 20 per page)
const result = await logger.getEvents({
  eventType: 'user',
  eventName: 'user_login',
  filter: { userId: '123' }, // filter on data.userId
  page: 1,
  limit: 20,
});

console.log(`Found ${result.total} events across ${result.totalPages} pages`);
console.log(result.data); // StoredEvent[]

// Fetch encrypted payment events (auto-decrypted)
const payments = await logger.getEvents({
  eventType: 'payment',
  eventName: 'card_charged',
  isEncrypted: true,
});

🔐 Encryption

Encryption uses AES-256-GCM (authenticated encryption). Set a 32-byte key:

// Option 1: Pass in config
const logger = new EventLogger({
  type: 'postgres',
  url: '...',
  encryptionKey: 'your-32-byte-secret-key-here!!!!',
});

// Option 2: Environment variable
// ENCRYPTION_KEY=your-32-byte-secret-key-here!!!!

Important: The key is padded/truncated to exactly 32 bytes. Use a randomly generated key and never commit it to version control.

🗄️ Storage Behaviour

MongoDB

| isOwn | Collection | |---------|------------| | true | {eventType}_event_logs | | false | master_event_logs |

PostgreSQL

Tables are auto-created with this schema:

CREATE TABLE IF NOT EXISTS "{eventType}_event_logs" (
  id           SERIAL      PRIMARY KEY,
  event_type   VARCHAR(255) NOT NULL,
  event_name   VARCHAR(255) NOT NULL,
  data         JSONB        NOT NULL,
  is_encrypted BOOLEAN      NOT NULL DEFAULT FALSE,
  is_own       BOOLEAN      NOT NULL DEFAULT FALSE,
  created_at   TIMESTAMPTZ  NOT NULL DEFAULT NOW()
);

Indexes are created automatically on (event_type, event_name) and (created_at DESC).

📐 TypeScript Types

import type {
  EventLoggerConfig,
  AddEventParams,
  AddEventResult,
  GetEventsParams,
  GetEventsResult,
  StoredEvent,
} from 'multi-db-event-logger';

📜 License

MIT © Jigar Suthar