@markwylde/eventbase v1.3.3

Eventbase

A distributed event-sourced database built on NATS JetStream and LevelDB.

Features

• Event sourcing architecture
• Distributed state management
• Real-time data synchronization
• Simple key-value storage API
• Automatic event replay and state reconstruction

Installation

npm install @markwylde/eventbase

Prerequisites

• NATS Server with JetStream enabled running on your network
• Node.js 20 or higher

Quick Start

import createEventbase from '@markwylde/eventbase';

// Initialize eventbase
const eventbase = await createEventbase({
  streamName: 'mytodoapp',
  nats: {
    servers: ["localhost:4222", "localhost:4223"]
  }
});

// Store data
await eventbase.put('user123', { name: 'John Doe' });

// Retrieve data
const user = await eventbase.get('user123');
console.log(user); // { name: 'John Doe' }

// Delete data
await eventbase.delete('user123');

// Close connection
await eventbase.close();

API

createEventbase(config)

Creates a new Eventbase instance.

Config Options:

• streamName: Name of the NATS stream to use
• servers: Array of NATS server addresses

Methods

subscribe(filter: string, callback: function)

Returns an array of keys that match the given filter.

const unsubscribe = eventbase.subscribe('user:*', (key, data) => {
  console.log(`User ${key} updated:`, data);
});
unsubscribe();

keys(filter: string)

Returns an array of keys that match the given filter.

await eventbase.put('user456', { name: 'Jane Smith' });

put(id: string, data: any)

Stores data with the given ID.

await eventbase.put('user123', { name: 'John Doe' });

get(id: string)

Retrieves data for the given ID. Returns null if not found.

const user = await eventbase.get('user123');
console.log(user); // { name: 'John Doe' }

delete(id: string)

Deletes data with the given ID.

await eventbase.delete('user123');

close()

Closes all connections and cleans up resources.

await eventbase.close();

Storage

Data is stored in both:

• LevelDB (local state)
• NATS JetStream (distributed event log)

The local state is automatically rebuilt from the event log on startup.

Development

# Start a local nats cluster
docker compose up -d

# Install dependencies
npm install

# Run the demo
npm start

# Run with auto-reload
npm run dev