Getting Started

Prerequisite: Chronicle Kernel

You need a running Chronicle Kernel before connecting with the TypeScript client.

The easiest local setup is the development Docker image:

docker run -p 35000:35000 cratis/chronicle:latest-development

Installation

yarn add @cratis/chronicle reflect-metadata

Note: reflect-metadata is required for TypeScript decorators to work at runtime. Import it once at the entry point of your application.

Setup

Import reflect-metadata at the top of your application entry point:

import 'reflect-metadata';

Connecting to Chronicle

Create a ChronicleClient with a connection string pointing to your Chronicle Kernel instance:

import { ChronicleClient, ChronicleOptions } from '@cratis/chronicle';

const options = ChronicleOptions.fromConnectionString('chronicle://localhost:35000');
const client = new ChronicleClient(options);

// Get an event store
const store = await client.getEventStore('MyStore');

// ... use the store

// Always dispose when done
client.dispose();

Connection String Format

Chronicle connection strings use the chronicle:// scheme:

chronicle://localhost:35000
chronicle://username:password@chronicle.example.com:35000

Development Mode

For local development, use:

const options = ChronicleOptions.development();

This connects to chronicle://localhost:35000 by default.

Where to next

• Events and event logs, Event Types, and Event Evolution to model and evolve your event schema.
• Reducers, Reactors, and Projections to build read models and side effects from your events.
• Read Models to query projected state.
• Event Seeding and Transactions for test data and unit-of-work semantics.
• Compliance for PII handling and GDPR erasure.