Installation

CatalystEngine is distributed as an npm package with both CommonJS and ESM builds, and includes TypeScript type declarations.

Requirements

• Node.js ≥ 18
• TypeScript ≥ 5 (recommended, but not required: the engine also works in plain JavaScript)

Adding it to your project

npm

npm install catalyst-engine

pnpm

pnpm add catalyst-engine

yarn

yarn add catalyst-engine

Import

The entire public API is exposed from the package entry point:

import {
  CatalystEngine,
  StatManager,
  ExperienceManager,
  SkillManager,
  EngineEventBus,
  ModifierType,
} from 'catalyst-engine';

All types and interfaces are exported as well — see Interfaces and types.

Building from source

If you're working on the repository instead of the published package:

npm install
npm run build   # generates dist/ in CJS + ESM format with type declarations
npm run dev     # watch mode (recompiles on every change)

The build is handled by tsup.

Tests

The suite uses Vitest and covers 100% of the codebase (statements, branches, functions and lines). The thresholds are enforced in vitest.config.ts: a coverage regression makes the build fail.

npm test               # runs the suite once
npm run test:watch     # watch mode
npm run test:coverage  # coverage report