Install TS-Rex in your TypeScript project today

TS-Rex is published to npm as @fajarnugraha37/ts-rex. Install with npm, pnpm, yarn, or bun. Requires TypeScript 5.0 or higher for type inference.

TS-Rex is published to the npm registry as @fajarnugraha37/ts-rex. You can install it with any Node.js-compatible package manager. The package ships prebuilt ESM and CJS bundles alongside TypeScript declaration files, so no additional build configuration is required.

Install the package

Choose your package manager and run the corresponding command:

npm

npm install @fajarnugraha37/ts-rex

pnpm

pnpm add @fajarnugraha37/ts-rex

yarn

yarn add @fajarnugraha37/ts-rex

bun

bun add @fajarnugraha37/ts-rex

TypeScript requirement

TS-Rex uses advanced generic type inference features introduced in TypeScript 5.0. The phantom type state tracking and compile-time capture inference rely on these features and will not work correctly with earlier versions.

[!WARNING] TypeScript 5.0 or higher is required. If your project uses an older version, upgrade TypeScript before installing TS-Rex.

You can check your current TypeScript version with:

npx tsc --version

TS-Rex declares TypeScript as a peer dependency in package.json:

{
  "peerDependencies": {
    "typescript": "^5"
  }
}

Module formats

The package ships three output formats from the dist/ directory, so it works in any modern JavaScript environment without extra configuration:

File	Format	Use case
dist/index.mjs	ESM	Node.js with "type": "module", bundlers (Vite, esbuild, Rollup)
dist/index.cjs	CJS	Node.js CommonJS, older bundlers
dist/index.d.ts	Type declarations	TypeScript type checking in all environments

The package.json exports field maps these automatically based on your environment:

{
  "exports": {
    ".": {
      "types": "./dist/index.d.ts",
      "import": "./dist/index.mjs",
      "require": "./dist/index.cjs"
    }
  }
}

Import the library

Once installed, import the rx factory function to start building patterns. This is the only named export you need for most use cases:

import { rx } from '@fajarnugraha37/ts-rex';

If you need to reference the builder or result types explicitly in your own type signatures, you can import them alongside rx:

import { rx, RegexBuilder, CompiledRegex, MatchResult } from '@fajarnugraha37/ts-rex';

Zero runtime dependencies

TS-Rex has no runtime dependencies. The devDependencies in package.json include build tools (tsup, tsx), testing utilities (expect-type), and linting (eslint, typescript-eslint) — none of which are bundled into the distributed package.

[!NOTE] Because TS-Rex depends only on native TypeScript and RegExp, adding it to your project does not increase your production bundle size beyond the library itself.

Next steps

• Quickstart: Build your first type-safe regex pattern in under five minutes.
• Core concepts: Understand the AST engine, immutability, and phantom type state.