This chapter walks through installing the TypeScript compiler, creating a project, and configuring your editor.

Install TypeScript

You need Node.js installed. Then install TypeScript globally or per project:

  # Global (convenient for learning)
npm install -g typescript

# Verify
tsc --version   # e.g. Version 5.x.x

For real projects, prefer a local dev dependency so everyone uses the same version:

  mkdir my-ts-app && cd my-ts-app
npm init -y
npm install --save-dev typescript
npx tsc --version

Your First TypeScript File

Create src/index.ts:

  const username: string = 'Alice';
const score: number = 95;

function celebrate(name: string, points: number): string {
    return `${name} scored ${points} points!`;
}

console.log(celebrate(username, score));

Compile and run:

  npx tsc
node dist/index.js

By default, tsc emits JavaScript next to the source file. We will redirect output with tsconfig.json.

tsconfig.json

Initialize a config file:

  npx tsc --init

A practical starter configuration:

  {
  "compilerOptions": {
    "target": "ES2020",
    "module": "ESNext",
    "moduleResolution": "bundler",
    "outDir": "./dist",
    "rootDir": "./src",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "dist"]
}
Option Purpose
target JavaScript version emitted by the compiler
module Module system for output (CommonJS, ESNext, etc.)
outDir / rootDir Separate source and compiled output
strict Enable all strict type-checking options

Compile with:

  npx tsc

Add npm scripts in package.json:

  {
  "scripts": {
    "build": "tsc",
    "watch": "tsc --watch"
  }
}

tsc --watch recompiles automatically when you save files.

VS Code Setup

  1. Install Visual Studio Code
  2. Install the official TypeScript and JavaScript Language Features extension (built-in)
  3. Open your project folder — VS Code uses the workspace typescript version from node_modules when present

Useful shortcuts:

  • Hover over a variable to see its inferred type
  • Cmd/Ctrl + Click to jump to definitions
  • Problems panel lists type errors without running tsc

VS Code can compile on save. Add to .vscode/settings.json:

  {
  "typescript.tsdk": "node_modules/typescript/lib",
  "editor.formatOnSave": true
}

Project Layout 

  my-ts-app/
├── src/
│   └── index.ts
├── dist/              (generated)
├── tsconfig.json
├── package.json
└── node_modules/

Running TypeScript Directly (Optional)

For quick scripts without a build step, use tsx or ts-node:

  npm install --save-dev tsx
npx tsx src/index.ts

These compile and execute in one step — handy during development. Production builds use tsc or a bundler like Vite.