bun-types/docs/guides/runtime/typescript.mdx

Type definitions and documentation for Bun, an incredibly fast JavaScript runtime

---
title: Install TypeScript declarations for Bun
sidebarTitle: TypeScript types
mode: center
---

To install TypeScript definitions for Bun's built-in APIs in your project, install `@types/bun`.

```sh terminal icon="terminal"
bun add -d @types/bun # dev dependency
```

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Below is the full set of recommended `compilerOptions` for a Bun project. With this `tsconfig.json`, you can use top-level await, extensioned or extensionless imports, and JSX.

```json tsconfig.json icon="file-json"
{
  "compilerOptions": {
    // Environment setup & latest features
    "lib": ["ESNext"],
    "target": "ESNext",
    "module": "Preserve",
    "moduleDetection": "force",
    "jsx": "react-jsx",
    "allowJs": true,

    // Bundler mode
    "moduleResolution": "bundler",
    "allowImportingTsExtensions": true,
    "verbatimModuleSyntax": true,
    "noEmit": true,

    // Best practices
    "strict": true,
    "skipLibCheck": true,
    "noFallthroughCasesInSwitch": true,
    "noUncheckedIndexedAccess": true,
    "noImplicitOverride": true,

    // Some stricter flags (disabled by default)
    "noUnusedLocals": false,
    "noUnusedParameters": false,
    "noPropertyAccessFromIndexSignature": false
  }
}
```

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Refer to [Ecosystem > TypeScript](/docs/runtime/typescript) for a complete guide to TypeScript support in Bun.