Awesome

jiti

Just-in-Time Typescript and ESM support for Node.js.

[!IMPORTANT] This is the development branch for jiti v2. Check out jiti/v1 for latest stable docs and unjs/jiti#174 for the v2 roadmap.

✅ Features

Seamless Typescript and ESM syntax support
Seamless interoperability between ESM and CommonJS
Synchronous API to replace require()
Asynchronous API to replace import()
ESM Loader support
Super slim and zero dependency
Smart syntax detection to avoid extra transforms
Node.js native require cache integration
Filesystem transpile with hard disk caches
Custom resolve aliases

🌟 Used by

💡 Usage

CLI

You can use jiti CLI to quickly run any script with Typescript and native ESM support!

npx jiti ./index.ts

# or

jiti ./index.ts

Programmatic

// --- Initialize ---

// ESM
import { createJiti } from "jiti";
const jiti = createJiti(import.meta.url);

// CommonJS
const { createJiti } = require("jiti");
const jiti = createJiti(__filename);

// --- ESM Compatible APIs ---

// jiti.import() acts like import() with Typescript support
await jiti.import("./path/to/file.ts");

// jiti.esmResolve() acts like import.meta.resolve() with additional features
const resolvedPath = jiti.esmResolve("./src");

// --- CJS Compatible APIs ---

// jiti() acts like require() with Typescript and (non async) ESM support
jiti("./path/to/file.ts");

// jiti.resolve() acts like require.resolve() with additional features
const resolvedPath = jiti.resolve("./src");

You can also pass options as second argument:

const jiti = createJiti(import.meta.url, { debug: true });

Register global ESM loader

You can globally register jiti using global hooks.

Note: This is an experimental approach and only tested to work on Node.js > 20. I don't recommend it and unless you have to, please prefer explicit method.

import "jiti/register";

Or:

node --import jiti/register index.ts

⚙️ Options

`debug`

Type: Boolean
Default: false
Environment variable: JITI_DEBUG

Enable verbose logging. You can use JITI_DEBUG=1 <your command> to enable it.

`fsCache`

Type: Boolean | String
Default: true
Environment variable: JITI_FS_CACHE

Filesystem source cache (enabled by default)

By default (when is true), jiti uses node_modules/.cache/jiti (if exists) or {TMP_DIR}/jiti.

Note: It is recommended to keep this option enabled for better performance.

`moduleCache`

Type: String
Default: true
Environment variable: JITI_MODULE_CACHE

Runtime module cache (enabled by default).

Disabling allows editing code and importing same module multiple times.

When enabled, jiti integrates with Node.js native CommonJS cache store.

`transform`

Type: Function
Default: Babel (lazy loaded)

Transform function. See src/babel for more details

`sourceMaps`

Type: Boolean
Default false
Environment variable: JITI_SOURCE_MAPS

Add inline source map to transformed source for better debugging.

`interopDefault`

Type: Boolean
Default: false
Environment variable: JITI_INTEROP_DEFAULT

Return the .default export of a module at the top-level.

`alias`

Type: Object
Default: -
Environment variable: JITI_ALIAS

Custom alias map used to resolve ids.

`nativeModules`

Type: Array
Default: ['typescript`]
Environment variable: JITI_NATIVE_MODULES

List of modules (within node_modules) to always use native require for them.

`transformModules`

Type: Array
Default: []
Environment variable: JITI_TRANSFORM_MODULES

List of modules (within node_modules) to transform them regardless of syntax.

`experimentalBun`

Type: Boolean
Default: Enabled if process.versions.bun exists (Bun runtime)
Environment variable: JITI_EXPERIMENTAL_BUN

Enable experimental native Bun support for transformations.

Development

Clone this repository
Enable Corepack using corepack enable
Install dependencies using pnpm install
Run pnpm dev
Run pnpm jiti ./test/path/to/file.ts

License

Published under the MIT license. Made by @pi0 and community 💛 <br><br> <a href="https://github.com/unjs/jiti/graphs/contributors"> <img src="https://contrib.rocks/image?repo=unjs/jiti" /> </a>