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Only CommonJS mode

Node.js runs files in CommonJS mode when the file extension is .cjs (or .cts if TypeScript), or .js when package.json#type is undefined or set to commonjs.

This section is only for adding tsx in CommonJS mode (doesn't affect .mjs or .mts files, or .js files when package.js#type is set to module).

Not for 3rd-party packages

This enhances the entire runtime so it may not be suitable for loading TypeScript files from a 3rd-party package as it may lead to unexpected behavior in user code.

For importing TypeScript files in CommonJS mode without affecting the environment, see tsx.require().

Command-line API

Pass tsx into the --require flag:

node --require tsx/cjs ./file.ts

NODE_OPTIONS environment variable

NODE_OPTIONS='--require tsx/cjs' npx some-binary

Programmatic API

Load tsx/cjs at the top of your entry-file:


// Now you can load TS files

Registration & Unregistration

To manually register and unregister the tsx enhancement:

const tsx = require('tsx/cjs/api')

// Register tsx enhancement
const unregister = tsx.register()

// Unregister when needed