What is tsx?

tsx stands for TypeScript Execute, and it's a simple command to run TypeScript in Node.js.

Because tsx is basically an alias to node, you can use it the same way:

node file.js

→↓

tsx file.js

_{Since it's Node.js underneath, all command-line flags are supported. Use tsx as you would use node!}

Features

No hassle TypeScript runner

• Just run TypeScript code. No configuration required!

  The primary goal of tsx is to run TypeScript code with modern and sensible defaults. This makes tsx very user-friendly and great for beginners!

CJS ↔ ESM interop

• Seamlessly cross-import CommonJS and ES Modules!

  If you've encountered the following error in Node, you'll never see it again with tsx!

  Error [ERR_REQUIRE_ESM]: require() of ES Module <ESM package> from ./file.js not supported.
  Instead change the require of <ESM package> in ./file.js to a dynamic import() which is available in all CommonJS modules.

  _{This happens in Node.js when importing an ESM file from CommonJS, which can happen in new dependencies.}

Watch mode

• Iterate on your code faster and boost productivity!

  As a DX bonus, tsx comes with a watcher to re-run your files whenever you save them.

Limitations

TypeScript & ESM transformations are handled by esbuild, so it shares some of the same limitations such as:

• Compatibility with eval() is not preserved
• Only certain tsconfig.json properties are supported
  • emitDecoratorMetadata is not supported

For details, see esbuild's JavaScript caveats and TypeScript caveats documentation.