esno

4.8.0 verified Mon Apr 27 auth: no javascript

A Node.js runtime enhanced with esbuild for loading TypeScript and ESM modules. Version 4.8.0 is current and stable, with frequent releases alongside tsx. esno is essentially an alias of tsx (formerly esno was separate, now merged into tsx package). Differentiator: auto CJS/ESM mode detection, seamless TypeScript execution without config, and caching for faster reloads. Suitable for scripts, CLIs, and development servers.

Common errors

error ERR_MODULE_NOT_FOUND: Cannot find module 'esno' imported from ↓

cause Using esno as a programmatic import but it's a CLI-only package.

fix

Use 'tsx' package: import 'tsx' or use npx tsx.

error TypeError: esno is not a function ↓

cause Importing esno as a function, but the default export is a no-op.

fix

Use tsx for programmatic usage: import 'tsx'.

error Error: Cannot find module 'esno/register' ↓

cause The register path was removed; esno delegates to tsx.

fix

Use node -r tsx/register script.ts instead.

error Warning: esno is deprecated; use tsx instead. ↓

cause esno is now an alias of tsx.

fix

Switch to tsx: npm uninstall -g esno && npm install -g tsx

Warnings

breaking From v0.15, esno is an alias of tsx; all issues must be reported in esbuild-kit/tsx. ↓

fix Use tsx package instead for new projects or if you need programmatic API.

deprecated The 'esno' package itself is deprecated in favor of 'tsx'. ↓

fix Migrate to 'tsx' for future updates and support.

gotcha esno does not provide a programmatic API; importing it is a no-op. ↓

fix Use 'tsx' package for transform or register hooks in code.

gotcha If using require('esno'), it will not register the TypeScript loader; use -r esno/register. ↓

fix Use node -r esno/register script.ts instead of programmatic require.

Install

npm install esno

yarn add esno

pnpm add esno

Imports

default
wrong
```
const esno = require('esno')
```
correct
```
import esno from 'esno'
```
esno provides a CLI only, not a programmatic API. The default import is a no-op function; use tsx for programmatic usage.
tsx
wrong
```
import 'esno'
```
correct
```
import 'tsx'
```
For programmatic transform, import 'tsx' directly (esno delegates to tsx).
require('esno')
wrong
```
require('esno')
```
correct
```
node -r esno/register script.ts
```
esno's register hook is not a CommonJS module; use the -r flag.

Quickstart

Run a TypeScript file directly using esno, which transpiles with esbuild and executes with Node.js.

npx esno hello.ts