# Is arg ESM-only? Can you require() it?

> arg@5.0.2 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Unopinionated, no-frills CLI argument parser

Last verified Sep 9, 2026 against arg@5.0.2.

arg ships CommonJS only. require("arg") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "arg" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

## What to do

1. require("arg") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun.
2. From ES modules use the default import: import arg from "arg"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 5.0.2 (Jun 5, 2022)
- Module format: CommonJS
- Last CommonJS version: 5.0.2
- TypeScript types: bundled
- Node engines: not declared
- Weekly downloads: 71.2M
- License: MIT

## Runtime test results for arg@5.0.2

Installed and executed on Sep 9, 2026 with require("arg") from a CommonJS file and import "arg" from an ES module.

| Runtime | require("arg") | import "arg" |
|---|---|---|
| Node.js 18 | works | works |
| Node.js 20 | works | works |
| Node.js 22 | works | works |
| Node.js 24 | works | works |
| Node.js 26 | works | works |
| Bun 1.4.0 | works | works |

## How to import arg

ES modules:

```js
import arg from "arg";
```

CommonJS:

```js
const arg = require("arg");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (14 versions; the newest 14 shown).

| Versions | Format | First published |
|---|---|---|
| 0.0.1 – 5.0.2 | CommonJS | Jun 1, 2012 |

## Frequently asked

**Is arg ESM-only?**

arg@5.0.2 is a CommonJS package. arg ships CommonJS only. require("arg") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "arg" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

**Can I import arg with ES module syntax?**

Yes. import arg from "arg" works in Node.js and Bun because they support importing CommonJS modules. Named imports work only when Node.js can statically detect the exports.

**Does arg work in Bun?**

Yes. import "arg" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does arg ship TypeScript types?**

Yes. arg bundles its own type declarations; no @types package is needed.

## Links

- [arg on npm](https://www.npmjs.com/package/arg)
- [Source repository](https://github.com/vercel/arg)
- [HTML version](https://canirequire.com/package/arg/)
- [JSON version](https://canirequire.com/package/arg.json)

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