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

> siginfo@2.0.0 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Utility module to print pretty messages on SIGINFO/SIGUSR1

Last verified Sep 9, 2026 against siginfo@2.0.0.

siginfo ships CommonJS only. require("siginfo") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "siginfo" 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("siginfo") 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 siginfo from "siginfo"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: no types are available for siginfo; declare the module yourself if you need them.

## Facts

- Latest: 2.0.0 (Jun 16, 2020)
- Module format: CommonJS
- Last CommonJS version: 2.0.0
- TypeScript types: none
- Node engines: not declared
- Weekly downloads: 47.5M
- License: ISC

## Runtime test results for siginfo@2.0.0

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

| Runtime | require("siginfo") | import "siginfo" |
|---|---|---|
| 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 siginfo

ES modules:

```js
import siginfo from "siginfo";
```

CommonJS:

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

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (4 versions; the newest 4 shown).

| Versions | Format | First published |
|---|---|---|
| 1.0.0 – 2.0.0 | CommonJS | Oct 3, 2017 |

## Frequently asked

**Is siginfo ESM-only?**

siginfo@2.0.0 is a CommonJS package. siginfo ships CommonJS only. require("siginfo") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "siginfo" 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 siginfo with ES module syntax?**

Yes. import siginfo from "siginfo" 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 siginfo work in Bun?**

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

**Does siginfo ship TypeScript types?**

No. siginfo ships no type declarations and there is no @types package for it.

## Links

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

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