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

> event-stream@4.0.1 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

construct pipes of streams of events

Last verified Sep 9, 2026 against event-stream@4.0.1.

event-stream ships CommonJS only. require("event-stream") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "event-stream" 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("event-stream") 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 eventStream from "event-stream"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: npm install -D @types/event-stream

## Facts

- Latest: 4.0.1 (Sep 29, 2018)
- Module format: CommonJS
- Last CommonJS version: 4.0.1
- TypeScript types: @types/event-stream
- Node engines: not declared
- Weekly downloads: 5.6M
- License: MIT

## Runtime test results for event-stream@4.0.1

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

| Runtime | require("event-stream") | import "event-stream" |
|---|---|---|
| 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 event-stream

ES modules:

```js
import eventStream from "event-stream";
```

CommonJS:

```js
const eventStream = require("event-stream");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (84 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 1.1.0 – 4.0.1 | CommonJS | May 21, 2012 |

## Frequently asked

**Is event-stream ESM-only?**

event-stream@4.0.1 is a CommonJS package. event-stream ships CommonJS only. require("event-stream") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "event-stream" 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 event-stream with ES module syntax?**

Yes. import eventStream from "event-stream" 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 event-stream work in Bun?**

Yes. import "event-stream" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does event-stream ship TypeScript types?**

Not bundled. Install the community types with "npm install -D @types/event-stream".

## Links

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

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