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

> inflight@1.0.6 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Add callbacks to requests in flight to avoid async duplication

Last verified Sep 9, 2026 against inflight@1.0.6.

inflight ships CommonJS only. require("inflight") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "inflight" 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.

**Deprecated:** This module is not supported, and leaks memory. Do not use it. Check out lru-cache if you want a good and tested way to coalesce async requests by a key value, which is much more comprehensive and powerful.

## What to do

1. require("inflight") 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 inflight from "inflight"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: npm install -D @types/inflight
4. This package is deprecated: This module is not supported, and leaks memory. Do not use it. Check out lru-cache if you want a good and tested way to coalesce async requests by a key value, which is much more comprehensive and powerful.

## Facts

- Latest: 1.0.6 (Oct 13, 2016)
- Module format: CommonJS
- Last CommonJS version: 1.0.6
- TypeScript types: @types/inflight
- Node engines: not declared
- Weekly downloads: 83.4M
- License: ISC

## Runtime test results for inflight@1.0.6

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

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

ES modules:

```js
import inflight from "inflight";
```

CommonJS:

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

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (7 versions; the newest 7 shown).

| Versions | Format | First published |
|---|---|---|
| 1.0.0 – 1.0.6 | CommonJS | May 5, 2014 |

## Frequently asked

**Is inflight ESM-only?**

inflight@1.0.6 is a CommonJS package. inflight ships CommonJS only. require("inflight") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "inflight" 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 inflight with ES module syntax?**

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

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

**Does inflight ship TypeScript types?**

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

## Links

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

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