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

> tap@21.8.0 ships CommonJS and ESM builds. Dual package — require() works on every Node.js version we test; import works too.

A Test-Anything-Protocol library for JavaScript

Last verified Sep 9, 2026 against tap@21.8.0.

tap publishes both a CommonJS entry and a native ESM entry (ESM added in 15.0.0). require("tap") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js 20 || >=22. import "tap" works alongside it.

## What to do

1. Nothing to change. require("tap") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js 20 || >=22. import * as tap from "tap" works alongside it; use named imports for what the ESM entry exports.
2. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 21.8.0 (Sep 3, 2026)
- Module format: Dual (CommonJS + ESM)
- Last CommonJS version: 21.8.0
- Native ESM since: 15.0.0
- TypeScript types: bundled
- Node engines: 20 || >=22
- Weekly downloads: 312K
- License: BlueOak-1.0.0

## Runtime test results for tap@21.8.0

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

| Runtime | require("tap") | import "tap" |
|---|---|---|
| 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 | fails (ERR_NOT_IMPLEMENTED) | fails (ERR_NOT_IMPLEMENTED) |

## How to import tap

ES modules:

```js
import * as tap from "tap";
```

Namespace import shown because the ESM entry may have no default export; use named imports for what it exports.

CommonJS:

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

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (368 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 18.4.4 – 21.8.0 | Dual (CommonJS + ESM) | Oct 8, 2023 |

## Frequently asked

**Is tap ESM-only?**

tap@21.8.0 ships CommonJS and ESM builds. tap publishes both a CommonJS entry and a native ESM entry (ESM added in 15.0.0). require("tap") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js 20 || >=22. import "tap" works alongside it.

**Can I require tap?**

Yes. tap ships a CommonJS entry alongside the native ESM entry. require("tap") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js 20 || >=22.

**Does tap work in Bun?**

Importing tap failed in Bun 1.4.0 on Sep 9, 2026: NotImplementedError: node:v8 Serializer is not yet implemented in Bun.

**Does tap ship TypeScript types?**

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

## Links

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

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