# Is @protobufjs/codegen ESM-only? Can you require() it?

> @protobufjs/codegen@2.0.5 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

A minimalistic code generation utility.

Last verified Sep 9, 2026 against @protobufjs/codegen@2.0.5.

@protobufjs/codegen ships CommonJS only. require("@protobufjs/codegen") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "@protobufjs/codegen" 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("@protobufjs/codegen") 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 codegen from "@protobufjs/codegen"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 2.0.5 (Apr 27, 2026)
- Module format: CommonJS
- Last CommonJS version: 2.0.5
- TypeScript types: bundled
- Node engines: not declared
- Weekly downloads: 49.8M
- License: BSD-3-Clause

## Runtime test results for @protobufjs/codegen@2.0.5

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

| Runtime | require("@protobufjs/codegen") | import "@protobufjs/codegen" |
|---|---|---|
| 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 @protobufjs/codegen

ES modules:

```js
import codegen from "@protobufjs/codegen";
```

CommonJS:

```js
const codegen = require("@protobufjs/codegen");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (15 versions; the newest 15 shown).

| Versions | Format | First published |
|---|---|---|
| 1.0.0 – 2.0.5 | CommonJS | Dec 11, 2016 |

## Frequently asked

**Is @protobufjs/codegen ESM-only?**

@protobufjs/codegen@2.0.5 is a CommonJS package. @protobufjs/codegen ships CommonJS only. require("@protobufjs/codegen") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "@protobufjs/codegen" 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 @protobufjs/codegen with ES module syntax?**

Yes. import codegen from "@protobufjs/codegen" 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 @protobufjs/codegen work in Bun?**

Yes. import "@protobufjs/codegen" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does @protobufjs/codegen ship TypeScript types?**

Yes. @protobufjs/codegen bundles its own type declarations; no @types package is needed.

## Links

- [@protobufjs/codegen on npm](https://www.npmjs.com/package/@protobufjs/codegen)
- [Source repository](https://github.com/dcodeIO/protobuf.js)
- [HTML version](https://canirequire.com/package/@protobufjs/codegen/)
- [JSON version](https://canirequire.com/package/@protobufjs/codegen.json)

---

For scripts and AI agents: any package is at https://canirequire.com/package/<name>/index.md (Markdown) or https://canirequire.com/package/<name>.json (JSON); the site index is https://canirequire.com/llms.txt. Fetch the URL directly; no search needed.