Package.json with multiple entrypoints

Stack Overflow Asked by Jeanluca Scaljeri on July 29, 2020

I have a library which was used as follows

import { Foo } from '@me/core';
const foo = new Foo();

The package.json of that library looks like

"name": "@me/core",
"version": "1.0.0",
"main": "dist/index.js",
"types": "dist/index.d.ts",
"license": "MIT",

With dist/index.js its entrypoint. Now, however, I would provide an import for NodeJs projects only and one for web projects. Ideally I would have something like this for NodeJs

import { Foo } from '@me/core/nodejs';

and if you’re working on a web-project you could do

import { Foo } from '@me/core/web';

My understanding is that both @me/core/nodejs and @me/core/web will be different NPM packages this way, which is not what I want. I want it to be in 1 npm package.

I tried to changed the library’s index.ts file, from

export * from './foo';


import * as nodejs from './nodejs';
import * as web from './web';

export { web, nodejs };

This actually works, but I have to use it now (in a NODEJS project) as follows

import { nodejs } from '@me/core';

const foo = new nodejs.Foo();

Is there maybe a way to import this such that I don’t need the nodejs everytime?

As you can see I’m not so sure what I should do here so any help would be appreciated!

UPDATE: Based on the suggestions by @Klaycon I see the following error:

enter image description here

One Answer

As you're using ECMAScript modules, please refer to node.js docs on package entry points:

In a package’s package.json file, two fields can define entry points for a package: "main" and "exports". The "main" field is supported in all versions of Node.js, but its capabilities are limited: it only defines the main entry point of the package.
The "exports" field provides an alternative to "main" where the package main entry point can be defined while also encapsulating the package, preventing any other entry points besides those defined in "exports". This encapsulation allows module authors to define a public interface for their package.

So, in your package.json, you could define exports like this:

  "main": "dist/index.js",
  "exports": {
    ".": "dist/index.js",
    "./nodejs": "dist/nodejs",
    "./web": "dist/web",

Correct answer by Klaycon on July 29, 2020

Add your own answers!

Related Questions

Get all tables where there is no booking on this time or date

2  Asked on November 24, 2021 by tierno


How to remove first view pager item in kotlin?

1  Asked on November 24, 2021 by marlen-schreiner


Pandas update values using loc with repeated indices

2  Asked on November 24, 2021 by tyler-klein


ORDER BY with priority

2  Asked on November 22, 2021 by ush_63100


Get frequency of tokens by group in pandas

1  Asked on November 22, 2021 by ravanelli


Repeat vector elements according to values in matrix

2  Asked on November 22, 2021 by maksim-tarasenko


Ask a Question

Get help from others!

© 2023 All rights reserved. Sites we Love: PCI Database, UKBizDB, Menu Kuliner, Sharing RPP