How to install corepack

Corepack is a package manager, manager.

• The purpose of a package manager is to ensure that everyone installs exactly the same version of a projects dependencies.
  • But that is not guaranteed if different versions of the same package manager are in use
  • Differing versions can also cause lock file versioning issues (e.g. the format of the entire lock file changing back and forth without anyone really noticing)
• A package manager manager then ensures that everyone installs exactly the same version of that package manager, ensuring that your project installs are always deterministic.

Similar to how nvm/fnm lets you have multiple versions of Node.js installed simultaneously, Corepack lets you have multiple versions of npm/pnpm/yarn installed.

First uninstall your global yarn and pnpm binaries (just leave npm).

How you do this will differ depending on how you installed them in the first place. These two commands are a good place to start:

npm uninstall -g yarn pnpm
brew uninstall yarn

Now check if there are still other versions installed:

which pnpm # we want: "pnpm not found"
which yarn # we want: "yarn not found"

If which outputs “not found”, then you’re good to go. But if it outputs a file path, then that’s the binary you still need to remove.

If you don’t know how to uninstall it based on the path, then you can always just rm -rf the directory that which output.

npm i -g corepack@latest
corepack enable

Now go into any project and try to use the appropriate package manager, you’ll see something like the following:

pnpm install
! Corepack is about to download https://registry.npmjs.org/pnpm/-/pnpm-9.15.2.tgz
? Do you want to continue? [Y/n]

Hit y or enter Corepack will automatically download and start using the specified version of that package manager.

If the project doesn’t specify a package manager version (boo 👎) then it will default to a known good version; but continue reading the next section to see how to fix that.

To specify a particular package manager version in your project, you’ll want to run the corepack use command:

corepack use pnpm         # Use the latest version of pnpm
corepack use yarn@1       # Use the latest version of yarn v1
corepack use npm@11.6.0   # Use the exact version 11.6.0 of npm

This will add a packageManager field at the bottom of the package.json:

"packageManager": "pnpm@10.15.0+sha512.486ebc259d3e999a4e8691ce03b5cac4a71cbeca39372a9b762cb500cfdf0873e2cb16abe3d951b1ee2cf012503f027b98b6584e4df22524e0c7450d9ec7aa7b"

This accomplishes two things for all other developers with Corepack enabled:

1. Running pnpm install will automatically download and use pnpm version 10.15.0, ensuring deterministic project installs
2. Trying to use any other package manager to install dependencies will result in an error:

   This project is configured to use pnpm because /my-project/package.json has a "packageManager" field

If another developer does not have Corepack enabled, this will not help them at all, so you should send them this post.

The first time you come into a new project, run pnpm --version (or npm or yarn) and double check that it matches the version specified in the package.json packageManager field:

➜  pnpm --version
10.14.0

➜  cat package.json | grep packageManager
"packageManager": "pnpm@10.14.0+sha512.ad27a79641b49c3e481a16a805baa71817a04bbe06a38d17e60e2eaee83f6a146c6a688125f5792e48dd5ba30e7da52a5cda4c3992b9ccf333f9ce223af84748"

If it doesn’t match, take a look at the next section 👇.

This means that you didn’t uninstall all existing package managers before enabling corepack. First disable Corepack, then go through Step 1, then you can re-enable Corepack.

➜  corepack disable
# ...
# Go through step 1 above 👆
# ...
➜  corepack enable

➜  corepack install

Type Error: URL.canParse is not a function

Node 16 comes preinstalled with one of corepack 0.10, 0.11, or 0.12. All three of those versions of corepack predate the corepack use command, so they operate significantly different than the modern version.

But using the latest of Corepack version relies on the URL.canParse() method which was introduced in Node.js version 19.9.0 and backported 18.17.0.

This creates a catch-22 where you can’t use the Node 16 (no corepack use) or the Node 24 (url parse error) version of Corepack to get a packageManager field added to your package.json.

I’ve found two solutions to this problem:

1. Manually specify the packageManager field, without the optional hash.

   "packageManager": "yarn@1.22.22"

2. Use corepack v0.20.0; npm i -g corepack@0.20.0. I’ve found that this version specifically straddles the line where it doesn’t use URL.canParse() but does have the corepack use command.