corepack

Corepack is a zero-runtime-dependency Node.js script that acts as a bridge between Node.js projects and the package managers they are intended to be used with during development. In practical terms, Corepack lets you use Yarn, npm, and pnpm without having to install them.

How to Install

Default Installs

Corepack is distributed by default with all recent Node.js versions. Run corepack enable to install the required Yarn and pnpm binaries on your path.

Manual Installs

npm uninstall -g yarn pnpm

# That should be enough, but if you installed Yarn without going through npm it might
# be more tedious - for example, you might need to run `brew uninstall yarn` as well.

npm install -g corepack

Usage

When Building Packages

Just use your package managers as you usually would. Run yarn install in Yarn projects, pnpm install in pnpm projects, and npm in npm projects. Corepack will catch these calls, and depending on the situation:

• If the local project is configured for the package manager you're using, Corepack will silently download and cache the latest compatible version.

• If the local project is configured for a different package manager, Corepack will request you to run the command again using the right package manager - thus avoiding corruptions of your install artifacts.

• If the local project isn't configured for any package manager, Corepack will assume that you know what you're doing, and will use whatever package manager version has been pinned as "known good release". Check the relevant section for more details.

When Authoring Packages

Set your package's manager with the packageManager field in package.json:

{
  "packageManager": "[email protected]+sha224.953c8233f7a92884eee2de69a1b92d1f2ec1655e66d08071ba9a02fa"
}

Here, yarn is the name of the package manager, specified at version 3.2.3, along with the SHA-224 hash of this version for validation. [email protected] is required. The hash is optional but strongly recommended as a security practice. Permitted values for the package manager are yarn, npm, and pnpm.

Known Good Releases

When running Corepack within projects that don't list a supported package manager, it will default to a set of Known Good Releases. In a way, you can compare this to Node.js, where each version ships with a specific version of npm.

If there is no Known Good Release for the requested package manager, Corepack looks up the npm registry for the latest available version and cache it for future use.

The Known Good Releases can be updated system-wide using the --activate flag from the corepack prepare and corepack hydrate commands.

Offline Workflow

The utility commands detailed in the next section.

• Either you can use the network while building your container image, in which case you'll simply run corepack prepare to make sure that your image includes the Last Known Good release for the specified package manager.

  • If you want to have all Last Known Good releases for all package managers, just use the --all flag which will do just that.

• Or you're publishing your project to a system where the network is unavailable, in which case you'll preemptively generate a package manager archive from your local computer (using corepack prepare -o) before storing it somewhere your container will be able to access (for example within your repository). After that it'll just be a matter of running corepack hydrate <path/to/corepack.tgz> to setup the cache.

Utility Commands

corepack <binary name>[@<version>] [... args]

This meta-command runs the specified package manager in the local folder. You can use it to force an install to run with a given version, which can be useful when looking for regressions.

Note that those commands still check whether the local project is configured for the given package manager (ie you won't be able to run corepack yarn install on a project where the packageManager field references pnpm).

corepack enable [... name]

This command will detect where Corepack is installed and will create shims next to it for each of the specified package managers (or all of them if the command is called without parameters). Note that the npm shims will not be installed unless explicitly requested, as npm is currently distributed with Node.js through other means.

If the file system where the corepack binary is located is read-only, this command will fail. A workaround is to add the binaries as alias in your shell configuration file (e.g. in ~/.bash_aliases):

alias yarn="corepack yarn"
alias yarnpkg="corepack yarnpkg"
alias pnpm="corepack pnpm"
alias pnpx="corepack pnpx"
alias npm="corepack npm"
alias npx="corepack npx"

On Windows PowerShell, you can add functions using the $PROFILE automatic variable:

echo "function yarn { corepack yarn `$args }" >> $PROFILE
echo "function yarnpkg { corepack yarnpkg `$args }" >> $PROFILE
echo "function pnpm { corepack pnpm `$args }" >> $PROFILE
echo "function pnpx { corepack pnpx `$args }" >> $PROFILE
echo "function npm { corepack npm `$args }" >> $PROFILE
echo "function npx { corepack npx `$args }" >> $PROFILE

corepack disable [... name]

This command will detect where Node.js is installed and will remove the shims from there.

corepack prepare [... name@version]

This command will download the given package managers (or the one configured for the local project if no argument is passed in parameter) and store it within the Corepack cache. If the -o,--output flag is set (optionally with a path as parameter), an archive will also be generated that can be used by the corepack hydrate command.

corepack hydrate <path/to/corepack.tgz>

This command will retrieve the given package manager from the specified archive and will install it within the Corepack cache, ready to be used without further network interaction.

Environment Variables

• COREPACK_DEFAULT_TO_LATEST can be set to 0 in order to instruct Corepack not to lookup on the remote registry for the latest version of the selected package manager.

• COREPACK_ENABLE_NETWORK can be set to 0 to prevent Corepack from accessing the network (in which case you'll be responsible for hydrating the package manager versions that will be required for the projects you'll run, using corepack hydrate).

• COREPACK_ENABLE_STRICT can be set to 0 to prevent Corepack from throwing error if the package manager does not correspond to the one defined for the current project. This means that if a user is using the package manager specified in the current project, it will use the version specified by the project's packageManager field. But if the user is using other package manager different from the one specified for the current project, it will use the system-wide package manager version.

• COREPACK_ENABLE_PROJECT_SPEC can be set to 0 to prevent Corepack from checking if the package manager corresponds to the one defined for the current project. This means that it will always use the system-wide package manager regardless of what is being specified in the project's packageManager field.

• COREPACK_HOME can be set in order to define where Corepack should install the package managers. By default it is set to %LOCALAPPDATA%\node\corepack on Windows, and to $HOME/.cache/node/corepack everywhere else.

• COREPACK_ROOT has no functional impact on Corepack itself; it's automatically being set in your environment by Corepack when it shells out to the underlying package managers, so that they can feature-detect its presence (useful for commands like yarn init).

• COREPACK_NPM_REGISTRY sets the registry base url used when retrieving package managers from npm. Default value is https://registry.npmjs.org

• COREPACK_NPM_TOKEN sets a Bearer token authorization header when connecting to a npm type registry.

• COREPACK_NPM_USERNAME and COREPACK_NPM_PASSWORD to set a Basic authorization header when connecting to a npm type registry. Note that both environment variables are required and as plain text. If you want to send an empty password, explicitly set COREPACK_NPM_PASSWORD to an empty string.

• HTTP_PROXY, HTTPS_PROXY, and NO_PROXY are supported through node-proxy-agent.

Troubleshooting

Networking

There are a wide variety of networking issues that can occur while running corepack commands. Things to check:

• Make sure your network connection is active.
• Make sure the host for your request can be resolved by your DNS; try using curl [URL] (ipv4) and curl -6 [URL] (ipv6) from your shell.
• Check your proxy settings (see Environment Variables).

Contributing

See CONTRIBUTING.md.

Design

See DESIGN.md.

License (MIT)

See LICENSE.md.