Fast, reliable, and secure dependency management.
Yarn is a modern package manager split into various packages. Its novel architecture allows to do things currently impossible with existing solutions:
- Yarn supports plugins; adding a plugin is as simple as adding it into your repository
- Yarn supports Node by default but isn't limited to it - plugins can add support for other languages
- Yarn supports workspaces natively, and its CLI takes advantage of that
- Yarn uses a portable shell to execute package scripts, guaranteeing they work the same way on Windows and Linux
- Yarn is first and foremost a Node API that can be used programmatically (via berry-core)
- Yarn is written in TypeScript, and fully typechecked
Consult the dedicated page for more details.
The documentation is being reworked to contain an updated content and a refreshed design, and the most up-to-date version can be found on the repository GitHub pages: yarnpkg.github.io/berry
The following packages are generic and can be used in a variety of purposes (including to implement other package managers, but not only):
- @berry/core allows any application to manipulate a project programmatically.
- @berry/fslib is a set of tools to efficiently abstract filesystem accesses.
- @berry/json-proxy allows to temporarily convert any POD object to an immutable object.
- @berry/libzip contains zlib+libzip bindings compiled to WebAssembly.
- @berry/parsers can be used to parse Syml and the language used by berry-shell.
- @berry/pnp can be used to generate Plug'n'Play-compatible hooks.
- @berry/pnpify is a CLI tool to transparently add PnP support to various tools.
- @berry/shell is a portable bash-like shell interpreter.
The following packages are plugins for Berry and can be installed through berry add plugin <plugin-name>. Note that some of them are typically already shipped with the regular Yarn bundles. Such plugins are marked with a star (★).
- plugin-constraints★ adds support for
yarn constraints checkandyarn constraints fix. - plugin-dlx★ adds support for the
yarn dlxcommand. - plugin-essentials★ adds various commands deemed necessary for a package manager (add, remove, ...).
- plugin-exec adds support for using
exec:references as dependencies. - plugin-file★ adds support for using
file:references as dependencies. - plugin-github★ adds support for using Github references as dependencies. This plugin doesn't use git.
- plugin-http★ adds support for using straight URL references as dependencies (tgz archives only).
- plugin-init★ adds support for the
yarn initcommand. - plugin-link★ adds support for using
link:andportal:references as dependencies. - plugin-npm★ adds support for using semver ranges as dependencies, resolving them to an NPM-like registry.
- plugin-npm-cli★ adds support for the NPM-specific commands (
yarn npm login,yarn npm publish, ...). - plugin-pack★ adds support for the
yarn packcommand. - plugin-stage adds support for the
yarn stagecommand. - plugin-pnp★ adds support for installing Javascript dependencies through the Plug'n'Play specification.
- plugin-typescript★ improves the user experience when working with TypeScript.
- plugin-workspace-tools adds support for the
yarn workspaces foreachcommand.
To create your own plugin, please refer to the documentation.
The following packages are meant to be used by Yarn itself, and probably won't be useful to other applications:
- @berry/builder contains a CLI tool to package berry and its plugins.
- @berry/cli is a CLI entry point built on top of @berry/core.
Clone this repository, then run the following commands:
$> yarn build:cli
How it works
After building the CLI your global yarn will immediatly start to reflect your local changes. This is because Yarn will pick up the yarnPath settings in this repository's .yarnrc.yml, which is configured to use the newly built CLI if available.
Works out of the box!
Note that no other command is needed! Given that our dependencies are checked-in within the repository (within the .yarn/cache directory), you don't even need to run yarn install. Everything just works right after cloning the project, and is guaranteed to continue to work ten years from now 🙂