yarn

Install every dependency listed in `package.json`, creating or refreshing `node_modules` and `yarn.lock`.

--frozen-lockfile fail if lock would change (CI); --production / --prod skip devDeps; --no-progress; --silent

Install only if `yarn.lock` matches `package.json` exactly. Used in CI to guarantee reproducible builds.

Berry default: uses Plug'n'Play when `nodeLinker: pnp` is in `.yarnrc.yml`, otherwise falls back to `node_modules`. Caches in `.yarn/cache`.

--immutable fail on lockfile drift (Berry equivalent of --frozen-lockfile); --inline-builds; --mode=update-lockfile

Switch the Yarn binary in the project. Common: `yarn set version stable`, `yarn set version 4.0.2`, `yarn set version classic`.

Add a runtime dep and write to `package.json` + lockfile. Classic writes to `dependencies`, Berry same.

<pkg>@<version|range>; --dev / -D; --exact / -E; --optional / -O; --peer

Add to `devDependencies`.

Install a specific version, dist-tag (`@latest`, `@next`, `@canary`), or git URL.

Install a tool globally (Classic 1.x). Berry uses `yarn dlx` for one-shot binaries and recommends `corepack` for global tools.

Remove a package from `node_modules` and the relevant `dependencies` / `devDependencies` section.

Upgrade all dependencies within their current semver ranges; `yarn upgrade --latest` jumps to the newest available release and rewrites the range.

--latest; --pattern <glob>; --caret; --exact; -i / --interactive

Upgrade a single package to a specific version.

Run a script from `package.json`. `yarn test`, `yarn start`, `yarn build` are shorthand.

-- <args> forward args to the script

Same as `yarn run <script>` — call any defined script by name without the `run` keyword.

Run a package binary on demand without installing it locally (Berry equivalent of `npx`). Caches to `~/.yarn/berry/cache`.

-p / --package pick package; -q / --quiet

Add a dependency to the root of a monorepo workspace (1.x).

Add a dep to a single named workspace within the monorepo.

Run a script in every workspace. `yarn workspaces foreach run <script>` (Berry) supports concurrency and topology order.

--parallel; --topological; --continue; --interlaced

Print the dependency tree. `--pattern <regex>` filters; `--depth 0` shows direct deps only.

--depth=N; --pattern; --json

Explain why a given package is installed — the chain of dependencies that brought it in.

Print registry metadata for a package — versions, dependencies, dist-tags, readme excerpt. Roughly equivalent to `npm view`.

<pkg>@<version>; <pkg> readme; <pkg> dependencies

List every license across the dependency tree (SPDX identifier + author). Useful for license-compliance reviews.

Write a config entry to `.yarnrc.yml` (Berry). Common keys: `nodeLinker`, `npmRegistryServer`, `enableTelemetry`, `yarnPath`.

Read a single config entry.

Wipe the Yarn cache (Classic: `~/.yarn-cache`; Berry: `.yarn/cache`).

Print the cache directory path.

Berry only — import `package-lock.json` from npm into Yarn's lockfile format.

Berry only — enforce project-wide dependency rules written in Prolog in `constraints.pro` (e.g. every workspace must depend on the same React version).

Berry — proxy to the npm registry's advisory feed. Reports vulnerabilities in the lockfile.

--severity info|low|moderate|high|critical; --json

Print the current Yarn version (works for both Classic and Berry).

Create a `package.json` interactively or with `-y` for defaults.

-y accept defaults; -p / --private mark as private

Bundle the current package into a tarball without publishing — useful for offline distribution.

--filename; --pack-destination <dir>

Extract a single package from the PnP zip store into a normal `node_modules/<pkg>` so it can be required the old-fashioned way (workaround for incompatible tooling).

Recompile native addons for the current Node ABI. Berry needs this for packages with native deps under PnP.