NPM (NPM v0.6.0)

npm package manager for Elixir.

Resolves, fetches, and installs npm packages using Mix tasks. Dependencies are declared in package.json and locked in npm.lock.

Mix tasks

mix npm.install              # Install all deps from package.json
mix npm.install lodash       # Add latest version
mix npm.install lodash@^4.0  # Add with specific range
mix npm.install --frozen     # Fail if lockfile is stale (CI mode)
mix npm.get                  # Fetch locked deps without resolving
mix npm.remove lodash        # Remove a package
mix npm.list                 # List installed packages

Packages are cached globally in ~/.npm_ex/cache/ and linked into node_modules/ via symlinks (macOS/Linux) or copies (Windows).

Summary

Functions

add(name, range \\ "latest", opts \\ [])

Add a package to package.json and install all dependencies.

get()

Fetch locked dependencies without re-resolving.

install(opts \\ [])

Install all dependencies from package.json (project context).

install(deps, opts)

Install npm packages in a script context, without a Mix project.

install_dir!()

Returns the root directory of the current NPM.install/2 installation.

installed?()

Returns whether NPM.install/2 has been called in this VM.

list()

List installed packages with versions.

node_modules_dir!()

Returns the node_modules path of the current NPM.install/2 installation.

remove(name)

Remove a package from package.json and re-install.

update()

Update all packages to the latest versions matching their ranges.

update(name)

Update a specific package to the latest version matching its range.

Functions

add(name, range \\ "latest", opts \\ [])

@spec add(String.t(), String.t(), keyword()) :: :ok | {:error, term()}

Add a package to package.json and install all dependencies.

Options

:dev - when true, adds to devDependencies instead of dependencies

get()

@spec get() :: :ok | {:error, term()}

Fetch locked dependencies without re-resolving.

Reads npm.lock and populates the global cache and node_modules/ for any missing packages.

install(opts \\ [])

@spec install(keyword()) :: :ok | {:error, term()}

Install all dependencies from package.json (project context).

Options

:frozen - when true, fails if npm.lock doesn't match package.json instead of re-resolving. Useful for CI.
:production - when true, skips devDependencies.

install(deps, opts)

@spec install(
  map(),
  keyword()
) :: :ok

Install npm packages in a script context, without a Mix project.

Works like Mix.install/2 — installs to a content-addressed cache directory, is idempotent, and can only be called once per VM (raises on different deps).

NPM.install(%{"tailwindcss" => "^4.2.2"})

After installation, use NPM.install_dir!/0 and NPM.node_modules_dir!/0 to locate the installed packages.

Options

:force — reinstall even if cached (default: false)

install_dir!()

@spec install_dir!() :: String.t()

Returns the root directory of the current NPM.install/2 installation.

Raises if NPM.install/2 has not been called.

installed?()

@spec installed?() :: boolean()

Returns whether NPM.install/2 has been called in this VM.

list()

@spec list() :: {:ok, [{String.t(), String.t()}]} | {:error, term()}

List installed packages with versions.

Returns a list of {name, version} tuples.

node_modules_dir!()

@spec node_modules_dir!() :: String.t()

Returns the node_modules path of the current NPM.install/2 installation.

Raises if NPM.install/2 has not been called.

remove(name)

@spec remove(String.t()) :: :ok | {:error, term()}

Remove a package from package.json and re-install.

update()

@spec update() :: :ok | {:error, term()}

Update all packages to the latest versions matching their ranges.

Clears the resolver cache and re-resolves from scratch.

update(name)

@spec update(String.t()) :: :ok | {:error, term()}

Update a specific package to the latest version matching its range.

Only re-resolves the named package; other locked versions are preserved.