node/deps/npm/doc/cli/npm-link.md

npm-link(1) -- Symlink a package folder

SYNOPSIS

npm link (in package dir)
npm link [<@scope>/]<pkg>[@<version>]

alias: npm ln

DESCRIPTION

Package linking is a two-step process.

First, npm link in a package folder will create a symlink in the global folder {prefix}/lib/node_modules/<package> that links to the package where the npm link command was executed. (see npm-config(7) for the value of prefix).

Next, in some other location, npm link package-name will create a symbolic link from globally-installed package-name to node_modules/ of the current folder.

Note that package-name is taken from package.json, not from directory name.

The package name can be optionally prefixed with a scope. See npm-scope(7). The scope must be preceded by an @-symbol and followed by a slash.

When creating tarballs for npm publish, the linked packages are "snapshotted" to their current state by resolving the symbolic links.

This is handy for installing your own stuff, so that you can work on it and test it iteratively without having to continually rebuild.

For example:

cd ~/projects/node-redis    # go into the package directory
npm link                    # creates global link
cd ~/projects/node-bloggy   # go into some other package directory.
npm link redis              # link-install the package

Now, any changes to ~/projects/node-redis will be reflected in ~/projects/node-bloggy/node_modules/node-redis/. Note that the link should be to the package name, not the directory name for that package.

You may also shortcut the two steps in one. For example, to do the above use-case in a shorter way:

cd ~/projects/node-bloggy  # go into the dir of your main project
npm link ../node-redis     # link the dir of your dependency

The second line is the equivalent of doing:

(cd ../node-redis; npm link)
npm link node-redis

That is, it first creates a global link, and then links the global installation target into your project's node_modules folder.

If your linked package is scoped (see npm-scope(7)) your link command must include that scope, e.g.

npm link @myorg/privatepackage

SEE ALSO

• npm-developers(7)
• package.json(5)
• npm-install(1)
• npm-folders(5)
• npm-config(1)
• npm-config(7)
• npmrc(5)