Local dependency in package.json

npm >= 2.0.0

This feature was implemented in the version 2.0.0 of npm. Local paths can be saved using npm install -S or npm install --save, using any of these forms:

../foo/bar
~/foo/bar
./foo/bar
/foo/bar

Example package.json:

{
  "name": "baz",
  "dependencies": {
    "bar": "file:../foo/bar"
  }
}

npm ls:

app@0.0.1 /private/tmp/app
└── somelocallib@0.0.1 -> /private/tmp/somelocallib

npm < 2.0.0

Put somelocallib as dependency in your package.json as normal:

"dependencies": {
  "somelocallib": "0.0.x"
}

Then run npm link ../somelocallib and npm will install the version you’re working on as a symlink.

Reference: link(1)