Installing Package Using NPM from Private Repository

What is the correct syntax in "package.json" so I can install a package from a private npm repository.

My repository is running sinopia at http://localhost:4873 and I have a package called "foo". I can upload without issue

I want something like this in my package.json file:

{
  "name": "y",
  ...
  "dependencies": {
      "foo": "http://localhost:4873/"
  },
}

Thanks

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Link to original article：https://stackoverflow.com/questions/30769300/installing-package-using-npm-from-private-repository