can you host a private repository for your organization to use with npm?

I don't think there is an easy way to do this.

A look at the npm documentation tells us, that it is possible:

Can I run my own private registry?

Yes!

The easiest way is to replicate the couch database, and use the same (or similar) design doc to implement the APIs.

If you set up continuous replication from the official CouchDB, and then set your internal CouchDB as the registry config, then you'll be able to read any published packages, in addition to your private ones, and by default will only publish internally. If you then want to publish a package for the whole world to see, you can simply override the --registry config for that command.

There's also an excellent tutorial on how to create a private npm repository in the clock blog.

EDIT (2017-02-26):

Not really new, but there are now paid plans to host private packages on npm.

Over the years, npm has become a factor for many non-Node.js companies, too, through the huge frontend ecosystem that's built upon npm. If your company is already running Sonatype Nexus for hosting Java projects internally, you can also use it for hosting internal npm packages.

Other options include JFrog Artifactory and Inedo ProGet, but I haven't used those.

There is an easy to use npm package to do this. https://www.npmjs.org/package/sinopia

In a nutshell, Sinopia is a private/caching npm repository server that you can setup with zero configuration.

Sinopia can be used to :

• publish own private packages without exposing it to the public
• cache only public packages that are used (there is no need to have to replicate the whole public registery)
• override public packages with a modified version that have been produced internally.

Verdaccio is what I was looking for and it deserves it's own answer ;) It is an actively maintained fork of Sinopia (highly upvoted answer here). It is a npm registry as a npm package, and can be found

here: https://github.com/verdaccio/verdaccio,
here: https://www.verdaccio.org,
and on port number: 4873

Run using PM2

npm i -g verdaccio pm2
pm2 start --name verdaccio `which verdaccio`
pm2 save

Run using docker

docker run -it --rm --detach --name verdaccio -p 4873:4873 verdaccio/verdaccio

Run using Helm

helm repo add verdaccio https://charts.verdaccio.org
helm repo update
helm install verdaccio/verdaccio

https://github.com/isaacs/npmjs.org/ : In npm version v1.0.26 you can specify private git repositories urls as a dependency in your package.json files. I have not used it but would love feedback. Here is what you need to do:

{
    "name": "my-app",
    "dependencies": {
        "private-repo": "git+ssh://[email protected]:my-app.git#v0.0.1",
    }
}

The following post talks about this: Debuggable: Private npm modules