Install NPM dependencies from multiple registries

TL;DR: Add this line to your .npmrc file

@{scope}:registry={your_private_registry}
//{your_private_registry}/:_authToken={YOUR_AUTH_TOKEN_HERE}

By default, npm install loads all dependencies defined in package.json from the npm package registry. However, you may encounter projects that depend on packages published to a private registry.

You can configure npm install to load public dependencies from the npm package registry and private dependencies from a private registry in a single project by following the step mentioned in the TL;DR above.

Let’s say your package.json looks like this:

"dependencies": {
  "@rayhannr/validator": "3.1.0",
  "react": "18.3.1"
}

and your .npmrc is as follows:

@rayhannr:registry=https://registry.rayhannr.org
//registry.rayhannr.org/:_authToken={YOUR_AUTH_TOKEN_HERE}

npm install will download react from the public npm registry and @rayhannr/validator from rayhannr private registry.

If the private dependencies’ names do not start with @{scope}, you may need to update the .npmrc file as follows:

registry=https://registry.rayhannr.org
//registry.rayhannr.org/:_authToken={YOUR_AUTH_TOKEN_HERE}

This configuration instructs npm install to load all dependencies from the private registry. Ensure that the private registry you’re pointing to acts as a proxy to the public npm registry, allowing you to download both public and private dependencies.

Note: It needs authorization to load dependencies from the private registry. Make sure to have an access token and pass it to your .npmrc file, replacing {YOUR_AUTH_TOKEN_HERE}. I won’t explain the authorization process in this blog.