verdaccio/wiki/auth.md

Authentification

The authentification is tied to the auth plugin you are using. The package restrictions also is handled by the Package Access.

The client authentification is handled by npm client itself. Once you login to the application:

npm adduser --registry http://localhost:4873

A token is generated in the npm configuration file hosted in your user home folder. For more information about .npmrc read the official documentation.

cat .npmrc 
registry=http://localhost:5555/
//localhost:5555/:_authToken="secretVerdaccioToken"
//registry.npmjs.org/:_authToken=secretNpmjsToken

Default htpasswd

In order to simplify the setup, verdaccio use a build-in plugin based on htpasswd.

auth:
  htpasswd:
    file: ./htpasswd
    # Maximum amount of users allowed to register, defaults to "+inf".
    # You can set this to -1 to disable registration.
    #max_users: 1000

Property	Type	Required	Example	Support	Description
file	string	Yes	./htpasswd	all	file that host the encrypted credentials
max_users	number	No	1000	all	set limit of users

In case to decide do not allow user to login, you can set max_users: -1.