Each RRPproxy account can set up users and groups. Specific rights can be applied for each user and each group, granting access to objects, as well as what operations are allowed on given objects.
To log into the web interface as a certain user (or send a command to the API) you have to append the username to the account name, connected by ":", as login name (i.e. login=[accountname]:[username]) and enter the corresponding user password.