Expose Zotonic authentication via a REST API service. This example is built for use with phpBB authentication as documented here: https://wiki.phpbb.com/Authentication_plugins

service_phpbb_auth.erl

-module(service_phpbb_auth).

-svc_title("External Zotonic Authentication service").
%% You can change this to restrict access
-svc_needauth(false).

-export([process_get/2]).

-include_lib("zotonic.hrl").

process_get(_ReqData, Ctx) ->
    Username = z_context:get_q("username",Context),
    Password = z_context:get_q("password",Context),
    Response = case z_auth:logon_pw(Username, Password, Ctx) of
                   {context, _Ctx1} -> 
                       {success, true};
                    {false, _Ctx2} ->
                        {success, false}
               end,
    z_convert:to_json(Response).

Place this script in the services folder in the module or site and access it at http://localhost:8000/api/phpbb/auth