User Custom Api

custom_clients_base_api_UserCustomApi.php

<?php
 if(!defined('sugarEntry') || !sugarEntry) die('Not A Valid Entry Point');
/*********************************************************************************
 * By installing or using this file, you are confirming on behalf of the entity
 * subscribed to the SugarCRM Inc. product ("Company") that Company is bound by
 * the SugarCRM Inc. Master Subscription Agreement (“MSA”), which is viewable at:
 * http://www.sugarcrm.com/master-subscription-agreement
 *
 * If Company is not bound by the MSA, then by installing or using this file
 * you are agreeing unconditionally that Company will be bound by the MSA and
 * certifying that you have authority to bind Company accordingly.
 *
 * Copyright (C) 2004-2014 SugarCRM Inc.  All rights reserved.
 ********************************************************************************/


require_once 'include/api/SugarApi.php';

class UserCustomApi extends SugarApi
{
    public function registerApiRest()
    {
        return array(            
            'retrive_by_emails' => array(
                'reqType' => 'GET',
                'path' => array('Users','filter','email',),
                'pathVars' => array(),
                'method' => 'retriveUsersByEmailAddress',
                'shortHelp' => 'Retrieve Users by email addresses',
                'longHelp' => '',
            ),                                  
        );        
    }
   
    public function retriveUsersByEmailAddress($api, $args)
    {
        $users = array();
        //$users['args'] = $args;
        $emailAddresses = explode(",",preg_replace('/[\[\]\"]/', '', $args['email_addresses']));

        $email = BeanFactory::getBean('EmailAddresses');
        $q = $email->getEmailsQuery('Users');
        $q->joinRaw("JOIN users ON users.deleted = 0 and users.id = ear.bean_id", array('alias' => 'users'));
        $q->where()
        	->in("email_addresses.email_address", $emailAddresses)
        	->equals("ear.primary_address", "1");

        $q->select->field("ear.bean_id");
        $q->select->fieldRaw("users.user_name");
        $email_rows = $q->execute();
        $users['users'] = $email_rows;        
        return $users;
    }
}

Url: rest/v10/Users/filter/email?email_addresses=["example1@example.com","example2@example.com"]

The class name should be changed to CustomUserAPI and the filename also for it to work on Sugar 7

Here is the modification: https://gist.github.com/brakon/5e3b64099d0fe98894eccce4d570a660