Services Module Authentication with Username and Password in URL
By adding the following argument entries to my retrieve operation for my custom service I was able to achieve the desired effect.

                'args' =&gt; array(
                    array(
                        'name' =&gt; 'none',
                        'type' =&gt; 'string',
                        'description' =&gt; 'Function to perform',
                        'source' =&gt; array(
                            'path' =&gt; '0'
                        ),
                        'optional' =&gt; TRUE,
                        'default' =&gt; '0',
                    ),
                    array(
                        'name' =&gt; 'version',
                        'type' =&gt; 'int',
                        'description' =&gt; 'Function to perform',
                        'source' =&gt; array(
                            'param' =&gt; 'version'
                        ),
                        'optional' =&gt; TRUE,
                        'default' =&gt; '0',
                    ),
                    array(
                        'name' =&gt; 'username',
                        'type' =&gt; 'string',
                        'description' =&gt; 'Function to perform',
                        'source' =&gt; array(
                            'param' =&gt; 'username'
                        ),
                        'optional' =&gt; FALSE,
                        'default' =&gt; '0',
                    ),
                    array(
                        'name' =&gt; 'password',
                        'type' =&gt; 'string',
                        'description' =&gt; 'Function to perform',
                        'source' =&gt; array(
                            'param' =&gt; 'password'
                        ),
                        'optional' =&gt; FALSE,
                        'default' =&gt; '0',
                    ),
                    array(
                        'name' =&gt; 'id',
                        'type' =&gt; 'string',
                        'description' =&gt; 'Function to perform',
                        'source' =&gt; array(
                            'param' =&gt; 'id'
                        ),
                        'optional' =&gt; TRUE,
                        'default' =&gt; '0',
                    ),