This route will require authentication with a valid api_token, and then return the relevant user, as JSON. - https://laracasts.com/series/whats-new-in-laravel-5-2/episodes/5

routes.php

<?php

Route::group([
    'prefix' => 'api/v1', 
    'middleware' => ['api', 'auth:api']
], function () {

    Route::get('/', function () {
        return Auth::guard('api')->user();
    });
    
});