Create a custom Service

Create a Service on Drupal 8

1.  Create a custom module (here : mytest)

2. Create the service Class

Example: src/MTService.php

<?php

namespace Drupal\mytest;

class MTService {

  public function run() {

    return "This is a test Service";

  }

}

2. Create service file and add the class as service

Example : mytest.services.yml

services:

  mytest:

    class: Drupal\mytest\MTService

Now you can call your service from other modules