RESTful services in Drupal 8

namespace Drupal\todo\Plugin\rest\resource;

/**
 * Provides a resource to get all TODOs.
 *
 * @RestResource(
 *   id = "todos",
 *   label = @Translation("Expose TODOs in our site"),
 *   uri_paths = {
 *     "canonical" = "/todos/{entity}"
 *   }
 * )
 */
class Todo extends ResourceBase {
// ...
}

id: entity.todo
plugin_id: 'entity:todo'
granularity: method
configuration:
  GET:
    supported_formats:
      - json
    supported_auth:
      - basic_auth
      - cookie

$ curl --include   --request POST   --header 'Content-type: application/json'   http://localhost:8000/user/login?_format=json   --data-binary '{"name":"admin", "pass":"admin"}'

{
   "current_user":{
      "uid":"1",
      "roles":[
         "authenticated",
         "administrator"
      ],
      "name":"admin"
   },
   "csrf_token":"adt7n0W1REQ95RLvJ28PcdnUFB5LPMJ1bl_nybjl2m8",
   "logout_token":"A02NsXEcHeSwrF6pw75_2nZOoLGMSYXAODqRALT6mEQ"
}

$ curl --include \
--request POST \
--header 'Content-type: application/json' \
--header 'X-CSRF-Token: adt7n0W1REQ95RLvJ28PcdnUFB5LPMJ1bl_nybjl2m8' \
--header 'Cookie: SESS49960de5880e8c687434170f6476605b=30Nw-n-sEDBJeCVJryqkhhDLny1FudLT0KGONfafss0' \
http://localhost:8000/entity/node?_format=json \
--data-binary '{"title":[{"value":"Example node title with body"}],"type":[{"target_id":"article"}], "body": [{"value":"FOOO Habitant eligendi nobis nonummy, rerum facere. Error atque, praesentium, suspendisse laoreet nemo! Magni cupiditate sociosqu hac? Tristique. Necessitatibus nisl ab! Ac netus dolore leo feugiat suscipit magnam tortor mi placerat."}], "field_tags":[{"target_id": 3}, {"target_id": 2}]}'

{"nid":[{"value":"1"}],"uuid":[{"value":"182973da-694d-443a-9082-e485665e3bd4"}],"vid":[{"value":"1"}],"langcode":[{"value":"en"}],"type":[{"target_id":"article","target_type":"node_type","target_uuid":"95f1b114-3c97-4e8c-b18b-c5c8a1f7f7a5"}],"title":[{"value":"Example node title with body"}],"uid":[{"target_id":"1","target_type":"user","target_uuid":"4aa78309-82d2-4d60-b01a-78b7f8c1113a","url":"\/user\/1"}],"status":[{"value":true}],"created":[{"value":1489805159}],"changed":[{"value":1489805159}],"promote":[{"value":true}],"sticky":[{"value":false}],"revision_timestamp":[{"value":1489805159}],"revision_uid":[{"target_id":"1","target_type":"user","target_uuid":"4aa78309-82d2-4d60-b01a-78b7f8c1113a","url":"\/user\/1"}],"revision_log":[],"revision_translation_affected":[{"value":true}],"default_langcode":[{"value":true}],"path":[],"body":[{"value":"FOOO Habitant eligendi nobis nonummy, rerum facere. Error atque, praesentium, suspendisse laoreet nemo! Magni cupiditate sociosqu hac? Tristique. Necessitatibus nisl ab! Ac netus dolore leo feugiat suscipit magnam tortor mi placerat.","format":null,"summary":null}],"comment":[{"status":2,"cid":0,"last_comment_timestamp":0,"last_comment_name":null,"last_comment_uid":0,"comment_count":0}],"field_image":[],"field_tags":[{"target_id":3,"target_type":"taxonomy_term","target_uuid":"07600395-da93-4433-9f5d-d3f0f60f34dd","url":"\/taxonomy\/term\/3"},{"target_id":2,"target_type":"taxonomy_term","target_uuid":"62eaca3a-6ed1-4bd2-a4c4-4f1a3dab1559","url":"\/taxonomy\/term\/2"}]}