REST principles, resource naming, HTTP methods.
GET /api/users - List users
GET /api/users/1 - Get user
POST /api/users - Create user
PUT /api/users/1 - Update user
PATCH /api/users/1 - Partial update
DELETE /api/users/1 - Delete user
GET /api/users/1/orders - User's orders
POST /api/users/1/orders - Create order for user
GET /api/orders/123 - Single order (flat)
<?php
return $this->respond($data, 200); // OK
return $this->respondCreated($data); // 201
return $this->respondNoContent(); // 204
return $this->failValidationErrors($e); // 400
return $this->failUnauthorized(); // 401
return $this->failForbidden(); // 403
return $this->failNotFound(); // 404
return $this->failServerError($message); // 500