index.php

<?php
// set JSON header
header('Content-Type: application/json');
// check for version
if($_SERVER['REQUEST_URI'] === "/v1") {
	// select endpoint
	switch($_SERVER['REQUEST_URI']) {
	case "v1/user":
		require_once "endpoints/user.php";
	break;
	case "v1/post":
		require_once "endpoints/post.php";
	break;
	default:
		require_once "endpoints/default.php";
	}
} else {
	// display error if version not passed.
	header('HTTP/1.1 400 Bad Request');
	$response = array(
	"status" => "HTTP/1.1 400 Bad Request",
	"message" => "Invalid API Version",
	"acceptable" => array("v1")
	);
	echo json_encode($response, JSON_PRETTY_PRINT);
}