GET:

<?php
define("APIKEY", "[apikey]");
define("USER", "[email]");
define("URL", "https://api.julitec.com/api");

function curlWrap($url, $json, $action)
{
	$ch = curl_init();
	curl_setopt($ch, CURLOPT_MAXREDIRS, 10 );
	curl_setopt($ch, CURLOPT_URL, URL.$url);
	curl_setopt($ch, CURLOPT_USERPWD, USER. ":" .APIKEY);
	switch($action){
		case "POST":
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
			curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
			break;
		case "GET":
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET");
			break;
		case "PUT":
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PUT");
			curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
		default:
			break;
	}
	curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-type: application/json'));
	curl_setopt($ch, CURLOPT_USERAGENT, "MozillaXYZ/1.0");
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
	curl_setopt($ch, CURLOPT_TIMEOUT, 10);
	$output = curl_exec($ch);
	curl_close($ch);
	$decoded = json_decode($output);
	return $decoded;
}


$data = curlWrap("/contact?MainCategory=Kunde", null, "GET");

?> 

POST:

<?php
define("APIKEY", "[apikey]");
define("USER", "[email]");
define("URL", "https://api.julitec.com/api"); 

function curlWrap($url, $json, $action)
{
	$ch = curl_init();
	curl_setopt($ch, CURLOPT_MAXREDIRS, 10 );
	curl_setopt($ch, CURLOPT_URL, URL.$url);
	curl_setopt($ch, CURLOPT_USERPWD, USER. ":" .APIKEY);
	switch($action){
		case "POST":
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
			curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
			break;
		case "GET":
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET");
			break;
		case "PUT":
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PUT");
			curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
		default:
			break;
	}
	curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-type: application/json'));
	curl_setopt($ch, CURLOPT_USERAGENT, "MozillaXYZ/1.0");
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
	curl_setopt($ch, CURLOPT_TIMEOUT, 10);
	$output = curl_exec($ch);
	curl_close($ch);
	$decoded = json_decode($output);
	return $decoded;
}


$create = json_encode(array('Organization' => 'API TEST_2', 'Address' => array('City' => 'Fuerth', 'Street' => 'Nuernberger Strasse 23')), JSON_FORCE_OBJECT);

$data = curlWrap("/mixed", $create, "POST");
?>

PUT:

<?php
define("APIKEY", "[apikey]");
define("USER", "[email]");
define("URL", "https://api.julitec.com/api"); 

function curlWrap($url, $json, $action)
{
	$ch = curl_init();
	curl_setopt($ch, CURLOPT_MAXREDIRS, 10 );
	curl_setopt($ch, CURLOPT_URL, URL.$url);
	curl_setopt($ch, CURLOPT_USERPWD, USER. ":" .APIKEY);
	switch($action){
		case "POST":
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
			curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
			break;
		case "GET":
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET");
			break;
		case "PUT":
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PUT");
			curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
		default:
			break;
	}
	curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-type: application/json'));
	curl_setopt($ch, CURLOPT_USERAGENT, "MozillaXYZ/1.0");
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
	curl_setopt($ch, CURLOPT_TIMEOUT, 10);
	$output = curl_exec($ch);
	curl_close($ch);
	$decoded = json_decode($output);
	return $decoded;
}

/*ContactId we want to access*/
$contactId = "999";

$getData = curlWrap("/contact/" .$contactId, null, "GET");

$putData = $getData;

$putData->{'CustomerNo'} = '25';
/*Here you can change all fields you want*/

$put = curlWrap("/contact/". $contactId, json_encode($putData), "PUT");
?>