Currently Azure NoSQL solution DocumentDB doesn't have any PHP SDK. There is a REST API alternative which has several PHP wrappers on Github.
NodeJS example in Azure uses mongodb driver from npm. I can successfully crud documents on DocumentDB with that example. So with an mongo driver it's possible to crud to Azure DocumentDB. Example here
However when i try to connect to Azure DocumentDB with PHP7.0 - mongodb extension installed my server returns empty response. Example scenario
UPDATE:
Just realised I can actually connect to Azure DocumentDB in a plain php script with mongodb driver. Problem is possible occuring due to framework I am using "cakephp 2" framework.
UPDATE 2 It's not CakePHP2 but Apache(MAMP).When i isolated the problem I've seen that actually crashes are only occuring with apache. I can use the extension with nginx.