There are three standard ways to manage API authentication these days: API keys, OAuth tokens and JSON Web tokens (JWT). Adam Duvander over at the Zapier engineering blog explains how and when to use them. The humble API key is the common and earliest form of API authentication.
Skybiometry's cloud-based face detection API serves as a drop-in replacement for face.com's API. This REST-based API can be used in combination with almost any programming language, making it possible to integrate with any device that has internet connectivity.