Update 1: 2018/09/11 6:34am PDT
Google has announced that the Google Photos Library API is now generally available. Developers interested in integrating Google Photos into their products can check out the developer documentation.
Google introduced a program today that will allow developers to integrate Google Photos into their services. The program includes an API that lets third-party services use some of the features Google Photos offers, such as the platform's powerful search functionality.Read More
[Update: Google Photos API generally available] Google launches Google Photos partner program was written by the awesome team at Android Police.