Google announced the new People API, which lets developers retrieve data about authenticated users' connections from their Contacts.
Whereas in the past, developers had to make multiple calls to the Google+ API for user profiles and the Contacts API for contacts, they can now get the best of both worlds with a single API.
Google says the People API utilizes the newest protocols and technologies and will eventually replace the Contacts API (which uses the GData protocol). The company says in a post on its developer blog:
For example, if your user has contacts in her private contact list, a call to the API (if she provides consent to do so) will retrieve a list containing the contacts merged with any linked profiles. If the user grants the relevant scopes, the results are returned as a people.connections.list object. Each person object in this list will have a resourceName property, which can be used to get additional data about that person with a call to people.get.
The API is built on HTTP and JSON, so any standard HTTP client can send requests to it and parse the response. However, applications need to be authorized to access the APIs so you will need to create a project on the Google Developers Console in order to get the credentials you need to access the service. All the steps to do so are here. If you’re new to the Google APIs and/or the Developers Console, check out this first in a series of videos to help you get up-to-speed.
Not only does the new API combine the purposes of two others, it includes additional data that wasn't available before, including private addresses, phone numbers, emails, and birthdays. This of course is only for users who have given permission.
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