Microsoft Graph supports social gestures in a user's social context, and provides access to useful people and social data.
Use the person resource and the People API to aggregate information about a person from across mail, contacts, and social networks. The results are ordered by their relevance based on mutliple communication, collaboration, and business relationships. The API lets you browse, sort, select, filter, or search for persons based on your criteria.
Calling out a recipient to notify and get the recipient's attention in a message is a common social gesture. The mention resource and the Mentions API provide a light-weight mechanism to call out a recipient in a message, get all the messages in which a user is notified using an @-mention, or get each mention in a message.
Create mentions in a new message
Get information about mentions in a message
Delete a mention in a message
Office Graph encapsulates the relationships between different entities in Office 365. Use Office Graph to get social insights into individual users across Office 365.