The SocialHub service provides a REST API for sites to publish posts and synchronize comments with social networks.
SocialHub Publisher API documentation
(Developers)

The SocialHub API module provides functionality for easily accessing the SocialHub Publisher API, automatically taking care of security and authentication.
SocialHub API module documentation
(Developers)

The SocialHub Entities module provides entity types representing the datatypes of the SocialHub Publisher API. All actions applied on these entities will automatically result in proper API requests.