HubSpot has released a new API for Social Media Publishing. This API allows programmatic scheduling of new social messages to Twitter, Facebook, LinkedIn or any social media accounts that have been configured within HubSpot. It also enables the collecting of analytics on published messages. The Social Media API is now available to customers and marketplace app providers on behalf of customers
What is an API?
API stands for "application programming interface". It enables the automatic exchange of information between systems. In other words, using APIs applications talk to each other without any user intervention. HubSpot opens up APIs to enable partners or tech-savvy customers to connect with our software and and expand upon its uses. Opening this and other APIs is a way for HubSpot to foster continuous innovation and improvements in our software.
You can get more information on the available APIs here
API help forum