You can develop applications for Connections Cloud using the IBM Social Business Toolkit. The Social Business Toolkit provides is a set of extensible tools and resources for developers who want to incorporate social capabilities into their applications and business processes. Social capabilities include features and functionality that tap into the power of social interactions, business networks, community-based problem solving, and more.
You can find the IBM Social Business Toolkit documentation in this wiki. Topics includes API reference for cloud and detailed information on setting up and using Open Authorization and IBM Business Support System. You will also find documentation on how to integrate applications with IBM Connections Cloud, as well as links to the API Explorer.