Disclosed are methods, apparatus, systems, and computer readable storage media for interacting with components across different domains in a single user interface in an online social network. The user interface includes a first component and a second component, where the first component exposes content from a first database system at a first network domain and the second component exposes content from a second database system at a second network domain. A first interaction with the first component is received at a computing device, followed by a reference being provided in the second component, where the reference includes information related to the first interaction. A second interaction with the second component regarding the reference can be received at the computing device. Interactions between the components hosted on different database systems can occur through an application programming interface (API).