Methods, systems, and apparatus, including computer programs encoded on a computer-readable storage medium for implementing one or more application programming interfaces (APIs) that configure applications stored in an electronic device are described. An application may be configured to receive event information from various sources based on user preferences and application permissions. In response to receiving the event information, the app may determine whether a notification should be issued to a user. This determination may be made based on various factors such as the type of event, user history, contextual data, ranking data, and application permissions. The notifications may include one or more of messages to the user and recommended actions for consideration by the user. The actions may include sharing data with other users who share a presence or interest in an event with the user.