Aggregating interactions for content items

A request to generate a first post data item for display at a first location is received, the first post data item including a reference to a content item located at a second location. Based on the reference to the content item, a content identifier associated with the content item is determined. The content identifier is associated with the post data item. One or more post data items are retrieved based on the content identifier and displaying the one or more post data items at the second location, the one or more post data items including the first post data item. A file identified by the reference to the content item is accessed to read a notification tag associated with the content item, the notification tag identifying a destination to which notifications may be sent. A notification is sent to the destination, the notification identifying the post data item.