Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for searching a database storing unassembled content items. The method may include actions of receiving a query for a content item to present in the application, identifying an unassembled content item that is associated with (i) a program logic type and (ii) program logic modification tags, determining whether the client device requires an updated copy of a program logic item that includes instructions for rendering an assembled version of the unassembled content item, and transmitting, to an application program interface, data that includes (i) the unassembled content item and (ii) the modified program logic that cause the client device to render an assembled version of the content item at the client device in a programming language of the application using the program logic.

Abstract: Secure cross-frame communication between frames in a web browser may be achieved using encryption. The communication may occur between frames that pass messages to one another via an untrusted, and potentially malicious, intermediary. To prevent an intermediary from reading the content of messages, frames may agree on and use a shared secret encryption key to encrypt messages. This key may be created by passing tokens between frames that want to securely communicate.