Abstract: Methods, systems, and apparatuses, including computer programs encoded on computer-readable media, for receiving an ordered list of nodes that defines contents of a transaction document. The one or more nodes include a data field associated with one or more data items. Transaction data associated one or more data items is received. Each node of the ordered list of nodes is executed to generate a result tree that includes at least a portion of the transaction data. The result tree is sent to a remote device that displays a first document in a first format based upon the result tree. A second document is rendered in a second format based upon the result tree and sent to the remote device.