Abstract: Variety of approaches to provide a copy of a notebook document are described. A copy application programming interface (API) of a productivity service initiates operations to copy a source notebook document upon receiving a request to copy a designated portion of the source notebook document to a destination. In response to the received request, the copy API retrieves serialized data stored in a source section file associated with the designated portion of the source notebook document. The serialized data is provided such that a new portion of a destination notebook document is constructed at the destination based at least in part on the serialized data.