I already posted this on the thread, but so its more visible: https://github.com/gdamore/nanomsg/commit/60ef9d307ed9788ea93f2d02a8857c1955140f21 <https://github.com/gdamore/nanomsg/commit/60ef9d307ed9788ea93f2d02a8857c1955140f21> That’s an update to the C implementation, and to the RFC to clarify the use of the header *and* some other details that are important in WebSockets. - Garrett