Thanks! I think I found that via Googling around, both leading directly to that page and via OGS API notes.
Do you know if there’s a place that provides actual notes on the wire protocol? Those generated docs for the goban library aren’t particularly useful for e.g. seeing what messages are emitted by the socket object or can be sent by a client. I’m sure if I need to I can manually work my way through the goban code to understand the flow of e.g. playing a game in real-time, but I’d expect the RT API to have actual documentation about which commands exist and flow in which directions.