Re-use SSH connection for SFTP

Can I open a single SSH connection to run commands over, and have an SFTP session over the same connection, too? My application needs both and I don't like opening and authenticating two separate network connections to the same host for that.

I've tried to find out a bit about the inner workings of SSH but didn't get too far. I know that an SSH subsystem is just a server-side alias for a preconfigured command like "sftp-server". And I know that sftp-server speaks its own protocol to a client (albeit similar to the packet structure of SSH itself, which seems to cause performance issues due to double-encapsulation) over a "channel" (?) through the SSH connection. And I believe that there can be multiple channels in one SSH connection. That makes me wonder if there can be, say, a terminal and two SFTP sessions on a single SSH connection.

Iniziare esaminando le API di connessione SSH e dei canali della libreria, prestando attenzione ai casi d'uso della sessione SFTP e del terminale descritti qui. Determinare se una connessione può supportare più canali e sessioni SFTP, quindi documentare o esporre un approccio supportato, con copertura per lo scenario con il comando, il terminale e due sessioni SFTP.