The Obby protocol consists of commands sent between a client and a server. There is one command per line, possibly with a colon and some parameters.

When a client connects to a server, the server sends:

obby_welcome:8
net6_encryption:0

The obby_welcome command specifies what protocol version the server uses. The net6_encryption means that the server wants an encrypted connection. The "0" parameter means that the server requests encryption; the client would use "1".

The client responds:

net6_encryption_ok

The server sends:

net6_encryption_begin

At this point, the client starts a TLS handshake. After that, the connection is encrypted.