Please read my Facebook post introducing the features of the new version 3.7 protocol of ParrotTalk, now a 5 message handshake, 3 messages like TLS 1.3 and an initial 2 message negotiation to determine which version of the protocol to use. My release of the Squeak/Pharo implementation which is capable of supporting both v3.6 and v3.7 in the same SessionAgent, spawning Sessions with either version, based on the negotiation. The Java version at https://github.com/CallistoHouseLtd/ParrotTalk can only talk v3.6 right now. The interesting feature of the Squeak/Pharo implementation is that it supports version negotiation for either version. Tests are all green.