Client - C, Server - S.

C>
GET wss://aternos.org/hermes/
Connection: Upgrade
Cookie: ATERNOS_SESSION=***SESSION***; ATERNOS_SERVER=***SERVER_ID***
Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits
Sec-WebSocket-Key: 294tmb+eQCF0CfWz5lvZ8A==
Sec-WebSocket-Version: 13
Upgrade: websocket
User-Agent: ...
S>
HTTP/1.1 101 Switching Protocols
Connection: Upgrade
sec-websocket-accept: TdeB4uvmMuNigQtzJuOjUzqoSkc=
upgrade: websocket

WEBSOCKET:

   # Init
S> {"type":"ready","data":"***SERVER_ID***"}
   # Start
C> {"stream":"console","type":"start"}
S> {"type":"connected"}
S> {"stream":"console","type":"started"}
   # Log
S> {"stream":"console","type":"line","data":"[23:27:07] [Server thread/INFO] [FML]: Injecting itemstacks\r"}
C> {"stream":"console","type":"command","data":"list"}
S> {"stream":"console","type":"line","data":"list\r"}
S> {"stream":"console","type":"line","data":"[23:28:28] [Server thread/INFO] [minecraft/DedicatedServer]: There are §r0§r/§r8§r players online:§r\r"}
S> {"stream":"console","type":"line","data":"[23:28:28] [Server thread/INFO] [minecraft/DedicatedServer]: \r"}
   # AdBlock detected
C> {"type":"❤"}

*** Page was refreshed
(What's the difference between stream:heap and stream:console?)

C>
GET wss://aternos.org/hermes/
Connection: Upgrade
Cookie: ATERNOS_SESSION=***SESSION***; ATERNOS_SERVER=***SERVER_ID***
Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits
Sec-WebSocket-Key: sT1PpNq/AhfY3HpIUplRIg==
Sec-WebSocket-Version: 13
Upgrade: websocket
User-Agent: ...
S>
HTTP/1.1 101 Switching Protocols
Connection: upgrade
sec-websocket-accept: 9HWtmcvFcxO8HeHQU5nXO8+R19k=
upgrade: websocket

   # Init
S> {"type":"ready","data":"cDRCfaQjQDaABPKL"}
   # Start
C> {"stream":"heap","type":"start"}
S> {"type":"connected"}
S> {"stream":"heap","type":"started"}
   # RAM usage
S> {"stream":"heap","type":"heap","data":{"usage":879372712}}
   # Changing state (lastStatus object)
S> {"type":"status","message":"{\"brand\":\"aternos\",\"status\":3,\"change\":1640978969,\"slots\":8,\"problems\":0,\"players\":0,\"playerlist\":[],\"message\":{\"text\":\"\",\"class\":\"blue\"},\"dynip\":null,\"bedrock\":false,\"host\":\"croaker.aternos.host\",\"port\":61370,\"headstarts\":null,\"ram\":0,\"lang\":\"stopping\",\"label\":\"\\u041e\\u0441\\u0442\\u0430\\u043d\\u043e\\u0432\\u043a\\u0430 ...\",\"class\":\"loading\",\"countdown\":null,\"queue\":null,\"id\":\"cDRCfaQjQDaABPKL\",\"name\":\"inc09\",\"software\":\"Forge\",\"softwareId\":\"p71sAEKNbhea4UEm\",\"type\":\"forge\",\"version\":\"1.12.2 (14.23.5.2860)\",\"deprecated\":false,\"ip\":\"inc09.aternos.me\",\"displayAddress\":\"inc09.aternos.me:61370\",\"motd\":\"IndustrialCraft 2\",\"icon\":\"fa-spinner-third fa-spin\",\"dns\":{\"type\":\"SRV\",\"domains\":[\"inc09.aternos.me\"],\"host\":\"croaker.aternos.host\",\"port\":61370,\"ip\":\"185.116.158.143\"}}"}
   # Stop
C> {"stream":"heap","type":"stop"}
S> {"stream":"heap","type":"stopped"}
S> {"type":"disconnected","data":"server"}
   # Changing state (lastStatus object)
S> {"type":"status","message":"{\"brand\":\"aternos\",\"status\":5,\"change\":1640978973,\"slots\":8,\"problems\":0,\"players\":0,\"playerlist\":[],\"message\":{\"text\":\"\",\"class\":\"blue\"},\"dynip\":null,\"bedrock\":false,\"host\":\"croaker.aternos.host\",\"port\":61370,\"headstarts\":null,\"ram\":0,\"lang\":\"saving\",\"label\":\"\\u0421\\u043e\\u0445\\u0440\\u0430\\u043d\\u0435\\u043d\\u0438\\u0435 ...\",\"class\":\"loading\",\"countdown\":null,\"queue\":null,\"id\":\"cDRCfaQjQDaABPKL\",\"name\":\"inc09\",\"software\":\"Forge\",\"softwareId\":\"p71sAEKNbhea4UEm\",\"type\":\"forge\",\"version\":\"1.12.2 (14.23.5.2860)\",\"deprecated\":false,\"ip\":\"inc09.aternos.me\",\"displayAddress\":\"inc09.aternos.me:61370\",\"motd\":\"IndustrialCraft 2\",\"icon\":\"fa-spinner-third fa-spin\",\"dns\":{\"type\":\"DEFAULT\",\"domains\":[\"inc09.aternos.me\"],\"host\":null,\"port\":null}}"}
S> {"type":"status","message":"{\"brand\":\"aternos\",\"status\":0,\"change\":1640978991,\"slots\":8,\"problems\":0,\"players\":0,\"playerlist\":[],\"message\":{\"text\":\"\",\"class\":\"blue\"},\"dynip\":null,\"bedrock\":false,\"host\":\"\",\"port\":61370,\"headstarts\":null,\"ram\":0,\"lang\":\"offline\",\"label\":\"\\u041e\\u0444\\u0444\\u043b\\u0430\\u0439\\u043d\",\"class\":\"offline\",\"countdown\":null,\"queue\":null,\"id\":\"cDRCfaQjQDaABPKL\",\"name\":\"inc09\",\"software\":\"Forge\",\"softwareId\":\"p71sAEKNbhea4UEm\",\"type\":\"forge\",\"version\":\"1.12.2 (14.23.5.2860)\",\"deprecated\":false,\"ip\":\"inc09.aternos.me\",\"displayAddress\":\"inc09.aternos.me:61370\",\"motd\":\"IndustrialCraft 2\",\"icon\":\"fa-stop-circle\",\"dns\":{\"type\":\"DEFAULT\",\"domains\":[\"inc09.aternos.me\"],\"host\":null,\"port\":null}}"}
   # Backup (why is this info here?)
S> {"type":"backup_progress","message":"{\"id\":\"\",\"progress\":0,\"action\":\"reset\",\"auto\":false,\"done\":false}"}
   # AdBlock detected
C> {"type":"❤"}