local-chat-backend

Go example server for a LOCO-style local chat backend.

This is intentionally small and dependency-free:

• TCP server on 127.0.0.1:5050
• HTTP diagnostics on 127.0.0.1:8080
• LOCO-style frame:
  • 4B id
  • 2B status
  • 11B method
  • 1B type
  • 4B body length
  • BSON body

Run

cd local-chat-backend
go run ./cmd/local-chat-backend

HTTP diagnostics

Invoke-RestMethod http://127.0.0.1:8080/healthz
Invoke-RestMethod http://127.0.0.1:8080/sessions

Chat messages do not go through HTTP. A client sends a TCP WRITE packet, then the server responds to that request and broadcasts a TCP MSG push packet to connected sessions.

Supported LOCO methods

• PING
• CHECKIN
• LOGINLIST
• LCHATLIST
• CHATINFO
• CHATONROOM
• WRITE

Important

This sample reads and writes the plain LOCO packet structure. It does not implement the Kakao V2SL RSA/AES-GCM handshake.

For a real private local server, change the client to either:

1. use plain local TCP while testing, or
2. use your own RSA public key in the client and implement the matching V2SL handshake in this server with your private key.