# Server

C++ IM TCP server with MySQL. Protocol: ../docs/protocol.md

Chat images/files: PutFile returns a temporary COS token; the client uploads bytes to COS directly.

Layout:
  src/app          startup and command registration
  src/im/handlers  heartbeat, auth, chat, contacts
  src/db           pool and SQL
  src/net          framing, sessions, kick
  sql              init.sql (new) / migrate.sql (upgrade)
  config/config.ini

Build:
  cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
  cmake --build build
  ./build/server --init-db config/config.ini   # 建库建表后启动
  ./build/server config/config.ini             # 平时启动

Auth, friends, conversations and chat require MySQL.
Set [mysql] required=1 so startup fails if the database is down.