Chatto

A chat server and client that uses Google Protobuf over websocket for communication, written in C#.

Protocol

Defined in the protobuf definition.

Connection and handshake

• Client connects to server websocket
• Client sends a Join message with name, room, etc.
• Server sends a JoinResponse message
  • If the join is successful, it will contain a JoinResponseSuccessful message, with the room's information
  • Otherwise, will contain an Error enum

When another user sends a message:

• Server will emit a MessageFromServer message
  • It will contain a Chat message with the sender's info, and time in unix epoch ticks
• The client should reply with a MessageToServer
  • It should contain a ReadReciept message with required information
  • It should contain a time value in unix epoch ticks

When another user does an action other than chat (eg. join or leave)

• Server will emit a MessageFromServer message
  • It will contain a UserAction message, and time
  • The action is shown in the UserAction.action_type field
  • It will be of type enum ActionType

If there is an error

• Server will emit a MessageFromServer message
  • It will contain an Error enum, denoting the type
  • will contain time

Broadcast from server

• Server will emit a MessageServer message
  • will contain a string server_broadcast and time