RFC [INSERT NUMBER HERE]: WebSocket Chat Protocol
Introduction The WebSocket Chat Protocol is designed to facilitate real-time, bidirectional communication between a client and a server over a WebSocket connection. This protocol is specifically designed for chat applications, where users can send messages to each other in real-time.
Protocol Overview The WebSocket Chat Protocol defines a simple message format that can be used to send chat messages between a client and a server. The format of a chat message is as follows:
{ "type": "message", "data": "Hello, world!", "timestamp": 1234567890 }
The "type" field indicates the type of the message, which is always "message" for chat messages. The "data" field contains the actual message text. The "timestamp" field is an optional field that can be used to indicate the time at which the message was sent.
In addition to chat messages, the protocol also defines a "user joined" message that can be sent when a new user joins the chat room:
{ "type": "user_joined", "user_id": "abc123", "display_name": "John Doe" }
The "user_id" field is a unique identifier for the user, while the "display_name" field is the user's display name.
Finally, the protocol defines a "user left" message that can be sent when a user leaves the chat room:
{ "type": "user_left", "user_id": "abc123" }
Protocol Details 3.1 Handshake
The WebSocket Chat Protocol uses the standard WebSocket handshake to establish a connection between the client and the server.
3.2 Sending Chat Messages
To send a chat message, the client sends a message in the format described above to the server. The server then broadcasts the message to all other connected clients.
3.3 User Joining
When a new user joins the chat room, the client sends a "user joined" message in the format described above to the server. The server then broadcasts the message to all other connected clients.
3.4 User Leaving
When a user leaves the chat room, the client sends a "user left" message in the format described above to the server. The server then broadcasts the message to all other connected clients.
3.5 Error Handling
If a message is received by the server that does not conform to the message format described above, the server should send an error message to the client in the following format:
{ "type": "error", "message": "Invalid message format" }
Security Considerations The WebSocket Chat Protocol is susceptible to various security threats, including but not limited to cross-site scripting (XSS) attacks, cross-site request forgery (CSRF) attacks, and denial-of-service (DoS) attacks. It is the responsibility of the server implementer to ensure that appropriate security measures are put in place to mitigate these threats.
References The WebSocket Chat Protocol is based on the WebSocket protocol, which is defined in RFC 6455. Additional information about the WebSocket protocol can be found in the WebSocket API specification.
Acknowledgements This protocol was inspired by various existing chat protocols, including but not limited to the IRC protocol, the XMPP protocol, and the Slack Real Time Messaging API. Special thanks to the developers of these protocols for their contributions to the field of real-time chat communication.