WebSocket Protocol Implementation

Coming Soon

This lesson will guide you through implementing the WebSocket protocol from scratch in pure Erlang. You’ll learn how to:

• Implement WebSocket handshake negotiation
• Parse and generate WebSocket frames
• Handle different frame types (text, binary, ping, pong, close)
• Implement masking and unmasking for security
• Build real-time bidirectional communication

What You’ll Build

By the end of this lesson, you’ll have implemented:

• Complete WebSocket handshake handling
• WebSocket frame parsing and generation
• Support for all WebSocket frame types
• Connection upgrade from HTTP to WebSocket
• Real-time communication foundation for your chat server

Key Concepts Preview

% WebSocket handshake
generate_accept_key(Key) ->
    Magic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11",
    Hash = crypto:hash(sha, Key ++ Magic),
    base64:encode(Hash).

% Frame parsing
parse_frame(<<FIN:1, _RSV:3, Opcode:4, Mask:1, PayloadLen:7, Rest/binary>>) ->
    parse_payload(FIN, Opcode, Mask, PayloadLen, Rest).

This lesson builds on the HTTP request handling from Lesson 14 and prepares you for building the chat server core in Lesson 16.

This lesson is currently under development. Check back soon for the complete content!