HTTP Server from Scratch (Go)

A low-level HTTP/1.1 server and parser built from scratch using pure TCP sockets in Go — no net/http, no frameworks.

🚀 Overview

This project explores how HTTP actually works under the hood by implementing:

• TCP server using net.Listen
• Byte-level stream processing
• Custom HTTP request parsing
• Basic HTTP response handling

Instead of relying on abstractions, this project treats everything as a stream of bytes, helping you deeply understand networking fundamentals.

🧠 Key Concepts

• TCP vs UDP: Reliable, ordered data transmission
• Streams: Files and network connections as byte streams
• HTTP Protocol:
  • Request line (GET /path HTTP/1.1)
  • Headers (key-value pairs)
  • Body parsing (Content-Length, etc.)
• Parsing: Converting raw text into structured data

⚙️ How It Works

Client (curl/browser)
↓
TCP Connection
↓
Read byte stream
↓
Parse HTTP request
↓
Generate response
↓
Send back over TCP

🛠️ Run the Server

go run cmd/httpserver/main.go

In another terminal:

curl http://localhost:42069

📌 Features

• Read data byte-by-byte from TCP connections
• Line-based stream parsing using Go interfaces
• Custom HTTP request parser (start line, headers, body)
• Works with raw HTTP requests (via curl or netcat)

🎯 Learning Goals

• Understand how HTTP is built on TCP
• Learn how data is streamed and parsed
• Build intuition for protocols and system design
• Transition from “library user” → “system builder”

⚠️ Limitations

• Minimal HTTP compliance
• No concurrency optimizations
• No TLS / HTTP2 / HTTP3 support
• Designed for learning, not production

📚 References

• RFC 9110 (HTTP Semantics)
• RFC 9112 (HTTP/1.1)
• Go net package

🙌 Acknowledgment

Inspired by hands-on systems learning approaches focused on building everything from first principles.