HTTPServer

A lightweight, educational HTTP server built from scratch in Swift using only the standard library and Darwin socket APIs — no external frameworks.

This project implements a minimal yet functional HTTP server that serves a paginated user list API with filtering, designed specifically for learning low-level networking, HTTP protocol handling, and concurrency in Swift.

Features
TCP socket server (socket, bind, listen, accept)
HTTP/1.1 request parsing (method, path, query params, headers)
Pagination (page, size)
Filtering (status=active or inactive)
Thread-safe in-memory user store (actor)
Concurrent client handling (DispatchQueue)
JSON encoding/decoding (Codable)
Error handling (400, 404, 500)
Request/response logging
Command-line executable

---

Project Layout:

HTTPServer/
├── HTTPServer/
│   ├── APIResponse.swift
│   ├── HTTPRequest.swift
│   ├── HTTPResponse.swift
│   ├── Metadata.swift
│   ├── User.swift
│   ├── HTTPServer.swift
│   ├── Logger.swift
│   ├── main.swift
│   ├── RequestHandler.swift
│   └── UserStore.swift

API Endpoint:

GET /users?page={page}&size={size}&status={status}

Response Format:

{
  "metadata": {
    "currentPage": 1,
    "totalPages": 5,
    "pageSize": 10
  },
  "users": [
    { "id": "u1", "name": "Orko 1", "status": "inactive" },
    { "id": "u2", "name": "Molly 2", "status": "active" }
  ]
}

Root Endpoint:

curl http://localhost:8080/

{ "message": "Welcome to the User API" }

Query Parameters:

Param	Type	Default	Description
page	Int	1	Current page
size	Int	10	Items per page
status	String	nil	Filter: active or inactive

Example Requests:

curl "http://localhost:8080/users?page=1&size=5"
curl "http://localhost:8080/users?page=2&size=10&status=active"

Sample Console Output:

[2025-11-03 14:22:10] Server started on port 8080
[2025-11-03 14:22:15] GET /users?page=1&size=10&status=active → 200 OK
[2025-11-03 14:22:18] GET /invalid → 404 Not Found
[2025-11-03 14:22:20] Invalid query: page=-1 → 400 Bad Request

Build and Run

Prerequisites:

• Xcode 26
• macOS 26 or later

Compile

Navigate to the HTTPServer that is adjacent to the HTTPServer.xcodeproj in the folder structure. Then run:

swiftc *.swift -o httpserver

Run

./httpserver

Test

# Basic request
curl "http://localhost:8080/users?page=1&size=5"

# Filtered request
curl "http://localhost:8080/users?page=1&size=10&status=active"

# Welcome page
curl http://localhost:8080/

# Error cases
curl "http://localhost:8080/invalid"        # 404
curl "http://localhost:8080/users?page=-1"  # 400

Stop

Press Ctrl + C

License

Proprietary Software

© 2025 SarahUniverse

This software and its source code are the exclusive property of SarahUniverse. No part of this software may be reproduced, distributed, or transmitted in any form or by any means without prior written permission.