HTTP/1.1 Server From Scratch {TypeScript}

Zero dependencies. Raw TCP sockets. Manual HTTP parsing. Because I wanted to know what app.get() actually does.

Why I Built This

I was looking to build something from scratch & not use a framework, not follow a tutorial blindly, but actually understand how the technology I use every day works under the hood.

So I chose the thing I use most and understand least: HTTP.

This server has zero dependencies. No Express. No http module. Just Node's net.Socket and Buffer management. Everything else request parsing, header validation, body streaming, routing — I wrote myself.

The server loop (serveClient):

1. Buffer data from socket into DynBuf until \r\n\r\n found
2. Cut message — extract complete request, parse into HTTPReq
3. Create body reader — readerFromReq() decides: no body, Content-Length, or chunked
4. Route to handler — match URI, return HTTPRes
5. Send response — encode headers, stream body chunks, drain request body
6. Loop — HTTP/1.1 keep-alive means same connection, next request

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Features

Feature	Status	Notes
HTTP/1.1 request parsing	Done	Manual Buffer parsing, no string conversion for URI/headers
Content-Length body streaming	Done	readerFromConnLength with decrementing remain counter
Connection keep-alive	Done	Explicit drain loop before next cutMessage
Static file serving	Done	MIME type detection from extension
True file streaming	Done	fs.createReadStream with pause/resume backpressure
Request metrics	Done	/stats endpoint
Health check	Done	/health endpoint
Echo endpoint	Done	/echo mirrors request body
Performance benchmark	Done	/benchmark vs Express using autocannon
Tests	Done	Unit tests for parser/buffer, integration tests for full server

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Performance

Local development machine (AMD Ryzen 5, 16GB RAM, plugged in):

Server	Requests/sec	Avg Latency
My implementation	29347.64	2.96ms
Express 5.2.1	16,306.19	5.51ms

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Not exactly a replacement for Express, a demonstration that HTTP/1.1 is simpler than it looks, and that overhead accumulates in frameworks

Deep Dive: True File Streaming

The problem: fs.readFileSync(filepath) loads the entire file into RAM. A 1GB video would crash a small VPS.

The solution: readerFromFileStream — a BodyReader that yields chunks without buffering the whole file.

// Before: loads entire file
body: readerFromMemory(fs.readFileSync(filepath))  // 1GB = 1GB RAM

// After: streams chunks
body: readerFromFileStream(filepath)  // ~64KB at a time

Quick Start

# 1. Clone the repo
git clone https://github.com/aryansaves/servee.git
cd http-server

# 2. Install Bun (if you don't have it)
curl -fsSL https://bun.sh/install | bash

# 3. Start the server
bun src/server.ts

# 4. Test it
bun test

# 5. Run benchmark
curl http://localhost:1234/benchmark

# 6. Available Endpoints 
curl http://localhost:1234/
curl http://localhost:1234/stats
curl http://localhost:1234/health

License

MIT — see LICENSE