@coxy/tcp-router

Type‑safe, encrypted TCP router for Node.js / TypeScript.
ECDH key‑exchange → AES‑256‑GCM → length‑prefix framing → middleware pipeline.

Features

• 🔐 End‑to‑end encryption – ECDH (prime256v1) handshake, per‑connection key.
• ⚡ Zero‑copy framing – [UInt32BE length][ciphertext] → no splitting/merging bugs.
• 🛣️ Middleware pipeline – similar to Koa/Express, async/await.
• 🔄 Auto‑reconnect & queue – client transparently resends messages after restart.
• 📦 Single‑file bundle – outputs minified CJS + ESM + d.ts.

Installation

npm i @coxy/tcp-router            # npm

yarn add @coxy/tcp-router            # yarn

Quick start

1 · Server

import { TcpServer } from 'tcp-secure-router'

const server = new TcpServer({
  port: 1337,
  secret: 'supersecretstring',
  whitelist: ['127.0.0.1'],
})

server.use('/echo', async (ctx) => {
  ctx.body = ctx.request           // simply echo back
})

server.listen(() => console.log('🔌 listening'))

2 · Client

import { TcpClient } from 'tcp-secure-router'

(async () => {
  const client = new TcpClient({ port: 1337, secret: 'supersecretstring' })
  await client.connect()
  const res = await client.send('/echo', { ping: 1 })
  console.log(res) // → { ping: 1 }
})()

Advanced usage

Auto‑reconnect demo

// server.ts
const srv = new TcpServer({ port: 0, secret: 's' })
const PORT = await new Promise<number>(r => srv.listen(() => r((srv.address() as any).port)))

// client.ts
const cli = new TcpClient({ port: PORT, secret: 's' })
await cli.connect()

// kill & restart server — client.send() will queue, then flush after reconnect

Scripts

| command | description | |-----------------|---------------------------| | npm run dev | ts-node watcher (nodemon) | | npm run test | Jest + ts-jest | | npm run build | tsup → minified bundle |

FAQ

Why not WebSocket?

Need pure TCP (load‑balanced behind Nginx stream, no HTTP upgrade), binary framing, and custom crypto.

How big is the bundle?

<3 KB minified (both CJS & ESM) with Terser property‑mangling.

License

MIT