⬡ Serez Packages

serez-http

v1.0.6

HTTP/WebSocket server library for Serez-Code — Express/Flask-style API

by serezdev · published 2026-06-02

serez-http

HTTP and WebSocket server for Serez-Code — an Express/Flask-style API with routing, middleware, rate limiting and CORS, written in pure .sz. Build a REST API in a few lines and run it with sz:

import "serez-http"

const app = new App()

app.GET("/", fn(req, res) {
    let r <string, any> = ({"message", "hello from serez-http"})
    res.json(r)
})

app.GET("/user/:id", fn(req, res) {
    let r <string, any> = ({"user_id", req["params"]["id"]})
    res.json(r)
})

app.POST("/echo", fn(req, res) {
    res.json(JSON.parse(req["body"]))
})

app.listen(3000, fn() {
    out "server running on port 3000"
})

Install

sz install serez-http

The library declares the Socket and Time permissions itself — your app's serez.json does not need to add them.

Quick use

  • Routes: app.GET / app.POST / app.PUT / app.delete(path, fn(req, res) {...}). Patterns support :param segments, captured in req["params"]. (get and use are Serez-Code keywords — that's why the verbs are uppercase and middleware is addMw.)
  • Request: req is a <string, any> dict — req["method"], req["path"], req["query"], req["params"], req["body"], req["headers"], req["ip"], req["authorization"], …
  • Response: chainable — res.status(404).json(obj), plus send, header, cookie, redirect, sendfile, download.
  • Middleware: app.addMw(fn(req, res, next) {...}) — call next() to continue the chain; global error handler via app.error(fn(err, req, res) {...}).
  • Security: built-in app.rateLimit(ip, max, seconds) and a corsMiddleware(origins, methods, headers) factory.
  • WebSocket: app.ws(path, fn(req, ws) { ws.on("message", ...); ws.listen() }).
  • Single-threaded (one connection at a time) and bound to 127.0.0.1 — for deployment with external access, package it with serez-apipack.

Documentation