Web Apps & APIs

Host websites, APIs and web apps: bind the right port, serve pages, and put them on a domain.

Your first web app

The two rules every web app on Falix must follow — read the port from SERVER_PORT and bind 0.0.0.0 — plus where to find your public address and how to test it in a browser.

Host a static website

Put plain HTML, CSS, and JavaScript online with zero code — deploy the Static Website template onto a PHP Web Server application, then drop your files into public/.

BeginnerTemplate

Build an Express website + API

Serve static pages and JSON API routes from one Node.js server with the Express Website + API template — walk the starter code, then add your own route.

BeginnerTemplate

Host a Next.js site

Serve a Next.js app on the Node.js application with standalone output, a build-on-install step, and a tiny launcher — the exact recipe, and why each piece has to be there.

IntermediateTemplate

Build a Flask web app

Run a Python web app on Falix with the Flask template — an HTML route plus a JSON API route in app.py, installed from requirements.txt on start, then add a route of your own.

BeginnerTemplate

Build a FastAPI app

Run a typed Python API on Falix — validation and an interactive docs page come free from your type hints, with uvicorn serving it on SERVER_PORT.

Host a PHP website

Run PHP on Falix's PHP Web Server application — nginx and PHP-FPM under supervisord, pretty URLs through a front controller, and how to bring in Composer packages.

IntermediateTemplate

Domains and HTTPS

Take a web app from an ugly address:port to a real domain with automatic SSL, using the Network page's Ports, Falix subdomains, and Reverse Proxy tabs.

Real-time apps with WebSockets

Serve HTTP and a WebSocket from your one public port by attaching a WebSocket server to the HTTP server that's already listening — the pattern that fits Falix exactly.

Designing a small REST API

Routes, HTTP status codes, and input validation for a clean Express API on Falix — the shape most bot dashboards, mobile backends, and side projects actually need, verified end to end.

Sessions, JWT & passwords

The honest minimum for logging users into your app — hash passwords with bcrypt, choose between cookie sessions and JWTs, and store sessions so they survive a restart. Verified end to end on the Node.js application.

Handling file uploads

Accept file uploads in an Express app with multer — save to disk, cap the size, reject the wrong types — plus the honest truth about disk on a Falix server and where big files really belong.

CORS errors explained

Why the browser blocks your API call with a CORS error, what the preflight request actually is, and the exact one-line fix with the cors package — reproduced with real requests.

Rate limiting your API

Stop abuse and runaway loops with express-rate-limit — return a clean 429 after N requests, choose sensible windows, and move the counter to Redis when one process isn't enough. Verified with a request loop.

Server-rendered sites with EJS

Build a multi-page site with real HTML templates — a shared layout, reusable partials, and data from your server — using EJS on Express, no frontend framework and no build step. Verified render included.

Build and host a React SPA

Build a Vite + React single-page app on the server and serve it from Express — the build-on-install step, static asset serving, and the SPA fallback that makes client-side routing work. Verified in-container.

IntermediateTemplate

Real-time apps with Socket.IO

Socket.IO gives you rooms, events, auto-reconnect, and fallbacks on top of WebSockets — the higher-level option for chat and live features. A verified server-plus-client round-trip, and an honest comparison with plain ws.

Live updates with Server-Sent Events

When the server just needs to push updates one way — live scores, progress bars, notifications — SSE is simpler than WebSockets: a plain HTTP stream the browser reconnects for you. Verified with curl -N.

Static site generators (Eleventy & Astro)

Turn Markdown and templates into a fast static site with Eleventy or Astro, then host the built output on Falix — the build-then-serve workflow, verified, with the build-locally-upload path emphasized honestly.