Rational Web

Trying to make web development less irrational.

Rational Web is a Python-first, object-oriented web framework. Pages, components, services and models are Python objects; HTML, CSS and JavaScript become implementation details behind one consistent, typed, inspectable API. It is built on FastAPI, Pydantic and SQLAlchemy.

from rational import App, Button, Column, Component, Page, State, Text

app = App()


class Counter(Component):
    count = State(0)

    def increment(self):
        self.count += 1

    def render(self):
        return Column(Text(f"Count: {self.count}"), Button("Increment", on_click=self.increment))


@app.page("/")
class Home(Page):
    def render(self):
        return Counter()


if __name__ == "__main__":
    app.run()   # python app.py --dev   |   python app.py --prod

  • Server-rendered first. Every page is real HTML before any script runs. Static pages ship no JavaScript at all; interactive pages load a ~4 KiB runtime.

  • Explicit boundaries. Event handlers run on the server; only @remote methods form an HTTP API, documented in Swagger UI. Nothing is callable from the browser by accident.

  • Typed boundaries. Path parameters, event payloads and API bodies are validated from your annotations. Component prop annotations support static typing; runtime checks cover required and unexpected prop names.

  • Styles as values. Style objects compile to hashed, deduplicated CSS with themes, breakpoints and container queries.

  • Secure by default. Escaping, CSRF, session-bound events, validated payloads.

Where to start

Not sure where you should start?

Tutorial: build a guestbook

Build a guestbook step by step, from one file to a tested, deployed project.

Examples

Ten complete applications, from a CV site to a marketplace, explained file by file.

Quickstart

The five-minute version.

Learn

Guide

Background

Reference