Pyrite

Code websites in Python 3, for JavaScript and CSS haters.

Pyrite is a small, dependency-free starting point: compose Python components, return a page, and serve HTML with built-in responsive styling. Requires Python 3.10+.

Run the example

python3 example.py

Open http://127.0.0.1:8000. The example is Pyrite's first website: a homepage with a code/output comparison, quickstart, expandable FAQ, and a component guide at /guide. Try /playground for a Python-powered calculator. Its application source uses only Python components. No installation is required when running from this repository.

Build a page

from pyrite import App, Column, Heading, Page, Text

app = App()

@app.page("/")
def home():
    return Page(
        Column(Heading("Hello, Pyrite."), Text("Just Python.")),
        title="My website",
    )

if __name__ == "__main__":
    app.run()

Available components: Heading, Text, Column, Row, Card, Link, and Button, Section, Nav, Code, and Details. Nest components directly. Section(..., id="start") creates an anchor target. Code(source, label="Python") displays escaped source. Details(question, ...) provides a native expandable answer. Heading accepts level=1 through 6. Link(label, href) and Button(label, href) navigate to another URL. Text and HTML attributes are escaped automatically.

Register exact paths with @app.page("/about"). Handlers take no arguments and return a Page. Query strings do not affect route matching. Page accepts title and language; app.run accepts host and port.

Current scope

This version serves server-rendered pages with native GET forms and JSON POST callbacks through LiveForm and Chat. It does not include server sessions, token streaming, live reload, or a production server. The built-in HTTP server is for local development. Styling is supplied by Pyrite; applications do not need CSS files or JavaScript tooling.

Styling in Python

Edit the root styles.py to change the example website's shared theme. Restart the server after editing. Theme supports six-digit hex colors, sans, serif, or mono fonts, page width, corner radius, and spacing. Apply a theme to any page:

from pyrite import Theme

theme = Theme(background="#111820", text="#eef3f8", heading_font="sans")
page = Page(Heading("Your style."), theme=theme)

Forms without JavaScript

from pyrite import Form, Input, Submit, query

@app.page("/hello")
def hello():
    return Page(Column(
        Form(Input("name", "Your name", value=query("name")), Submit("Say hello")),
        Text(f"Hello, {query('name', 'world')}!"),
    ))

Slider(name, label, value=5, minimum=1, maximum=10) and Select(name, label, {"value": "Label"}, value="value") also work in forms. Submission reloads the page; query reads request-local URL parameters. GET forms are for read-only calculations and searches; their values appear in the URL.

Try Pyrite in Browser

Visit /try to edit Python and render a real Page without installing Python. Assign your result to page; do not call app.run(). The editor loads Pyodide from jsDelivr and runs code in a disposable Web Worker, with a 10-second execution limit and an isolated preview. First download can take up to two minutes. Code is not executed on the application server. Browser networking follows CORS rules; the standard-library HTTP client below is for server-side Python.

Images and motion

from pyrite import Image, Motion
from styles import hero_image

banner = Motion(Image(hero_image, "Mountain landscape"), effect="rise")

Choose rise, fade, or float. In styles.py, set motion=False to disable component animations, or change motion_duration (100–5000 milliseconds) for entrances. Reduced-motion browser preferences disable animations automatically. Theme(background_image="https://example.com/background.jpg") attaches a page background. Image accepts relative or HTTP(S) URLs and requires alt text. External images load directly from their host; local file serving is not included.

Requests and changing API data

from pyrite import requests

data = requests.get(
    "https://api.mymemory.translated.net/get",
    params={"q": "Good morning", "langpair": "en|uk"},
).json()

# For an API you control, with the authentication it requires:
# requests.post("https://your-api.example/items", json={"name": "New"})
# requests.put("https://your-api.example/items/1", json={"name": "Changed"})
# requests.delete("https://your-api.example/items/1")

The dependency-free client supports get, post, put, and delete, optional headers, JSON bodies, query parameters, and a timeout (8 seconds by default). Responses expose status_code, text, and json(). Catch requests.RequestError for HTTP/network/decoding failures. Responses are limited to 1 MiB. Supply trusted URLs in application code; do not forward visitor-provided URLs to this client. GET page handlers should only read data. POST actions can make remote writes; add application authentication and authorization before exposing private data or operations. Pyrite's local development server does not provide authentication.

/translate demonstrates input, a real free MyMemory request, and updated page content. No API key required; availability, translation quality, and quotas depend on MyMemory. Submitted text is sent to that service.

Corners and gradients

from pyrite import Gradient, Theme

theme = Theme(
    radius=20,              # Panels, code blocks, images, details
    button_radius=999,      # Pill buttons; 0 gives square corners
    input_radius=12,        # Inputs and dropdowns
    gradient=Gradient(
        colors=("#101923", "#214a42", "#17283d"),
        angle=120,
        moving=True,
        duration=14,       # Seconds per cycle
    ),
)

button_radius and input_radius inherit radius when omitted. Gradients accept 2–8 hex colors; set moving=False for a static gradient or gradient=None for the usual background. A fixed background layer animates independently of page length. motion=False or the browser's reduced-motion preference stops its movement. The gradient layer sits over a background image when both are configured.

In-page requests and chat

from pyrite import App, Chat, Page

app = App()

@app.action("/api/reply")
def reply(data):
    message = data["message"]
    history = data.get("history", [])
    # Call a model here with pyrite.requests; keep API keys on the server.
    return {"reply": "You said: " + message}

@app.page("/")
def home():
    return Page(Chat(action="/api/reply"))

Visit /chat for a working local rule-based chatbot and a live translation form. Chat sends {message, history} and displays reply without a page reload. History stays in this page's browser memory (last 20 messages), is sent with each request, and clears on reload. It is untrusted input; validate it in callbacks. This is completed-response chat, not token streaming. The demo uses no AI service.

For other interfaces, use LiveForm(Input(...), Submit(...), action="/api/action") and return {"text": "Updated result"} from the action. All field values arrive as strings. Pyrite supplies the JavaScript, pending state, errors, 30-second client timeout, and safe text rendering. The callback can use requests to reach external APIs without exposing credentials to the browser. Aborting a request does not cancel Python work already running.

Actions accept JSON objects up to 16 KiB and reject cross-origin browser requests. These checks do not authenticate users. Use application validation and authorization for sensitive actions. Live components require JavaScript; ordinary pages and GET forms continue working without it. Browser playground previews remain isolated and cannot call server actions.

Tests

python3 -m unittest discover -s tests -v