tempestweb 0.8.1

Build web apps in typed Python — one tree, a DOM renderer, two execution modes (WASM + server).

tempestweb

📚 Documentation: Português (Brasil) · English (US) — bilingual docs site (PT-BR default + EN-US), deployed to GitHub Pages.

Build web apps in typed Python. One declarative widget tree, a DOM renderer, and two execution modes that share 100% of the application code: Mode A (WASM) runs your Python in the browser via Pyodide; Mode B (server) runs it on the server (FastAPI) and talks to a thin JS client over WebSocket or SSE. Installable PWA, offline-first (service worker + IndexedDB), and WebPush are first-class — parity with tempest-react-sdk.

Sister project to tempestroid — same "one tree, multiple renderers" architecture. The renderer-agnostic engine (IR, reconciler, state, style, widgets) is shared; tempestweb adds a DOM leaf renderer (pure JavaScript, no framework, no build step, no TypeScript) and two patch transports.

Status

🚧 Early construction. See the design docs:

• docs/plan.md — full design and phase plan.
• docs/roadmap.md — phase checklist.
• docs/arquitetura.md — architecture.
• docs/contract.md — the Python↔client wire format.
• docs/agents/MANIFEST.md — parallel agent task plan.

Want runnable apps? Browse the Example Gallery (PT-BR) — 41 single-concept demos (stopwatch, forms, data table/grid, kanban, chat, theming, i18n, canvas charts, app shells, native capabilities, observability, PWA/WebPush, and a server-mode walkthrough), each running unchanged in both modes.

Building something real? Read the App architecture & best practices guide (EN) — the ideal layered structure (routes · pages · components · styles · controllers · services · storages · schemas · utils · core), mirroring tempest-fastapi-sdk, so your app doesn't rot into garbage code.

How it works

   view(app) ──build──▶ Node tree (IR)        ← shared core (vendored from tempestroid)
                            │
                          diff
                            ▼
                        [ Patch ]              insert / remove / update / reorder / replace
                       ╱          ╲
              Mode A transport   Mode B transport
              (pyodide.ffi)       (WebSocket | SSE)
                       ╲          ╱
                  client/ (pure JS): apply patches to the DOM
                  + Style→CSS + event capture                  ← same code in both modes

The application's view() never names a transport — the same examples/counter/app.py runs under --mode wasm and --mode server unchanged. Capabilities (native/: http, audio, share, geolocation, clipboard, storage, camera) are typed awaitables with the same Python API in both modes — Mode A calls the Web API in-process, Mode B proxies it over a round-trip (see docs/contract.md).

Develop

uv venv && uv pip install -e ".[dev,server,cli]"
make check          # ruff + mypy + pytest + JS (jsdom) tests

Layout

Path	What
tempest-core (dependency)	Renderer-agnostic engine — IR/reconciler/state/style/widgets (import tempest_core), extracted from tempestroid.
tempestweb/components/	Native fields + forms (EmailField, PasswordField, LoginForm, …) plus the re-exported tempest-core library — 54 Material 3 components (Card, DataTable, Tabs, Drawer, Alert, BarChart/LineChart, …).
tempestweb/transports/	The one seam between modes (base.py Protocol, wasm.py, websocket.py, sse.py).
tempestweb/server/	FastAPI + WebSocket/SSE host (Mode B).
tempestweb/native/	Web API capability adapters — http, audio, share, geo, clipboard, storage, camera (Track N).
tempestweb/observability/	Telemetry, logger, error boundary, feature flags, auth — adapter pattern (Track O).
tempestweb/pwa/	Web App Manifest + icon emitter (Track P).
tempestweb/cli/	tempestweb new/dev/build/run/sync.
client/	Pure-JS DOM renderer (incl. Canvas draw-command execution for charts), Style→CSS, event capture; pwa/ sw/ offline/ push/ native/ subdirs.
tests/fixtures/	Golden wire-format fixtures derived from the core.

Conventions

Python: double quotes, full typing (mypy --strict), Google docstrings in English, async-first. Client: plain JavaScript only — no TypeScript, no framework, no build step. See CLAUDE.md.