Examples

Each example is a complete project with file layout, source, build commands, and run notes. Pick one near your problem shape; every page links to the relevant module docs at the bottom.

By host environment

• Frontend — todo list with reactive DOM updates. Vite + vanilla DOM. Output is static.
• Backend — WebSocket server with per-connection signals and an SSE stats endpoint. Node 18+.
• Edge — Durable Object rate limiter with when blocks for once-per-window alerts. Cloudflare Workers.

IoT and hardware

• Multi-plant auto waterer — moisture sensors + pumps + tank-level sensor with when-block edge alerts. Real ADS1115 + Pi GPIO, plus a simulator that runs on any host.
• GPIO state over HTTP + SSE — button + LED exposed as a live web surface. One effect { } block writes the LED AND broadcasts to every SSE client.

Voice and ML

• Voice assistant — wake-word → STT → LLM → TTS → speaker, with one grammar-constrained tool that flips a real GPIO LED. ~35 lines.
• Voice assistant + MCP — same loop, bridged to a real MCP server (Context7 for live library docs, plus the official memory server for persistent recall). One mcp.connect() flattens every tool into the bot.
• Smart camera — V4L2 capture → motion detector → save a JPEG snapshot whenever motion fires. Three Parabun modules glued by an async iterator.

Data engineering

• Streaming ETL — 10M-element |> pipeline with SIMD primitives. ~5-6× over .map().reduce(). Cross-runtime.
• Parquet ETL — synthesize 50K events, write Parquet with bloom filters, demonstrate row-group skip on targeted queries. Cross-runtime.

Setup

# Install the @para/* packages your code uses, e.g.:
npm install @para/signals @para/parallel @para/arrow

# .pts / .pjs files compile with parabun build:
parabun build src/main.pts --outfile dist/main.js

Compiled output is standard JavaScript with import "@para/foo" statements — bundlers resolve those through node_modules with no additional config.

Build targets

Project	parabun build target	Runner
Frontend / browser	--target browser	Vite, esbuild, etc.
Backend / Node	--target node	node dist/...
Edge / Workers	--target browser	Wrangler
IoT / voice / vision	(Parabun-only)	parabun src/...
Data ETL	any target	any host