Overview

kestrel-loom is an interactive trading-chart renderer for the browser. It draws candlestick charts, indicator panes and drawing tools onto a Canvas 2D context. Chart state, viewport math and the render loop are plain Rust, compiled to WebAssembly; only a thin façade knows what a canvas is. The indicator math comes from kestrel-chartkit.

What it covers

• Chart types: candlestick, OHLC, hollow, line, area, Heikin Ashi, Renko and footprint.
• Indicators: every indicator of kestrel-chartkit, fed incrementally. Price-unit indicators draw on the price chart, oscillators in their own pane.
• Tools: trend lines, horizontal and vertical lines, rectangles, ellipses, Fibonacci retracements and text labels, with hit testing, selection, snapping and undo/redo.
• Interaction: wheel, trackpad and pinch told apart, kinetic glide, a time scrollbar, crosshair, log and linear price scale, light and dark theme.
• Scenes: kestrel-chartkit’s viz::scene model (zones, pivots, profiles) rendered onto the canvas.

Where it stops

No indicator math, no strategies, no backtesting, no persistence, no data feed and no backend. kestrel-loom draws what it is given; where the bars come from is your application’s business.

Status

Alpha. The chart runs and is exercised in a browser, but the API is not stable. It is not published to crates.io or npm: you build it from the repository. The demo on this site runs the current build.

License

Business Source License 1.1 (BUSL-1.1), the same terms as kestrel-chartkit: free for non-commercial use including production, commercial use requires a license from the Licensor, and the work converts to Apache-2.0 four years after publication. The LICENSE file is authoritative.

How the docs are organised

• Getting started: build the package and put a first chart on a page.
• Guides: indicators and panes, drawing tools.
• Concepts: the browser-free core and the session-continuous time axis.
• Reference: the grouped JavaScript API.