Introduction

@ardinsys/contour is a canvas-first charting engine for financial time series. It keeps rendering, zooming, and streaming data responsive while staying small and framework agnostic.

Design goals

• Fast on real data: tuned for large intraday feeds, with debounced drawing and sensible defaults for trading UX (crosshair, volume, zoom/pan).
• Predictable API: explicit stepSize, index-based bars that collapse calendar gaps, clear input ownership, and explicit lifecycle methods (setData, updateData, events) so you always know when state changes.
• Extensible: register custom controllers, indicators, plugins, and drawing tools without forking the library – expose formatters, themes, and locale labels for branding.
• Minimal surface area: no runtime dependencies, ES module output, and primitive DOM requirements (a single container element).

What you can build

• Real-time price charts with candlesticks, bars, or line/area series.
• Multi-pane layouts with overlay or paneled indicators.
• Interactive drawings such as trendlines, horizontal lines, rectangles, and text.
• Themed experiences that respect light/dark toggles and locale-aware labels.
• Custom controllers that map proprietary data onto the shared time axis.

What this library is not

• A hosted charting platform or collaboration service – persistence hooks are provided, but storage belongs to your application.
• A full UI kit – you bring surrounding controls and state management.