Charts

@backplane-labs/backplane-charts provides TimeSeriesChart, BarChart, Histogram, Heatmap, Stat, BarGauge, RadialGauge, SeriesTable, VisualizationControls and VisualizationPanel. English resources are exported as chartsEnglish for backplane.charts. Renderers load lazily. Data adapters from platform RPC responses belong to platform-ui, not this package.

Time-series x coordinates are epoch milliseconds; histogram x coordinates are numeric bucket positions. Sample values can be numbers, decimal strings, bigint or null. Canvas coordinates use finite JavaScript numbers. Original values stay in the input, hover display and data table; integer conversion loss is explicitly reported. Sorting/rendering never mutates caller data. Nulls create gaps; non-finite values are reported and omitted from plotting.

uPlot renders lines/bars. Inputs are bounded to 64 visible series and a configurable 512–20,000 point union (2,000 by default). Bucket sampling retains endpoints and local extrema, with a representative null per bucket. The UI reports sampling and partial results. It never implies that sampled data is the complete query result. The exact-value table shows the same sampled points. Use caller-owned export for the complete dataset. Series summaries operate on original data. Heatmaps display at most 10,000 cells (2,000 by default) and expose a virtualized keyboard-accessible table with selection callbacks.

Legends are keyboard-operable toggle buttons. Range selection supports dragging and explicit numeric bounds. onRangeChange does not issue queries itself. Both themes, empty/partial states, exact values and interaction are exercised in Storybook.

Stat/bar gauge, unit/stat/color controls use public pinned Grafana 13.2.3 APIs through the common theme bridge. The published package contains declarations for RadialGauge but does not export it. Our radial gauge is an SVG composition with the same public value/threshold contract; it does not import private Grafana paths. Values are accompanied by exact accessible text. Gauge min/max/threshold positions are finite display numbers, not a replacement for exact source values.

Series use the theme's chart-1…5 colors (canvas plots need concrete colors). Time axis labels adapt their precision to the visible span. controls={false} hides the series toggles and the data table when the caller renders its own legend, as Explore does.