Changelog

The canonical, complete history lives in the repository's CHANGELOG.md. It follows Keep a Changelog; semantic-versioning compatibility becomes the firm contract at 1.0. Before 1.0, a minor release can contain breaking changes.

• The fluent public Figure builder has been removed. Build with declarative chart and component factories; use Chart for display, export, streaming, and readout. Chart.figure() remains an advanced internal-engine escape hatch.
• Mark style= now uses paint-specific CSS: stroke for line-like marks and fill for filled marks. The legacy factory color= argument remains, but color is not an alias inside a style dictionary.
• The former MarkStyle/mark_style() state-styling surface is removed. Framework applications should derive ordinary props and styles from application state.
• PNG export defaults to the browser-free native renderer. Select Engine.chromium for browser CSS/WebGL fidelity.
• Chromium PNG accepts custom_css=. Native PNG rejects author CSS; complete chart-level tokens can still resolve through renderable chart styles.
• Browser executable parameters were replaced by automatic discovery or the XY_BROWSER environment variable.

The current alpha line added the compact accessible toolbar and editable lasso selection, the versioned binary frame transport, declarative statistical and density families, facets, live Chart.append()/pick()/select_range(), browser-free native PNG, pure SVG export, CSS-compiled mark styling, and the experimental xy.pyplot compatibility layer.

The Unreleased polar expansion adds heatmap, contour, and error-bar marks; partial sectors, holes/data-space origins, categorical theta, log/symlog radius, and polygonal grids; and matching pyplot theta/r-origin controls. Protocol v12 prevents an older client from silently interpreting that geometry as the previous full-circle surface.

Outlined radar charts now render reliably: radar_chart(fill=False) translates area stroke settings into the corresponding line props, including color, width, opacity, curve, and dash.

Default tooltips now lead with a named series and speak polar coordinates on polar charts: θ values reuse authored tick labels or the axis unit, and radial values are labeled r instead of appearing as Cartesian x/y rows.

Read Chart methods, Customize Each Part, and Limitations and alpha status when upgrading code across alpha releases.