diff --git a/CHANGELOG.md b/CHANGELOG.md
index c6dc1f3..1ac5427 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,37 @@ The MCP server (`goldenchart-mcp`) versions independently; see `mcp/`.
 
 ## [Unreleased]
 
+## [0.3.0]
+
+### Added
+- **Accessibility:** every core chart (`BarChart`, `LineChart`, `AreaChart`,
+  `PieChart`, `ScatterPlot`) now emits a fallback `<desc>` derived from its
+  data when no explicit `description` is passed — e.g. "Bar chart with 4
+  categories, values from 7 to 24." New `src/core/a11yDescribe.ts` ships the
+  per-chart-type generators; new `src/components/a11y.test.ts` covers role /
+  title / desc plumbing across charts (#119).
+- **`<ResponsiveContainer>`** — `ResizeObserver`-backed render-prop wrapper
+  so charts fill their parent. Supports `aspectRatio`, `minWidth` /
+  `minHeight` / `maxHeight`, debounced updates, and an SSR-safe `defaultSize`
+  (#120).
+- **Client-side export.** `toSvgString`, `toPng`, `downloadChart`,
+  `copyToClipboard`, plus `chartSvgFrom` / `svgPixelSize` helpers, exported
+  from the main entry. `<Surface>` accepts a new `svgRef?: Ref<SVGSVGElement>`
+  prop so consumers can grab the inner `<svg>` cleanly (#123).
+- **Themed brands.** New `ThemedBrand` shape (`{ mode?, light, dark }`),
+  `useColorScheme()` subscribing to `prefers-color-scheme`, and
+  `useResolvedBrand(brand)` combining them. `<BrandProvider>` now auto-themes;
+  plain `Brand` passes through unchanged. SSR-safe — defaults to `'light'`
+  until a browser is available (#125).
+- **Opt-in data-change transitions.** `transitions?: { enabled?, durationMs? }`
+  on `BarChart`, `LineChart`, `AreaChart`, `PieChart` — wraps the data prop
+  in `useDataTransition` so prop changes tween instead of snapping. Honours
+  `prefers-reduced-motion`. Off by default (#126).
+- **Astro Starlight docs site** under `docs-site/` with seed pages for Quick
+  start, Brand vs. vibe, BarChart reference, Responsive / Dark mode / Export
+  recipes, MCP overview, and the Vibe gallery. `npm run docs:dev` /
+  `docs:build` proxy in (#128, phase 1).
+
 ### Fixed
 - `resolveVibe` no longer returns `undefined` for an unknown preset name. A
   typo'd preset now falls back to the default vibe and logs a one-line warning
@@ -19,7 +50,7 @@ The MCP server (`goldenchart-mcp`) versions independently; see `mcp/`.
   `RoughPath`) skip degenerate geometry instead of sending Rough.js' hachure fill
   into an unbounded loop.
 
-### Added
+### Internal
 - `npm run test:coverage` (v8 provider) for a coverage report.
 - Edge-case tests for empty / single / negative / zero / non-finite data.
 
@@ -29,5 +60,6 @@ The MCP server (`goldenchart-mcp`) versions independently; see `mcp/`.
   Rough.js rendering + a Vibe engine), a headless `goldenchart/server` entry, an
   opt-in `goldenchart/fonts` subpath, and the `goldenchart-mcp` server.
 
-[Unreleased]: https://github.com/benseverndev-oss/GoldenChart/compare/v0.1.0...HEAD
+[Unreleased]: https://github.com/benseverndev-oss/GoldenChart/compare/v0.3.0...HEAD
+[0.3.0]: https://github.com/benseverndev-oss/GoldenChart/compare/v0.2.0...v0.3.0
 [0.1.0]: https://github.com/benseverndev-oss/GoldenChart/releases/tag/v0.1.0
diff --git a/mcp/package-lock.json b/mcp/package-lock.json
index 13b308b..e554b91 100644
--- a/mcp/package-lock.json
+++ b/mcp/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "goldenchart-mcp",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "goldenchart-mcp",
-      "version": "0.2.0",
+      "version": "0.3.0",
       "license": "MIT",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.18.0",
diff --git a/mcp/package.json b/mcp/package.json
index cd84c5d..e76dc46 100644
--- a/mcp/package.json
+++ b/mcp/package.json
@@ -1,6 +1,6 @@
 {
   "name": "goldenchart-mcp",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "description": "MCP server that renders GoldenChart sketchy charts and flowcharts as SVG.",
   "author": "Ben Severn",
   "repository": {
diff --git a/package-lock.json b/package-lock.json
index d8e4213..2d1aa37 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "goldenchart",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "goldenchart",
-      "version": "0.2.0",
+      "version": "0.3.0",
       "license": "MIT",
       "dependencies": {
         "d3-hierarchy": "^3.1.2",
diff --git a/package.json b/package.json
index 7c262cd..8de2631 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "goldenchart",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "description": "Hand-drawn, sketchy React charts and flowcharts. D3 does the math, Rough.js does the drawing, and a Vibe engine dials in the aesthetic.",
   "author": "Ben Severn",
   "repository": {