Release Notes

0.3.0

viewport replaced with containerDimensions — The viewport property in host context has been replaced with containerDimensions, which provides a clearer distinction between fixed dimensions and maximum constraints. The new type allows specifying either height or maxHeight, and either width or maxWidth by @martinalong in #153

Video resource server — Demonstrates video resource handling with proper mimeType declarations by @antonpk1 in #175
Sheet music server — Interactive sheet music notation example by @jonathanhefner in #196

npm start alias — Added npm start as alias for npm run examples:start by @jonathanhefner in #183
Examples cleanup — Improved consistency across example servers by @jonathanhefner in #182
Documentation fixes — Fixed tsc command in docs to use tsconfig.json by @blackgirlbytes in #188

Move prettier to dev dependency — Fixed incorrect dependency classification by @niclim in #179
Fix build errors in examples — Resolved build issues across example servers by @jonathanhefner in #180

Full Changelog: https://github.com/modelcontextprotocol/ext-apps/compare/v0.2.2...v0.3.0

Changes from 0.1.x to 0.2.2.

Server helpers — New registerAppTool() and registerAppResource() simplify server setup with proper type safety. connect() now defaults to PostMessageTransport(window.parent), enabling simpler initialization with just await app.connect() by @ochafik in #165
Tool visibility control — New visibility array field controls whether tools are visible to the agent, apps, or both. Restructured _meta format from flat "ui/resourceUri" to nested _meta.ui.resourceUri by @jonathanhefner in #131
Host-provided theming — Apps receive 36 standardized CSS variables for colors, typography, and spacing via styles.variables, enabling visual consistency with the host by @martinalong in #127
Display mode requests — Apps can request display mode changes (e.g., fullscreen) via requestDisplayMode, with hosts able to accept or reject by @martinalong in #152
Custom fonts support — Apps can receive custom fonts via styles.css.fonts and apply them using applyHostFonts() or useHostFonts() helpers by @martinalong in #159

MCP SDK as peer dependency — Consumers control their SDK version, reducing duplication by @ochafik in #168
React as peer dependency — Supports React 17, 18, and 19 by @ochafik in #164
Renamed request methods — Removed send prefix: openLink() and teardownResource(). Deprecated aliases maintained by @ochafik in #161
Optional Client in AppBridge — Enables custom forwarding scenarios without direct MCP client access by @ochafik in #146
Zod v3 and v4 support — Bring your own Zod by @alpic-ai in #49
Zod schemas now version-agnostic — Generated schemas work with both Zod 3.25+ and v4, using z.object().passthrough() instead of v4-only z.looseObject() by @ochafik in #178

Windows compatibility — Bun as optional dependency with automatic setup, cross-env for examples. Just run npm install by @ochafik in #145
Widened @oven/bun-* version range — Lowered the minimum from ^1.3.4 to ^1.2.21, helping contributors whose registries may not have the latest packages by @ochafik in #176
SSE transport support — All examples now support both stdio and HTTP transports with SSE endpoints for older clients by @ochafik in #136
Playwright E2E tests — Screenshot golden testing across all 9 example servers with parallel execution (~28s) by @ochafik in #115
hostContext exposure — Access hostContext directly from the App class by @ochafik in #139

Responsive UIs — Fixed narrow viewport handling for mobile and sidebar experiences by @ochafik in #135
Sandbox notification fix — Fixed sandbox-ready notification name to match implementation by @ochafik in #160
Fixed non-UI tool registration — Use server.registerTool for tools without UI and fix missing imports across examples by @ochafik in #173

Full Changelog: https://github.com/modelcontextprotocol/ext-apps/compare/v0.1.1...v0.2.2