Replace custom {filename, content, mimeType, encoding} params with
standard MCP resource types: EmbeddedResource for inline content and
ResourceLink for host-resolved references.
New params shape:
params: { contents: (EmbeddedResource | ResourceLink)[] }
This reuses existing MCP primitives instead of inventing new ones,
and enables hosts to show resource 'bubbles' or resolve ResourceLink
URIs via resources/read on the MCP server.
Add a new ui/download-file JSON-RPC request that allows MCP App views to
request file downloads through the host. Since MCP Apps run in sandboxed
iframes where direct downloads are blocked (allow-downloads not set),
this provides a host-mediated mechanism for file exports.
Spec changes (draft):
- Add ui/download-file request to Requests (View → Host) section
- Add downloadFile capability to HostCapabilities
- Document host behavior requirements (confirmation dialog, filename
sanitization, base64 decoding, size limits)
SDK changes:
- Add McpUiDownloadFileRequest/Result interfaces to spec.types.ts
- Add downloadFile() method to App class
- Add ondownloadfile setter to AppBridge class
- Add DOWNLOAD_FILE_METHOD constant
- Generate Zod schemas
Example:
- Add download demo to integration-server (exports JSON with server time)
- Capability check: only shows download button when host advertises
downloadFile capability
Based on developer feedback requesting file export capabilities for
visualization tools, document editors, and data analysis apps.
Update `global.css` in all `basic-server-*` examples (and `integration-server`
for consistency) to better serve as templates for AI coding agents scaffolding
new MCP Apps.
Changes:
- Use CSS custom properties (`--font-sans`, `--color-text-primary`, etc.) with
sensible fallbacks, enabling host design system integration
- Add `color-scheme: light dark` and `light-dark()` fallbacks for theme support
- Include comprehensive typography: h1-h6, body text, `code`/`pre`/`kbd`, `b`/`strong`
- Move `#server-time` styles from global CSS to component stylesheets (classes
instead of IDs for better CSS practices)
Updates E2E test selectors in `DYNAMIC_MASKS` to match the new class-based
selectors.
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Apply host-provided safe area insets as padding on main containers
across all examples. This ensures content doesn't render under
system UI elements like phone notches.
React apps use `useState` + `onhostcontextchanged` handler with
initial fetch via `getHostContext()` in `useEffect`. Vanilla JS
apps apply padding in the handler and invoke it after `connect()`.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
* Centralize example server transport logic in shared utils
Move stdio/HTTP transport handling into `server-utils.ts` so example
servers only need to call `startServer(createServer)`. Switch HTTP
transport to stateless mode and remove legacy SSE endpoints.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* Make example servers self-contained with local server-utils
Copy `server-utils.ts` into each example's `src/` directory so examples
can be used standalone without the shared directory. Updates imports
from `"../shared/server-utils.js"` to `"./src/server-utils.js"`.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* Add `integration-server` example for E2E testing
Add dedicated `integration-server` example (duplicated from
`basic-server-react`) to preserve E2E testing capabilities while
allowing `basic-server-react` to be simplified as a minimal example.
Changes:
- Add `examples/integration-server` exercising SDK communication APIs
- Update E2E tests to use `integration-server` instead of
`basic-server-react` and `basic-server-vanillajs`
- Use server name labels instead of indices for more robust test
selection
- Remove `basic-react.png` and `basic-vanillajs.png` golden snapshots
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Simplify `basic-server-*` examples
- Clarify comments
- Return plain text from `get-time` tool instead of JSON
- Remove simulated cleanup delay from `onteardown`
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
