| Filename | Latest commit message | Latest commit date |
|---|---|---|
494c73e7caAdd 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. |
||
| .. | ||
| src | ||
| .gitignore | ||
| main.ts | ||
| mcp-app.html | ||
| package.json | ||
| README.md | ||
| server.ts | ||
| tsconfig.json | ||
| tsconfig.server.json | ||
| vite.config.ts | ||
Example: Integration Test Server
An MCP App example used for E2E integration testing.
Overview
This example demonstrates all App SDK communication APIs and is used by the E2E test suite to verify host-app interactions:
- Tool registration with a linked UI resource
- React UI using the
useApp()hook - App communication APIs:
callServerTool,sendMessage,sendLog,openLink
Key Files
server.ts- MCP server with tool and resource registrationmcp-app.html/src/mcp-app.tsx- React UI usinguseApp()hook
Getting Started
npm install
npm run dev
How It Works
- The server registers a
get-timetool with metadata linking it to a UI HTML resource (ui://get-time/mcp-app.html). - When the tool is invoked, the Host renders the UI from the resource.
- The UI uses the MCP App SDK API to communicate with the host and call server tools.