Summary

Implements MCP Apps support for `static_map_image_tool`, enabling interactive map preview in compatible hosts (Claude Desktop, VS Code Insiders, etc.).

Screenshots

Inline view (with fullscreen button):

Fullscreen view:

Changes

Dependencies

• Add `@modelcontextprotocol/ext-apps@^1.0.1`
• Upgrade `@modelcontextprotocol/sdk` to `^1.26.0` with patch softening validation errors to warnings

Tool Enhancement

• Refactored `StaticMapImageTool` to return URL directly instead of fetching and base64-encoding
• Added `meta` property with `resourceUri` and CSP configuration
• Added `viewUUID` to tool response `_meta` so the host routes the result to the correct UI panel
• Maintains backward compatibility with MCP-UI via `createUIResource()`

MCP Apps UI

• Created `StaticMapUIResource` serving interactive HTML via `ui://mapbox/static-map/index.html`
• Inline MCP Apps protocol client (avoids CSP issues with external imports)
• Sends `ui/notifications/size-changed` after image loads to fit the panel to the image height
• Fullscreen toggle button (shown when host supports fullscreen mode)
• Handles `ui/notifications/host-context-changed` to re-fit on returning from fullscreen

Infrastructure

• Enhanced `BaseTool` with `meta` property for MCP Apps metadata
• Updated `index.ts` to use `registerAppResource` for UI resources (with `as any` cast — the type incorrectly requires `_meta` at registration time, but per the ext-apps example CSP belongs only in the response)
• Added `StaticMapUIResource` to resource registry

Why URL instead of base64?

1. No server-side fetching: Eliminates unnecessary API calls
2. MCP Apps compatibility: URL fetched by client with proper CSP
3. Better performance: Avoids encoding/decoding overhead

Testing

• ✅ All 610 tests passing
• ✅ Updated tests to expect URL text content
• ✅ Lint and format clean
• ✅ Verified in Claude Desktop (inline + fullscreen)

Related

• Companion to mcp-devkit-server PR #62
• Follows MCP Apps specification: https://blog.modelcontextprotocol.io/posts/2026-01-26-mcp-apps/