feat(mcp): add support for MCP Apps#15041
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lgrammel
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May 7, 2026
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| import { useEffect, useState } from 'react'; | |||
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files name are not conform to our standard
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also what would be the best possible name for this class?
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hmm i thought MCPAppRenderer might be appropriate since it's only specific to that for now
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then shouldnt this be mcp-app-renderer.tsx
lgrammel
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May 7, 2026
lgrammel
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May 7, 2026
lgrammel
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May 7, 2026
gr2m
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May 7, 2026
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Background
#12053
#11651
The MCP spec allows connecting hosts to MCP apps (which offer a specialised UI along with tool calls) https://apps.extensions.modelcontextprotocol.io/api/index.html
Summary
mcp-client.tsin the example creates a client withmcpAppClientCapabilities. That capability is added inpackages/mcp/src/tool/mcp-apps.tsclient.listTools(), thensplitMCPAppTools(), then passes only modelVisible tools to streamText. This keeps app-only tools away from the modelpackages/mcp/src/tool/mcp-client.tsnow preserves MCP App metadata on converted AI SDK tools undermetadata.mcp.apppage.tsxpasses tool UI parts toMCPAppRenderer. The renderer reads part.callProviderMetadata.mcp.app, loads the resource through the host route, then renders it via a sandbox iframepackages/react/src/mcp-apps/bridge.tshandles ui/initialize, tool input/result notifications, tools/call, resources/read, display mode requests, logs etc. this exists for the host to communicate with the mcp serverManual Verification
http://localhost:3000/chat/mcp-appsChecklist
pnpm changesetin the project root)Related Issues
fixes #11651 and #12053