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MCP Apps

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Render interactive MCP UI widgets (MCP Apps) inline in the kagent chat and test them from the dashboard.
MCP Apps are MCP tools that ship an interactive user interface with their results. Instead of returning plain JSON, an MCP server can attach an HTML/UI resource to a tool using the MCP Apps extension (@modelcontextprotocol/ext-apps). When an agent calls such a tool, kagent renders a live widget — a form, board, chart, or dashboard — directly in the chat.
How it works

An MCP server advertises an app by setting _meta.ui.resourceUri on a tool in its configuration (ui://server-everything/weather-dashboard). kagent detects this metadata on the MCP server automatically: no extra kagent configuration is needed.
  • Inline rendering. When the agent calls an MCP App tool, the chat renders the app’s UI resource in a sandboxed frame inside the chat message, in addition to the usual tool-call details.
  • Two-way messaging. The app can send messages on the user’s behalf, and kagent proxies the app’s resource reads and tool calls back to the originating MCP server. This lets a widget update itself in place, for example by re-calling its own tool.
  • Model-result compaction. Rich UI payloads stay in the chat history for rendering, but kagent compacts what is sent back to the model, avoiding token bloat and redundant tool churn. A tool’s _meta.ui.visibility controls whether results are app-only or also visible to the model.
Discover and test apps in the dashboard

The MCP servers page in the kagent dashboard lists each server’s MCP Apps alongside its regular tools. The server row shows separate counts (for example, “5 tools · 1 app”), and apps are marked with a window icon.
Clicking an app opens a standalone testing page where you can invoke the tool with JSON arguments and preview the rendered widget — without going through an agent chat. This is useful when developing your own MCP Apps.
Try it out

The Server Everything reference MCP server exposes a show-weather-dashboard MCP App. Connect it to kagent with a RemoteMCPServer:
apiVersion: kagent.dev/v1alpha2
kind: RemoteMCPServer
metadata:
  name: server-everything
  namespace: kagent
spec:
  url: "https://servereverything.dev/mcp"
  protocol: STREAMABLE_HTTP
  timeout: 30s
  sseReadTimeout: 5m0s
  description: "Server Everything reference MCP server with an interactive weather dashboard MCP App"
Then reference the tool from an agent like any other MCP tool:
tools:
  - type: McpServer
    mcpServer:
      apiGroup: kagent.dev
      kind: RemoteMCPServer
      name: server-everything
      toolNames:
        - show-weather-dashboard
Open the agent in the kagent UI and ask: “show the weather dashboard”. The dashboard renders inline in the chat and keeps itself updated in place.
A complete example, including a demo agent, is available in the kagent repository under contrib/tools/server-everything.
Learn more

Agent Memory