UI resources

Some Kontext tools don’t just return JSON — they return a UI resource the client can render inline. This uses the MCP Apps extension: the tool response carries a _meta.ui.resourceUri pointing at an HTML resource the server also serves. An MCP-Apps-aware client (Claude, for instance) fetches that resource and renders it as an inline widget that reads the tool’s result. Clients that don’t support UI resources still get the underlying JSON payload — the tool call remains fully usable for headless agents, and only loses the visual layer.

Example — `get_insights_chart`

get_insights_chart takes a product, a chart type, and an optional date range:

{
  "tool": "get_insights_chart",
  "arguments": {
    "productId": "prod_abc123",
    "chartType": "detected-problems-trend",
    "granularity": "weekly",
    "dateFrom": "2026-01-01",
    "dateTo": "2026-04-01"
  }
}

The response includes the raw series data and a _meta block pointing at the UI resource:

{
  "content": [{ "type": "text", "text": "{ \"series\": [ ... ] }" }],
  "_meta": {
    "ui": { "resourceUri": "ui://insights/chart.html" }
  }
}

UI-aware clients then fetch ui://insights/chart.html via the MCP resources/read method, and render it as an interactive chart inline in the conversation. The rendered view reads the same series data shown above and draws it — so the agent can still reason about the numbers in text, while the user sees the chart.

Future UI resources

This is the first Kontext tool to return a UI resource. More are on the roadmap — the pattern is the same: the tool’s _meta.ui.resourceUri names the rendered view, and the server exposes that URI as a resource.

Getting Started

Reference

Example — `get_insights_chart`

Future UI resources

​Example — get_insights_chart

​Future UI resources

Example — `get_insights_chart`

Future UI resources