Variable RESOURCE_URI_META_KEY`Const`

RESOURCE_URI_META_KEY: "ui/resourceUri"

Metadata key for associating a resource URI with a tool call.

MCP servers include this key in tool call result metadata to indicate which UI resource should be displayed for the tool. When hosts receive a tool result containing this metadata, they resolve and render the corresponding App.

Note: This constant is provided for reference. MCP servers set this metadata in their tool handlers; App developers typically don't need to use it directly.

Example: How MCP servers use this key (server-side, not in Apps)

// In an MCP server's tool handler:
return {
  content: [{ type: "text", text: "Result" }],
  _meta: {
    [RESOURCE_URI_META_KEY]: "ui://weather/forecast"
  }
};

Example: How hosts check for this metadata (host-side)

const result = await mcpClient.callTool({ name: "weather", arguments: {} });
const uiUri = result._meta?.[RESOURCE_URI_META_KEY];
if (uiUri) {
  // Load and display the UI resource
}

Variable RESOURCE_URI_META_KEYConst

Example: How MCP servers use this key (server-side, not in Apps)

Example: How hosts check for this metadata (host-side)

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Variable RESOURCE_URI_META_KEY`Const`