Resource Subscriptions

import { MCPServer } from "mcp-use";
import { z } from "zod";

const server = new MCPServer({
  name: "settings-server",
  version: "1.0.0",
});

const settingsUri = "settings://app";
let theme = "light";

server.resource({ name: "app-settings", uri: settingsUri }, async (uri) => ({
  contents: [
    {
      uri: uri.href,
      mimeType: "application/json",
      text: JSON.stringify({ theme }),
    },
  ],
}));

server.tool(
  {
    name: "set-theme",
    inputSchema: z.object({ theme: z.enum(["light", "dark"]) }),
  },
  async ({ theme: nextTheme }) => {
    theme = nextTheme;
    await server.notifyResourceUpdated(settingsUri);

    return {
      content: [{ type: "text", text: `Theme changed to ${theme}.` }],
    };
  },
);

export default server;

await server.notifyResourcesChanged();

cd libraries/typescript/packages/server/examples/notifications
pnpm dev