index.ts

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

const server = new MCPServer({
  name: "resource-watcher",
  title: "Resource Watcher",
  version: "1.0.0",
  description:
    "Resource subscriptions and dynamic lists — showcasing live resource updates",
});

let config: Record<string, string> = {
  theme: "light",
  language: "en",
  notifications: "on",
};

let featureFlags: Record<string, boolean> = {
  darkMode: true,
  betaFeatures: false,
};

server.resource(
  {
    name: "settings",
    uri: "config://settings",
    title: "Application Settings",
    description: "Current application configuration",
    mimeType: "application/json",
  },
  async (uri) => ({
    contents: [{ uri: uri.href, mimeType: "application/json", text: JSON.stringify(config) }],
  }),
);

const configOutputSchema = z.object({
  config: z.record(z.string(), z.string()),
  featureFlags: z.record(z.string(), z.boolean()),
});

export const showConfig = server.tool(
  {
    name: "show-config",
    description:
      "Display the configuration panel showing current settings and feature flags",
    inputSchema: z.object({}),
    outputSchema: configOutputSchema,
    view: {
      name: "config-panel",
      description: "Configuration panel with live settings and feature flag toggles",
      prefersBorder: true,
    },
  },
  async () => {
    const data = { config, featureFlags };
    return { content: [{ type: "text", text: "Config loaded" }], structuredContent: data };
  }
);

export const updateConfig = server.tool(
  {
    name: "update-config",
    description: "Update a configuration setting by key and value",
    inputSchema: z.object({
      key: z.string().describe("Configuration key to update"),
      value: z.string().describe("New value for the key"),
    }),
    outputSchema: configOutputSchema,
  },
  async ({ key, value }, ctx) => {
    config[key] = value;

    await server.notifyResourceUpdated("config://settings");

    await ctx.sendNotification("custom/config-changed", { key, value });

    const data = { config, featureFlags };
    return { content: [{ type: "text", text: `Updated "${key}" to "${value}"` }], structuredContent: data };
  }
);

export const toggleFeature = server.tool(
  {
    name: "toggle-feature",
    description: "Toggle a feature flag on or off",
    inputSchema: z.object({
      feature: z.string().describe("Feature flag name"),
      enabled: z.boolean().describe("Whether to enable the feature"),
    }),
  },
  async ({ feature, enabled }) => {
    featureFlags[feature] = enabled;

    await server.notifyToolsChanged();

    return { content: [{ type: "text", text: `Feature "${feature}" ${enabled ? "enabled" : "disabled"}` }] };
  }
);

export default server;