cronalert-mcp

Instructions

Implementation Reference

• src/index.ts:98-104 (handler)

  The create_monitor handler function that executes when the tool is called. It constructs a request with name, url, checkInterval, method, and expectedStatusCode, then POSTs to /monitors endpoint via apiRequest.

  async ({ name, url, checkInterval, method, expectedStatusCode }) => {
    const data = await apiRequest("/monitors", {
      method: "POST",
      body: JSON.stringify({ name, url, checkInterval, method, expectedStatusCode }),
    });
    return { content: [{ type: "text" as const, text: JSON.stringify(data, null, 2) }] };
  }

• src/index.ts:85-91 (schema)

  Input schema validation for create_monitor using zod. Defines required fields: name (string), url (string with URL validation), and optional fields: checkInterval (number, default 180), method (enum, default GET), expectedStatusCode (number, default 200).

  {
    name: z.string().describe("Display name for the monitor"),
    url: z.string().url().describe("URL to monitor"),
    checkInterval: z.number().int().positive().optional().default(180).describe("Check interval in seconds (default 180)"),
    method: z.enum(["GET", "POST", "PUT", "PATCH", "DELETE", "HEAD"]).optional().default("GET").describe("HTTP method (default GET)"),
    expectedStatusCode: z.number().int().optional().default(200).describe("Expected HTTP status code (default 200)"),
  },

• src/index.ts:82-105 (registration)

  Full tool registration for create_monitor using server.tool(). Includes tool name, description, schema definition, execution hints (readOnlyHint: false, destructiveHint: true), and the async handler function.

  server.tool(
    "create_monitor",
    "Create a new uptime monitor that periodically checks a URL and alerts on failure.",
    {
      name: z.string().describe("Display name for the monitor"),
      url: z.string().url().describe("URL to monitor"),
      checkInterval: z.number().int().positive().optional().default(180).describe("Check interval in seconds (default 180)"),
      method: z.enum(["GET", "POST", "PUT", "PATCH", "DELETE", "HEAD"]).optional().default("GET").describe("HTTP method (default GET)"),
      expectedStatusCode: z.number().int().optional().default(200).describe("Expected HTTP status code (default 200)"),
    },
    {
  
        readOnlyHint: false,
        destructiveHint: true,
        openWorldHint: false,
    },
    async ({ name, url, checkInterval, method, expectedStatusCode }) => {
      const data = await apiRequest("/monitors", {
        method: "POST",
        body: JSON.stringify({ name, url, checkInterval, method, expectedStatusCode }),
      });
      return { content: [{ type: "text" as const, text: JSON.stringify(data, null, 2) }] };
    }
  );

• src/index.ts:20-42 (helper)

  The apiRequest helper function used by create_monitor handler. Handles API authentication via Bearer token, sets Content-Type headers, makes HTTP requests to the CronAlert API, and handles error responses.

  async function apiRequest(
    path: string,
    options: RequestInit = {}
  ): Promise<unknown> {
    const apiKey = getApiKey();
    const url = `${API_BASE}${path}`;
  
    const response = await fetch(url, {
      ...options,
      headers: {
        "Content-Type": "application/json",
        Authorization: `Bearer ${apiKey}`,
        ...options.headers,
      },
    });
  
    if (!response.ok) {
      const body = await response.text();
      throw new Error(`API error ${response.status}: ${body}`);
    }
  
    return response.json();
  }