Open MCP Server

Implementation Reference

• src/tools/web-tools.ts:30-56 (handler)

  The core handler function for the 'fetch_url' tool that executes the HTTP request using fetchWithTimeout, processes the response text and headers, and returns formatted content and metadata.
  async ({ url, method, headers, body, timeout, followRedirects }) => { return wrapToolExecution(async () => { const response = await fetchWithTimeout(url, { method, headers, body, timeout, followRedirects }); const responseText = await response.text(); const responseHeaders = extractHeaders(response); return { content: [{ type: "text" as const, text: responseText }], metadata: { status: response.status, statusText: response.statusText, headers: responseHeaders, url: response.url } }; }, { errorCode: ERROR_CODES.HTTP_REQUEST, context: "Failed to fetch URL" }); }
• src/tools/web-tools.ts:22-28 (schema)

  Zod schema for input validation of the 'fetch_url' tool parameters: url (required), method, headers, body, timeout, followRedirects.
  { url: z.string().url("Valid URL is required"), method: z.enum(["GET", "POST", "PUT", "DELETE", "PATCH"]).optional().default(DEFAULTS.HTTP_METHOD), headers: z.record(z.string()).optional().default({}), body: z.string().optional(), timeout: z.number().optional().default(DEFAULT_TIMEOUTS.HTTP_REQUEST), followRedirects: z.boolean().optional().default(DEFAULTS.HTTP_FOLLOW_REDIRECTS)
• src/tools/web-tools.ts:20-58 (registration)

  The registerFetchUrl function that directly registers the 'fetch_url' tool on the MCP server using server.tool(), including schema and handler.
  function registerFetchUrl(server: McpServer): void { server.tool("fetch_url", { url: z.string().url("Valid URL is required"), method: z.enum(["GET", "POST", "PUT", "DELETE", "PATCH"]).optional().default(DEFAULTS.HTTP_METHOD), headers: z.record(z.string()).optional().default({}), body: z.string().optional(), timeout: z.number().optional().default(DEFAULT_TIMEOUTS.HTTP_REQUEST), followRedirects: z.boolean().optional().default(DEFAULTS.HTTP_FOLLOW_REDIRECTS) }, async ({ url, method, headers, body, timeout, followRedirects }) => { return wrapToolExecution(async () => { const response = await fetchWithTimeout(url, { method, headers, body, timeout, followRedirects }); const responseText = await response.text(); const responseHeaders = extractHeaders(response); return { content: [{ type: "text" as const, text: responseText }], metadata: { status: response.status, statusText: response.statusText, headers: responseHeaders, url: response.url } }; }, { errorCode: ERROR_CODES.HTTP_REQUEST, context: "Failed to fetch URL" }); } ); }
• src/index.ts:66-66 (registration)

  Invocation of registerWebTools(server) in the main server initialization, which calls registerFetchUrl to register the tool.
  registerWebTools(server);
• src/tools/web-tools.ts:63-98 (helper)

  Key helper function fetchWithTimeout used by the handler to perform HTTP fetches with configurable timeout, method, headers, body, and redirect handling using AbortController.
  async function fetchWithTimeout( url: string, options: { method: HttpMethod; headers?: Record<string, string>; body?: string; timeout: number; followRedirects: boolean; } ): Promise<Response> { const { method, headers, body, timeout, followRedirects } = options; const controller = new AbortController(); const timeoutId = setTimeout(() => controller.abort(), timeout); const requestInit: RequestInit = { method, headers, signal: controller.signal, redirect: followRedirects ? "follow" : "manual" }; if (body && ["POST", "PUT", "PATCH"].includes(method)) { requestInit.body = body; } try { const response = await fetch(url, requestInit); return response; } catch (error) { if (error instanceof Error && error.name === 'AbortError') { throw new Error(`Request timeout after ${timeout}ms`); } throw error; } finally { clearTimeout(timeoutId); }