WhatsApp Business MCP Server

Instructions

Implementation Reference

• src/whatsapp-client.ts:121-127 (handler)

  The core handler function in WhatsAppClient that executes the API request to send a text message.

  async sendTextMessage(to: string, body: string, previewUrl = false) {
    return this.request(`/${this.config.phoneNumberId}/messages`, "POST", {
      messaging_product: "whatsapp",
      to,
      type: "text",
      text: { preview_url: previewUrl, body },
    });

• src/index.ts:126-138 (registration)

  Registration of the send_text_message tool, including schema validation and the hook wrapper around the handler.

  server.tool(
    "send_text_message",
    "Send a text message to a WhatsApp number. Works within the 24-hour conversation window. For messages outside this window, use send_template_message instead.",
    {
      to: z.string().describe("Recipient phone number in international format (e.g., 5541999999999)"),
      body: z.string().describe("Message text content"),
      preview_url: z.boolean().optional().default(false).describe("Whether to show URL previews"),
    },
    async ({ to, body, preview_url }) =>
      executeWithHooks("send_text_message", { to, body, preview_url }, config, () =>
        wa.sendTextMessage(to, body, preview_url)
      )
  );