WhatsApp MCP Server

Instructions

Implementation Reference

• src/whatsapp_mcp/whatsapp_client.py:144-163 (handler)

  The actual implementation of the send_message tool logic.

  async def send_message(
      self,
      text: str,
      phone_number: str | None = None,
      chat_name: str | None = None,
  ) -> dict[str, Any]:
      await self._require_ready()
      assert self._page is not None
  
      target = await self._open_target_chat(phone_number=phone_number, chat_name=chat_name, prefill_text=text)
      await self._wait_for_message_box()
      if target["type"] == "chat_name":
          await self._fill_message_box(text)
      await self._click_first_visible(SEND_BUTTON_SELECTORS)
  
      return {
          "status": "sent",
          "target": target,
          "message": text,
      }

• src/whatsapp_mcp/mcp_server.py:180-198 (registration)

  Registration and definition of the send_message tool in the MCP server.

  "send_message": ToolDefinition(
      name="send_message",
      description="Send a WhatsApp message using either a phone number or an existing chat name.",
      input_schema={
          "type": "object",
          "properties": {
              "phone_number": {"type": "string", "description": "Recipient phone number in international or local format."},
              "chat_name": {"type": "string", "description": "Visible WhatsApp chat name to open from the sidebar search."},
              "text": {"type": "string", "description": "Message body to send."},
          },
          "required": ["text"],
          "additionalProperties": False,
      },
      handler=lambda args: self.client.send_message(
          text=args["text"],
          phone_number=args.get("phone_number"),
          chat_name=args.get("chat_name"),
      ),
  ),