PyWA MCP Server

Instructions

Implementation Reference

• tools/templates.py:14-54 (handler)

  The main handler function for send_template tool. This async function sends WhatsApp template messages with parameters for recipient phone number, template name, language code, optional template parameters, and reply-to message ID. It calls the underlying pywa library's send_template method and returns a success/failure response with message details.

  async def send_template(
      to: str,
      name: str,
      language: str = "en",
      params: Optional[List[Dict[str, Any]]] = None,
      *,
      reply_to_message_id: Optional[str] = None,
  ) -> dict:
      """
      Send a WhatsApp template message.
      
      Args:
          to: Phone number or WhatsApp ID
          name: Template name/ID
          language: Template language code (default: en)
          params: Optional template parameters (header, body, button components)
          reply_to_message_id: Message ID to reply to
      
      Returns:
          Dictionary with success status and message ID
      """
      try:
          result = wa_client.send_template(
              to=to,
              name=name,
              language=language,
              params=params or [],
              reply_to_message_id=reply_to_message_id,
          )
          
          logger.info(f"Template '{name}' sent to {to}")
          message_id = getattr(result, 'id', str(result)) if result else None
          return {
              "success": True,
              "message_id": message_id,
              "template": name,
              "to": to,
          }
      except Exception as e:
          logger.error(f"Failed to send template: {str(e)}")
          return {"success": False, "error": str(e)}

• tools/templates.py:10-54 (registration)

  The registration function that creates and registers the send_template tool with the MCP server. This function defines the tool's schema via function signature and decorators, making it available for use by the MCP client.

  def register_template_tools(mcp, wa_client: WhatsApp):
      """Register template-related tools."""
      
      @mcp.tool()
      async def send_template(
          to: str,
          name: str,
          language: str = "en",
          params: Optional[List[Dict[str, Any]]] = None,
          *,
          reply_to_message_id: Optional[str] = None,
      ) -> dict:
          """
          Send a WhatsApp template message.
          
          Args:
              to: Phone number or WhatsApp ID
              name: Template name/ID
              language: Template language code (default: en)
              params: Optional template parameters (header, body, button components)
              reply_to_message_id: Message ID to reply to
          
          Returns:
              Dictionary with success status and message ID
          """
          try:
              result = wa_client.send_template(
                  to=to,
                  name=name,
                  language=language,
                  params=params or [],
                  reply_to_message_id=reply_to_message_id,
              )
              
              logger.info(f"Template '{name}' sent to {to}")
              message_id = getattr(result, 'id', str(result)) if result else None
              return {
                  "success": True,
                  "message_id": message_id,
                  "template": name,
                  "to": to,
              }
          except Exception as e:
              logger.error(f"Failed to send template: {str(e)}")
              return {"success": False, "error": str(e)}

• tools/templates.py:15-21 (schema)

  The schema/type definition for the send_template tool. Defined through Python type hints in the function signature, specifying that it takes a required string 'to' and 'name', an optional string 'language' with default 'en', optional list of dicts for 'params', and optional 'reply_to_message_id'. Returns a dictionary.

      to: str,
      name: str,
      language: str = "en",
      params: Optional[List[Dict[str, Any]]] = None,
      *,
      reply_to_message_id: Optional[str] = None,
  ) -> dict: