GPT Autoresponder features auto-reply functionality for your instant messengers , currently supporting Whatsapp, Whatsapp Business, Telegram and Signal, by integrating OpenAI Platform APIs.
You should have your API key from OpenAI Platform before activating the auto-reply service.
The technology 100% relies on the "android.permission.BIND_NOTIFICATION_LISTENER_SERVICE" permission in Android device. It grants the right to listen to the incoming push notifications and reply to the messages directly through the notification widgets.
For Signal users, due to the restriction by itself, an incoming new chat request must be accepted before the conversation starts. Therefore it will only reply to all users on the contact list (upon message request accepted by you).