HN Community. Need your help in finding the right chat solution

Hi HN community We are building an AI powered chatbot assistant for daily needs like booking a cab, paying a phone /electricity bill, finding a good place to eat etc. Since the NLP is not that evolved, we have a functionality where if the bot is confused or does not get the context, we plan to transfer it to a human agent so that the customer does not have a bad experience.

Here is where we are facing trouble: We want to keep the switch between the human and bot on the server side. However, we are not able to find a solution where we can use an API or a code to send messages as a visitor. When a human agent sees this, he replies to the message, we take the message from the server side and show it to the user. (the user will be informed that he is talking to a human instead of a bot, but we want to keep the Ui interface the same). Can you guys please suggest us some API for the same? We have tried zendesk but it needs a UI somewhere and did not work in android. We have tried Live chat inc but it does not have the websocket so it wont be a live connection. Anything else that we can use? Our primary requirement is to make a seamless switch on the server side and connect a user with a human agent in case the Bot is unable to understand context.

Thanks a lot for your help.