Add character limit to RASA button

My button is not realy a button. It’s more like a free text field where the user (customer) can specify it’s concern. Before the user starts to type anything, the text field in the browser is higlighted with a grey title.

  utter_ask_customer_problem:
  - text: Please tell me your concern in just a few words!.
    buttons:
      - title: What can we improve?
        payload: "user_concern"

The button works great. But there is a problem: The user writes to many words.

I want to limit the number of characters to 50. Can I add some kind of metadata (e.g. max_length=50) to the button? I want the user to be able to see the number of left charaters in the messenger.

I know I can limit the number of characters in the backend of Rasa. But I want the user to clearly see, how many characters he has left.

Do you have a custom chat interface? You can create a UI component beside your text input field that indicates the number of characters left by capturing the typing event in JS

From backend, simply pass metadata to the channel that indicates the character limit for that question.