Tinderbox automatically communicates with the streaming preview of the application Marked2. When you select or edit a note using the Markdown prototype in Tinderbox, it will automatically be sent to the Marked2 streaming preview window.
Note it is a $Prototype value of 'Markdown', not the prototype's attribute customisations that trigger preview streaming.
Export code operators in the note $Text, e.g. ^value()^, are evaluated in the data passed to Marked 2.
More on Markdown use in Tinderbox.