Code boxes in Tinderbox will autocomplete action and query code. This occurs in relevant Inspector and Get Info tabs. From v6.6.0, dot-operators are offered after a period is typed after an operator or attribute name.
If '=' is typed after $Prototype, auto-completions are offered for existing defined prototypes. As the process covers bother query and action use, care should be taken to use '==' in a query context, or in a find(), and '=' elsewhere.