# Reactive runtime compatibility correction

The original Captcha component attempted to execute full native JavaScript inside WRNexusJS behavior blocks. WRNexusJS 0.3.6 behavior blocks use a deliberately limited eval-free interpreter and do not execute arbitrary JavaScript syntax.

The corrected design keeps the `.wrn` component declarative and delegates network, audio, timers, provider SDKs, DOM updates, and form guards to a packaged same-origin browser runtime.

This removes the `Unexpected token '?'` mount failure and prevents the later failures that would have occurred for `async`, `await`, `try`, callback functions, constructors, and member assignments.