Copilot iFrame Messaging POC

I need to prove—quickly and conclusively—that a Copilot Studio agent embedded in an iFrame can execute JavaScript that posts a plain-text message back to its parent HTML page. A small, clean proof of concept is all that’s required; no error handling needs to surface in the host page.

Here’s the flow I want to see:
1. Parent page loads and hosts an iFrame that points to the Copilot Studio web chat experience.
2. The agent runs, triggers a JavaScript snippet, and sends a plain-text string (any short confirmation text is fine) to the parent.
3. The parent page captures that message—`window.postMessage` or a comparable approach is acceptable—and writes it visibly in the DOM so anyone can see the round-trip was successful.

Keep frameworks out of scope; a simple vanilla HTML/JS page is sufficient, but if you prefer React, Angular, or Vue, that’s fine so long as setup remains minimal.

Deliverables:
• Copilot Studio configuration file(s) or export showing the custom action that emits the message
• Parent HTML page with the embedded iFrame and the JavaScript listener that outputs the received text
• Short README explaining local setup and any Copilot Studio settings I must replicate on my tenant

If you’ve done similar integrations before and can spin up this demo swiftly, let’s get started—confidence in feasibility is essential.