Markup Agent

Paste in the address of any website and Markup Agent loads it through a server-side proxy, then lets you click on individual elements to drop a pin and write a comment against them. When you are done you copy the link. Whoever opens it sees the same page with your pins sitting on the same elements. There is no account to create and nothing is stored anywhere — the target address and every annotation are base64-encoded into the querystring, so the link is the document.

I built it because giving feedback on a web page usually degrades into screenshots pasted into a chat window, where the picture is separated from the thing it is about. A link that reopens the live page with the notes still attached felt like the smallest version of that idea worth trying.

The statelessness is a genuine constraint rather than a flourish. Pins are anchored by XPath so they survive small layout changes, but they still drift between very different viewport sizes, and freehand drawing remains unbuilt because strokes are far more data to carry in a URL than a pin. The idea of turning markup into structured prompts for a coding agent is still just an idea.