One thing I have always wanted to do is cancel an AI Agent executing remotely that I kicked off as it streamed its part by part response(part could words, list of urls or whatever you want the FE to display). A good example is web-researcher agent that searches and fetches web pages remotely and sends it back to the local sub-agent to summarize the results. This is something claude-code in the terminal does not quite provide. In Instant would this be trivial to build?

Here is how I built it in a WUI: I sent SSE events from Server -> Client streaming web-search progress, but then the client could update a `x` box on "parent" widget using the `id` from a SSE event using a simple REST call. The `id` could belong to parent web-search or to certain URLs which are being fetched. And then whatever is yielding your SSE lines would check the db would cancel the send(assuming it had not sent all the words already).