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).

If I understood you correctly:

You kick off an agent. It reports work back to the user. The user can click cancel, and the agent gets terminated.

You are right, this kind of UX comes very naturally with Instant. If an agent writes data to Instant, it will show up right away to the user. If the user clicks an `X` button, it will propagate to the agent.

The basic sync engine would handle a lot of the complexity here. If the data streaming gets more complicated, you may want to use Instant streams. For example, if you want to convey updates character by character, you can use Instant streams as an included service, which does this extremely efficiently.

More about the sync engine: https://www.instantdb.com/product/sync More about streams: https://www.instantdb.com/docs/streams