Fanout — watch AI agents research

What it is

Type a question and watch a team of AI agents research it in real time: a planner breaks it into sub-questions, searchers work the web in parallel, a skeptic tries to tear their findings down, and a writer streams a report with sources. Anyone can watch recorded runs instantly for free — or paste their own API key and run it live.

The trust problem

Asking strangers to paste an API key into a website is a big ask. So Fanout has no backend at all — the page is static files, and the browser's own security policy physically blocks the key from going anywhere except the AI provider. It's not a promise; anyone can verify it in DevTools or the source.

How I built it

The same way I built this site, scaled up: I wrote the spec, then directed a pipeline of AI agents — a fresh one implemented each task, another reviewed it adversarially, and I ruled on what mattered. The reviews caught six real bugs that were baked into my own plan, including one where cancelling a run would quietly corrupt the recording, and one where a double-click could spend a visitor's money on two runs at once.

The takeaway

An app about AI agents checking each other's work — built by AI agents checking each other's work.