I read slowly. Not because I'm patient, but because half the concepts in any given article have load-bearing context I'm missing — and I've spent years either tab-switching into distraction or skipping past terms and pretending I got the gist.
So I built rabbitholes, a Chrome extension that renders an explanation next to your cursor the moment you highlight text. No new tab. No context switch. The tooltip lives in a shadow DOM, so it doesn't touch the host page's styles or layout.
The part I use most: every explanation ends with two suggested rabbit-hole topics — the threads that actually matter from where you currently are. One click takes you there. The extension tracks how many hops deep you've gone, which sounds like a gimmick until you've landed on philosophy from a Wikipedia article about bread and want to retrace how you got there.
If you want to go further, there's a pencil icon for follow-up questions that inherit the current context as background, and a globe icon that re-runs the query enriched with Brave Search results and attaches clickable source chips to the response.
Requests go directly from your browser to api.anthropic.com and api.search.brave.com — no intermediary server, zero telemetry, no analytics. Your Anthropic API key sits in chrome.storage.sync and never leaves the browser. Manifest V3 throughout.
The model is Claude Haiku 4.5, which is fast enough that the tooltip feels instant rather than like a loading state.