Most browser extensions that call an AI API route traffic through the developer's server. That means every sentence you highlight, every concept you look up, every follow-up question you type passes through infrastructure you don't control, gets logged or not logged at someone else's discretion, and lives in a database somewhere until it doesn't.

rabbitholes doesn't work that way. When you highlight a word and the tooltip fires, the request goes from your browser directly to api.anthropic.com. No intermediary. No proxy. No analytics ping on the side. The extension is Manifest V3, your Anthropic API key lives in chrome.storage.sync — encrypted, scoped to your browser profile, never transmitted to a third-party endpoint.

I built it this way because the tool's whole premise is that you should be able to look things up without friction — and "friction" includes having to decide whether you trust the developer's server with your reading habits. Direct-to-API removes that decision.

The same model applies to the search enrichment path. Click the globe icon and rabbitholes re-answers your query using Brave Search results. That request goes to api.search.brave.com directly. Source chips in the tooltip link back to the original pages. Nothing routes through me.

What the extension actually does: highlight any text on any page, and a shadow-DOM tooltip renders an explanation from Claude Haiku 4.5 next to your cursor without touching the host page's DOM. Click any word in the explanation to go deeper. Drag across a phrase to explore that instead. Every answer surfaces two suggested rabbit-hole topics — the most interesting threads from where you are. A counter tracks how many hops deep you've gone; if you tunnel far enough, you get a shareable trail.

The pencil icon opens a free-form follow-up input that inherits whatever context you've already built up in the current session.

Zero telemetry means I have no idea how many people use it or what they look up. That's the tradeoff, and it's the right one for a tool that sits on every page you read.

github.com/robertnowell/rabbitholes