How I Built a Health Data API With Zero Dependencies (And Why You Should Too)

Every health app I've seen follows the same pattern: user enters data → data goes to server → server queries database → response comes back. But what if your health tool didn't need a server at all? I built an herb-drug interaction checker that runs entirely in the browser. 592 interactions, autocomplete search, severity ratings — all client-side. Zero API calls. Zero backend. Zero privacy concerns. Here's what I learned building it, and why this architecture makes sense for health tools specifically. Why Client-Side for Health Data? Health data is sensitive. When someone searches "metformin + St. John's Wort," they're telling you they take metformin (diabetes) and are considering St. John's Wort (depression). That's two diagnoses revealed in one query. With a server-side API, you're collecting that data whether you want to or not. Server logs, analytics, database queries — all contain sensitive health information subject to regulations you probably don't want to deal with. Client-side