Inspiration We walk past history every day without knowing it. A flooded street in Queens is often caused by a buried 19th century creek. A vacant lot was once a community hub. A neighborhood's name traces back to a group that was pushed out decades ago. We built Where You At to answer the question: "What actually happened here?" and layer it with what people are saying about it today, plus real safety data.
What it does Type any address, neighborhood, or city. Where You At gives you three layers instantly:
History - AI-generated archival deep dive: urban development, key eras, cultural shifts, and forgotten stories Reddit Pulse - Gemini AI summarizes what the community is actually saying about the area: sentiment, recurring themes, and hot takes Safety - Live registered offender data within a 1-mile radius, broken down by risk level How we built it React 19 + TypeScript + Vite for the frontend Google Gemini 2.5 Flash for both the history narrative and Reddit community summary - both fire in parallel using Promise.allSettled so neither blocks the other Supabase (Postgres) as a cache layer with 24hr TTL - repeat searches are instant, no redundant API calls Offenders.io API for real registered offender data OpenStreetMap Nominatim for geocoding - every search is validated against real geographic data before anything else runs, so gibberish gets rejected immediately Vite dev proxies to handle CORS for external APIs Challenges we ran into The biggest one was the Gemini API - the model names kept changing and some weren't available for new accounts. We also had to architect the caching carefully so stale data doesn't serve after a schema change. Getting the location validation to run before the cache check (not after) was a subtle but important fix. CORS was a constant battle across three different external APIs.
What we learned Parallel async architecture matters more than you'd think - running both Gemini calls simultaneously cut perceived load time nearly in half. We also learned that geocoding-based validation is the right gate: if Nominatim can't find it, nothing else should even try.
What's next Adding walkability scores, transit access, and gentrification index overlays. We want this to become the layer underneath every neighborhood conversation.
Built With
- next.js
- postgressql
- sql
- supabase
- tailwindcss
- typescript
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