Hyperlocal Spatial Intelligence & 10-Year US Census Shift Tracker for Any American Neighborhood.
- Instant ZIP Code Intelligence: Resolve any 5-digit US ZIP code to extract live commercial changes, physical renovations, and unlisted places.
- Official US Census Bureau Demographics: Real-time ZCTA metrics covering Median Household Income, Population Growth, Housing Occupancy, Median Home Values, and 10-Year historical baselines.
- Neighborhood Vitality Index (0–100): Multi-factor vitality algorithm scoring income trajectories (35%), commercial opening velocity (30%), housing occupancy (20%), and civic density (15%).
- Side-by-Side Area Comparison (
/compare): Direct head-to-head benchmarking between any two US neighborhoods with metric scorecards and dynamic SEO cards. - Map Time Machine: Scrub historical eras (
2024–Present,2021–2023,2018–2020,All History) with animated vector map pins. - Crime & Safety Context: FBI Crime Data Explorer state trends plus real incident heatmaps from supported official municipal Socrata portals. Unsupported cities show trend-only coverage instead of generated incidents.
- School Access & Education Resources: Nearby public schools from the official NCES EDGE Common Core of Data, including enrollment, grade span, student/teacher ratios, distance, and a transparent access/resources index.
- Dated Street Imagery: Before/after comparison of compatible crowdsourced KartaView captures, with capture dates, source links, and explicit no-coverage states.
- AI Neighborhood Assistant (
/ai): Ask ZIP-specific questions and receive structured answers with a conclusion, evidence sections, demographic context, and recent map-record signals. - 1-Click Shareable Infographics: Generate high-resolution 1200x630 dark-theme social PNGs or post directly to X with pre-formatted stats.
| Layer | Technology |
|---|---|
| Framework | Next.js 15 (App Router with Server Components & Dynamic SEO) |
| Frontend | React 19, TypeScript, Tailwind CSS v4, Lucide Icons |
| Map Visualization | MapLibre GL + Carto Dark Vector Tiles |
| Data Sources | US Census ACS, FBI Crime Data Explorer, municipal Socrata portals, NCES EDGE, KartaView, Overpass, Wikipedia |
| AI Analysis | Groq API (GPT OSS 120B / 20B with multi-model failover), server-side structured responses |
| Database & Auth | Supabase (PostgreSQL with RLS) + Local Offline Fallbacks |
git clone https://github.com/nilaymallikk/what-changed.git
cd what-changed
npm installCreate a .env file in the root directory:
CENSUS_API_KEY=your_census_api_key_here
NEXT_PUBLIC_SUPABASE_URL=https://your-project.supabase.co
NEXT_PUBLIC_SUPABASE_ANON_KEY=your_supabase_anon_key
GROQ_API_KEY=your_server_side_groq_keyKeep GROQ_API_KEY server-side. Never expose it through a NEXT_PUBLIC_ variable.
npm run devOpen http://localhost:3000 in your browser.
# Lint codebase
npm run lint
# Build production bundle
npm run build
# Start production server
npm run startBuilt with precision by Nilay Mallik.
Open-source under the MIT License.