zipcheck

Available home-safety evidence for a US ZIP code, right in your terminal. Unknown and insufficient-coverage values remain explicit.

Setup

Since 2026-08-19 the API requires a key. Free, no card:

1. Get one at zipcheckup.com/api/pricing/
2. export ZIPCHECKUP_API_KEY=zc_live_...

The key is read from the environment rather than a flag or a config file: a flag ends up in shell history, a config file ends up committed.

npx zipcheck 10001

  ┌─────────────────────────────────────────┐
  │  Home Safety Report: ZIP 10001          │
  └─────────────────────────────────────────┘

  Grade:  B (72/100)
  Location:  New York, NY (New York County)
  Population:  21,102
  Water System:  NEW YORK CITY (Surface water)

  Health Violations (5yr):  0
  Lead Level:  0.004 mg/L
  Radon Risk:  Zone 3 (Low)

  National Rank:  Better than 68% of US ZIPs

  Full report: https://zipcheckup.com/report/10001/
  Data: EPA SDWIS, FEMA, Census, CDC | CC BY 4.0

Features

• Versioned safety grade when all required model domains have sufficient evidence
• Water evidence with unknown values kept distinct from measured zero
• Environmental risks — radon zones, flood claims, air quality
• Compare two ZIPs side by side
• JSON output for scripting and automation
• Zero dependencies — just Node.js 14+

Usage

# Check a ZIP code
npx zipcheck 90210

# JSON output (for piping/scripting)
npx zipcheck 10001 --json

# Compare two ZIP codes
npx zipcheck --compare 10001 90210

Data Sources

All data from official US government sources:

• EPA SDWIS (water quality, violations)
• FEMA NFIP (flood claims)
• U.S. Census (demographics, housing)
• CDC (health risk factors)
• EIA (energy costs)
• USGS (radon zones)
• And 9 more federal databases

Full methodology at zipcheckup.com/press/

API

The CLI calls the public ZipCheckup API:

GET https://api.zipcheckup.com/v1/zip/{zip}
GET https://api.zipcheckup.com/v1/zip/{zip}/score

Both take X-API-Key. Rate limit is 100 requests per day on the free tier, counted per key, resetting at midnight UTC — one ZIP lookup uses two requests. Higher limits, bulk lookup and CSV export are on the paid tier: zipcheckup.com/api/pricing/. Full reference: zipcheckup.com/api/docs/.

Upgrading from 1.x

1.x sent no key and stopped working when the API began requiring one. Set ZIPCHECKUP_API_KEY and it works again. Nothing else changed: same commands, same output.

The old README said the limit was 100 requests per minute. It was never that — the worker has counted 100 per day since it was written.

License

MIT — Data is CC BY 4.0 (attribution required).

Built by ZipCheckup. Check the full report for source, vintage, and geographic-coverage limitations.