RealtorZip combines official government APIs, publisher-authorized research downloads, and human-reviewed professional records. Each metric keeps its source, attribution, geography, period, freshness, and interpretation boundary.
Approved sources
42
Nationwide public-data and authority sources
Connected now
6
No-key or configured official services
Free credentials
8
Sources ready after adding a free token
Official downloads
23
Bulk datasets ready for attributed import
Access policy
RealtorZip uses official APIs, official downloads, and human-reviewed public records. It does not scrape consumer listing pages, agent pages, or sources whose terms prohibit automated reuse. Every public metric carries source, period, geography, attribution, and freshness metadata.
Source class
2 approved sources
U.S. Department of Housing and Urban Development
A free HUD User token is required.
Attribution: U.S. Department of Housing and Urban Development, HUD User
Open official documentation →U.S. Department of Housing and Urban Development
Aggregate affordability context; never use it for steering or protected-class targeting.
Attribution: HUD Comprehensive Housing Affordability Strategy data
Open official documentation →Source class
3 approved sources
U.S. Census Bureau
A free Census Data API key is required for all data queries as of July 2026.
Attribution: U.S. Census Bureau, American Community Survey 5-year estimates
Open official documentation →Centers for Disease Control and Prevention
Use for public-interest context, never to rank or exclude protected communities.
Attribution: CDC/ATSDR Social Vulnerability Index
Open official documentation →U.S. Census Bureau
Public-interest context only. Never use resilience estimates to rank agents, exclude communities, target protected classes, or make suitability decisions.
Attribution: U.S. Census Bureau Community Resilience Estimates
Open official documentation →Source class
3 approved sources
U.S. Bureau of Labor Statistics
The no-key API is used for national context; a free key increases quotas.
Attribution: U.S. Bureau of Labor Statistics
Open official documentation →U.S. Bureau of Economic Analysis
A free BEA API key is required.
Attribution: U.S. Bureau of Economic Analysis
Open official documentation →U.S. Census Bureau
The Census Bureau currently requires a free API key for CBP/ZBP queries. Published suppression flags and disclosure protections remain authoritative.
Attribution: U.S. Census Bureau County and ZIP Code Business Patterns
Open official documentation →Source class
1 approved source
National Center for Education Statistics
RealtorZip must not create or imply unsupported school-quality rankings.
Attribution: National Center for Education Statistics
Open official documentation →Source class
4 approved sources
U.S. Environmental Protection Agency
Facility counts are screening context and are not environmental risk conclusions.
Attribution: U.S. EPA Facility Registry Service
Open official documentation →U.S. Environmental Protection Agency
Screening context only. Do not convert EJScreen or demographic indicators into neighborhood grades, agent rank, eligibility, steering, or property-value claims.
Attribution: U.S. Environmental Protection Agency EJScreen
Open official documentation →USDA Natural Resources Conservation Service
Property interpretation requires site-specific professional review.
Attribution: USDA Natural Resources Conservation Service SSURGO
Open official documentation →U.S. Environmental Protection Agency
Use validated AQS extracts for analysis; monitor coverage varies by pollutant and area.
Attribution: U.S. EPA Air Quality System AirData
Open official documentation →Source class
8 approved sources
Federal Emergency Management Agency
Historical declarations are context, not a property-specific risk determination.
Attribution: FEMA OpenFEMA Disaster Declarations Summaries
Open official documentation →U.S. Geological Survey
Integrated under the publisher's official access and attribution requirements.
Attribution: U.S. Geological Survey Earthquake Hazards Program
Open official documentation →NOAA National Centers for Environmental Information
A free CDO token is required; observations depend on local station coverage.
Attribution: NOAA National Centers for Environmental Information
Open official documentation →Federal Emergency Management Agency
Integrated under the publisher's official access and attribution requirements.
Attribution: FEMA National Risk Index
Open official documentation →Federal Emergency Management Agency
Flood-zone determinations must be coordinate/property-specific, not inferred from ZIP averages.
Attribution: FEMA National Flood Hazard Layer
Open official documentation →NOAA National Weather Service
Alerts are current public-safety notices, not historical climate data or a property-specific hazard determination. Requests are cached and rate-limited.
Attribution: NOAA National Weather Service
Open official documentation →NOAA National Centers for Environmental Information
Event records are historical context and may be revised by NOAA.
Attribution: NOAA National Centers for Environmental Information Storm Events Database
Open official documentation →Federal Emergency Management Agency
Publish only properly aggregated statistics. Redaction and suppression must be preserved; claims do not establish the risk or insurance status of a property.
Attribution: FEMA OpenFEMA NFIP Redacted Claims
Open official documentation →Source class
2 approved sources
Federal Reserve Bank of St. Louis
A free FRED API key is required.
Attribution: Federal Reserve Bank of St. Louis, FRED
Open official documentation →Freddie Mac
Integrated under the publisher's official access and attribution requirements.
Attribution: Freddie Mac Primary Mortgage Market Survey
Open official documentation →Source class
6 approved sources
Zillow Group
Use only Zillow Research's authorized downloads with required attribution. Never scrape Zillow listing or professional-profile pages.
Attribution: Zillow Research
Open official documentation →Realtor.com
Use official downloads and preserve Realtor.com attribution and source links.
Attribution: Realtor.com Economic Research
Open official documentation →Redfin
Use Redfin Data Center downloads; do not scrape listings or MLS-restricted exports.
Attribution: Redfin Data Center
Open official documentation →Federal Housing Finance Agency
Integrated under the publisher's official access and attribution requirements.
Attribution: Federal Housing Finance Agency House Price Index
Open official documentation →U.S. Census Bureau
Integrated under the publisher's official access and attribution requirements.
Attribution: U.S. Census Bureau Building Permits Survey
Open official documentation →U.S. Department of Housing and Urban Development
Use the official aggregated release; never infer vacancy for a specific address.
Attribution: HUD User aggregated USPS vacancy data
Open official documentation →Source class
7 approved sources
U.S. Census Bureau
Integrated under the publisher's official access and attribution requirements.
Attribution: U.S. Census Bureau Geocoder and TIGER/Line geography
Open official documentation →Federal Communications Commission
Integrated under the publisher's official access and attribution requirements.
Attribution: Federal Communications Commission National Broadband Map
Open official documentation →U.S. Energy Information Administration
Integrated under the publisher's official access and attribution requirements.
Attribution: U.S. Energy Information Administration
Open official documentation →National Park Service
Integrated under the publisher's official access and attribution requirements.
Attribution: National Park Service National Register of Historic Places
Open official documentation →OpenStreetMap contributors
Production use must follow tile/API/Overpass policies or use an approved provider/self-hosted endpoint. The public community endpoints are not a bulk backend.
Attribution: © OpenStreetMap contributors
Open official documentation →U.S. Department of Transportation, Bureau of Transportation Statistics
Integrated under the publisher's official access and attribution requirements.
Attribution: U.S. DOT Bureau of Transportation Statistics
Open official documentation →Federal Highway Administration
Bridge records are infrastructure context, not engineering advice.
Attribution: Federal Highway Administration National Bridge Inventory
Open official documentation →Source class
1 approved source
Consumer Financial Protection Bureau and FFIEC
Integrated under the publisher's official access and attribution requirements.
Attribution: Consumer Financial Protection Bureau and FFIEC HMDA data
Open official documentation →Source class
3 approved sources
U.S. Census Bureau
Integrated under the publisher's official access and attribution requirements.
Attribution: U.S. Census Bureau LEHD Origin-Destination Employment Statistics
Open official documentation →Internal Revenue Service
Integrated under the publisher's official access and attribution requirements.
Attribution: Internal Revenue Service Statistics of Income
Open official documentation →USDA Economic Research Service
ZIP values are approximations derived by USDA from tract classifications.
Attribution: USDA Economic Research Service
Open official documentation →Source class
1 approved source
Individual state and territorial regulators
There is no single unrestricted national public API. Connect jurisdiction by jurisdiction using approved APIs/downloads or human-reviewed public records.
Attribution: Applicable state real-estate licensing authority
Open official documentation →Source class
1 approved source
Federal Bureau of Investigation
Crime data requires careful denominator, coverage, and reporting-completeness disclosures and must not be converted into discriminatory neighborhood labels.
Attribution: Federal Bureau of Investigation Crime Data Explorer
Open official documentation →Non-negotiable boundary
RealtorZip uses the official API, download, attribution, retention, and rate-limit path for each source. It does not scrape Zillow, Realtor.com, Redfin, MLS, agent-profile, or consumer listing pages. State license records enter through approved jurisdiction-specific access or documented human review.
