How it works
Six sources. One brief. 90 seconds.
Every appeal Houseproof writes is fed by six independent data pulls, all firing in parallel the moment you drop your address. Here's every source, what's live vs. mocked, and which AI does the actual reasoning.
01 · Parcel + ownership
● MOCKAPN, legal description, lot size, year built, building square footage, beds/baths. Required for every appeal — establishes the property identity in the county system.
Provider chain
County GIS · Texas A&M Real Estate Center
Status
Mocked deterministically per address (real provider chain: LandGlide / ATTOM / Regrid / county GIS — keys pending).
02 · Assessed value (DCAD live)
● MOCKCurrent-year assessed value, market value, exemptions on file (homestead / over-65 / disabled / etc.), tax rate. The number we're actually trying to lower.
Provider chain
dallascad.org HTML scrape · Collin + Tarrant scrapers next
Status
Best-effort live scrape on Dallas. DCAD uses ASP.NET WebForms with VIEWSTATE — production scrape needs Playwright headless. Mock fallback today.
03 · Three nearest comps
● MOCKThree most-comparable sales from the last 12 months within ~1 mile. Sold price, date, sqft, distance. Cited verbatim in the brief's comp-based argument.
Provider chain
MLS partners (Repliers, RentSpree) · Zillow public · Realtor.com
Status
Mocked. MLS keys are ~$300/mo + qualification; we wire as paying customers cross $50k MRR.
04 · Aerial photo + AI condition scoring
● LIVETop-down satellite image at 19-zoom, then Gemini scores roof (0-100), lot maintenance (0-100), structural-from-above (0-100), and writes appeal-worthy notes. Real evidence the appraiser can see for themselves.
Provider chain
ESRI World Imagery (free, NAIP-quality) → Gemini 2.5 Flash vision
Status
LIVE. Try any address on /check-property.
05 · Permit history
● LIVEEvery permit filed against the address in the last 10 years: type, description, declared value, status. Zero permits = no improvements = arguments for lower valuation. Lots of permits = the assessor has already over-baked them.
Provider chain
Dallas City Open Data (Socrata) · BuildZoom (paid) · city-by-city
Status
LIVE for Dallas via dallasopendata.com/resource/e7gq-4sah. Plano + Allen scrape next.
06 · 5-year tax history
● MOCKYear-over-year assessed value trajectory, taxes paid, delinquency flags. Establishes pattern of over-assessment over time.
Provider chain
County tax assessor sites (DCAD ACT, Collin CAD, Tarrant ACT)
Status
Mocked from deterministic generator. Real scrapers slot in alongside assessor scrapers.
AI providers
We pick the model that's fast, accurate, and in budget today.
| Model | Use | Cost | Latency |
|---|---|---|---|
| Gemini 2.5 Flash | Vision condition scoring + appeal brief generation | ~$0.0005 / brief | 4-8s |
| GPT-4o-mini | Backup for Gemini (currently quota-limited) | ~$0.001 / brief | 3-6s |
| Claude Sonnet 4.6 | Backup for Gemini (currently rate-limited) | ~$0.003 / brief | 5-10s |
Pieter Mode: we route to whichever model has budget. Failover chain so the demo never breaks.