`docs/B2B-DATA-MAP.md`

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# CRCP data by B2B-legality — what you can resell today at $0 data cost (2026-07-31)

The line is SOURCE, not fact. A sale price is a public fact, but if we got it from Redfin it's tainted;
if we got it from the county it's clean. Verified provenance per dataset from each fetcher's header.

## ✅ CLEAN — government public record, B2B / resale OK
| Dataset | Source (verified) | B2B value |
|---|---|---|
| **Assessor roll** `assessor.sqlite` (449MB, ~2.4M parcels) | LA County eGIS public ArcGIS layer | ownership, address, beds/baths/sqft/units, **use type**, **assessed value**, last **deed recording date**. NO sale price. |
| **Deed/transfer history** | derived from the assessor roll | last transfer date per parcel (AIN) |
| **FHA/HUD loans** `fha-loans.json` | HUD public | property + original mortgage amount + **INTEREST RATE** + origination date — lender intel |
| **FHA-approved condos** `fha-approved-condos.json` | HUD public | warrantability signal |
| **DRE license directory** `license-directory.json` / `licensed-agents.json` | CA DRE public license roll | legit, resellable agent/broker rolodex |
| **Demographics** `demographics.json` | US Census ACS | market context (rent, income, tenure) |
| **Geocoding** | US Census batch geocoder | lat/lng for mapping |
| **Assumable-loan heuristic** `assumable_estimate` | DERIVED (our IP) from FHA-public + property | "likely carries a sub-4% assumable FHA/VA loan" — a lead signal, our algorithm |

## ❌ TAINTED — aggregator-sourced, NOT clean for a B2B/resale product
| Dataset | Source | Doctrine status |
|---|---|---|
| `listings.json` / `ranked.json` (active listings) | **CREXi** | discovery-only; deal fields not resellable |
| `sfr-redfin.json` / `condos-redfin.json` | **Redfin** | aggregator |
| `closed-sales.json` (sale price+date) | **Redfin gis-csv** | tainted — re-source from the Recorder to clean |
| `redfin-agents` / `sfr-agents` | **Redfin** | aggregator |
| `broker-blocks` / `brokers-snapshot` | **CREXi** | broker IDENTITY is discovery-OK + cross-refs to DRE-public; CREXi contact fields are tainted |

## Sale PRICE at $0 from PUBLIC records — CORRECTED VERDICT (2026-07-31, Steve was right)
First-pass agent said "no $0 source." WRONG. **Prop 13 makes the assessor the free public price source.**
On a change of ownership, CA reassesses a property to fair market value ≈ the purchase price, and that
becomes the new roll value — official, public, free. Proven in our own 2025 roll (e.g. 21205 Saticoy St,
30 units, recorded 2024-12-31, assessed **$4,980,000** = a real sale price, not a Prop-13-suppressed base).

**The free build:** pull the LA County eGIS assessor rolls for **2021–2025** (same free ArcGIS layer we
already use; we currently hold only 2025) and compute each AIN's **year-over-year assessed-value step-up**.
A material step-up = a reassessment = a change of ownership at market → that year's new value ≈ the SALE
PRICE. Entirely $0, official, from the primary record — this is the assessor half of how ATTOM/CoreLogic
build "last sale," done ourselves.

Cross-checks (also public): **deed DTT** (price ≈ DTT/0.0011, LA base $1.10/$1,000; deed-image access may
cost) and the **property tax bill** (TTC lookup by AIN shows the same assessed value).

**Honest limits:** (a) Prop-19 parent-child transfers don't reassess (excluded — not market sales anyway);
(b) new construction / partial-interest transfers add value-change noise; (c) the **commercial entity-
transfer loophole** (<50% ownership change) dodges reassessment, so some big pure-commercial sales won't
step up — those need deed DTT or a paid feed. Residential + most multifamily = fully recoverable free.

Paid fallback for the commercial gap only: **ATTOM ~$500–2,000/yr** (direct-from-county by AIN). Either
way, drop the Redfin `closed-sales`.

## The B2B product you can build TODAY at $0 data cost (public records + our IP)
A **property + loan intelligence service** for loan officers / brokers / investors ("Frank the loan officer"):
1. **Ownership & parcel intelligence** — search 2.4M LA parcels by owner / address / use / value (assessor).
2. **Loan intelligence + assumable-loan lead engine** — FHA loans (rate, amount, origination) + our
   assumable heuristic → "properties likely carrying a sub-4% assumable loan." Entirely public + our IP.
   This is the killer feature and it's 100% clean.
3. **Licensed agent/broker directory** — sliceable rolodex from the DRE public roll.
4. **Market/demographics context** — Census ACS overlays.
5. **Closed commercial deal-flow** (re-props) — clean ONCE sale price is re-sourced from the Recorder.

## What can NEVER be in the B2B product without a paid license
Live for-sale **listings** (CREXi/Redfin), scraped **closed-sale prices** (Redfin), any restated
MLS/portal listing field. Those stay display-only-with-attribution or link-out-to-broker.