PRICE-ANCHORED VALUATION — PUBLIC RESEARCH TEST
Model: price-anchor-shape-v1; browser port: price-anchor-web-v1.
Frozen model/valuation snapshot: 19 October 2026. Public page added 20 October 2026.
Endpoint: POST /api/vehicle-valuation/price-anchor
The earlier /api/vehicle-valuation endpoint is unchanged.

Example request — deliberately hypothetical prices, not researched Ford prices:
{
  "purpose": "research",
  "vehicle": {
    "make": "FORD", "model": "FOCUS", "registration_year": 2018,
    "valuation_date": "2026-10-19", "mileage_miles": 64000,
    "fuel_type": "Petrol", "engine_litres": 1.0
  },
  "anchor": {
    "origin": "hypothetical", "price_low_gbp": 20000, "price_high_gbp": 25000,
    "price_year": 2018, "basis": "uk_list_inc_vat", "market": "UK", "currency": "GBP",
    "source_reference": "Invented example prices; not researched Ford prices"
  }
}

Default purpose is quote: estimate_gbp=null, status=customer_input_required.
Only explicit research purpose returns a scenario. live_quote_ready is false.
Body limit: 8192 characters. Invalid JSON/request/purpose: 400; oversized: 413.
Out-of-scope or unsupported input returns customer_input_required with no estimate.
The approved original-price catalogue is empty; verified_catalogue is rejected.
Accepted anchor origins: hypothetical, customer_supplied (unverified).
Price basis: uk_list_inc_vat or uk_otr_inc_vat; UK/GBP, same registration year.
Unknown makes need vehicle.market_tier = mainstream or premium.
Declared modified/specialist_import/writeoff/classic vehicles are excluded.

Research estimate = supplied original price x monotone age/mileage shape x frozen
market factor. A supplied price range produces a geometric-midpoint estimate and
anchor_sensitivity_gbp; this is NOT a calibrated prediction interval. Both
range_gbp and uncertainty_interval_gbp remain null. Age uses calendar years.
The UI fixes the date to 2026-10-19, does not claim a live market lookup and runs
entirely in the browser. No public feedback is stored or sent automatically.
Testers may choose to copy/download a report or open a mail draft for review.
Reports must be reviewed for provenance, permission, duplicates and dates before
being used as validation or training data. Asking prices and sale prices differ.

Coefficients copied unchanged from the 19 October prototype:
SHA256 c40b225cf5164176395a51bb3e8f500ff9d388cce2e6233a6cce6e1c7a2ba8b3.
66,081 historical training rows; 177 families, nine makes, 47 family curves.
Original-price level calibration incomplete; current individual validation n=0.
The shape is normalised to 1 at zero age/mileage; first-owner discount is not fitted.
Generation, trim, optional equipment and condition are unobserved in the fit.

Sources: Aditya Desai, 100000 UK Used Car Dataset v3, publisher-labelled CC0.
Upstream advert rights not independently established. Derived coefficients only.
ONS D7E9, August 2026 index 109.4, released 16 September 2026; assumed June 2020
base 96.5; market factor 1.133678756476684. Contains public sector information
licensed under the Open Government Licence v3.0. Opening later does not refresh it.
No Autoza factor, current-price leads or paid feed is used by this new calculator.