Comp pack (paid, priced per pack) — with a FREE preview

The Machine Storefront's comp pack: a subject valuation INDICATED BY comparable sales, wrapped with the comps that prove it. Answers the underwriting question "what is this worth, and which sales prove it?".

The comps are the SAME precomputed comparable_sales the free GET /api/v1/parcels/{id}/comps route serves, with the same read-time similarity_score (0–100) and similarity_components on every comp, plus similarity_basis, similarity_method and comp_set_quality; the subject's valuation fields come from parcels_serving. The indicated value is derived transparently (median comp $/sqft x subject sqft when both are known, else the median comp sale price) with an interquartile range, and is reconstructable from the comps in the same payload -- never a black-box AVM.

PRICE: per pack = clamp($2 x V(subject value) x Q(comp support), $1, $20). Q ramps on the comp count only: the similarity score is served but never priced (decoupled 2026-10-10, prices unchanged). A subject with ZERO precomputed comps has no evidence to support a number and is returned free, never charged. The exact price is advertised in the 402's accepts[0].maxAmountRequired (USDC atomic units, 6 decimals).

FREE PREVIEW: add preview=true for the subject summary, the comp count + median similarity, the exact price, and up to three MASKED comps (parcel/APN withheld, sale price rounded, date to the year). The precise indicated value and the unmasked comps are the paid product.

PAID ACCESS (preview omitted) requires ONE of: (a) x402 pay-per-call via a base64 signed x402 PaymentPayload in the X-PAYMENT header (receipt in X-PAYMENT-RESPONSE); (b) a genuine PAID PropRaven subscription entitlement; (c) anything else -> HTTP 402 whose accepts carries the exact requirements.