A market-position endpoint for used vehicles.

Ask it about one car and it answers with that car's standing in its local market — not a page of rows for you to reduce yourself.

Endpoints

GET/v1/valuation Where one vehicle sits: percentile, rank, price band, days-supply, and a confidence object naming which dimension had to be relaxed to find the comparables.

GET/v1/comps The comparable vehicles behind that answer. Thin factual rows, each naming its dealership and linking to that dealership's own listing.

GET/v1/health When the archive was last updated, and per-county coverage. Fails loudly rather than serving stale numbers quietly.

What a valuation looks like

GET /v1/valuation?vin=1C4RJFBG5KC…&mileage=68400&zip=48307

{
  "ask": {
    "percentile": 22,
    "rank": 7,
    "of_n": 23,
    "median_at_mileage": 28480,
    "p25": 26400,
    "p75": 30900
  },
  "days_on_market": { "median": 34, "basis": "listing-clearance" },
  "confidence": {
    "tier": "high",
    "n": 23,
    "radius_mi": 20,
    "relaxed_dimension": null
  },
  "as_of": "2026-09-04",
  "disclaimer": "Asking prices from public listings. Not transaction data."
}

Two things that are unusual, on purpose

A refusal is a 200, never a 404. Under five comparable vehicles you get {"ask": null, "reason": "insufficient_comps", "n": 3, "comps": [...]}. A machine handles a structured refusal far better than an error, and "we do not know" is a real answer that deserves a real response body.
It answers a question rather than selling rows. Listing APIs hand you vehicles and leave the statistics to you. This one does the comparable selection, the mileage adjustment and the confidence assessment, and tells you what it relaxed to get there.

Terms, plainly

Derived figures — percentiles, medians, counts, indices — are yours to display to your own users on the tier that permits it.
Comparable rows carry attribution and a link, and must keep both wherever they are shown.
Photographs and dealers' written descriptions are never collected, so they are never served. Neither is anyone's personal information.

If you are building something that would use this — a CRM, a marketplace, an appraisal tool, an agent — write to hello@lotclock.io and say what shape you need. The contract is easier to change now than after anyone depends on it.