Gemmai Valuation API

Get AI-powered price estimates for cars, wristwatches, and rings. Send item details and optionally a photo; get back a valuation with price estimate, confidence, and price range.

What can this API do?

Send an item category and its details to get a price estimate. Add a photo URL and the API uses vision to fill in missing attributes before valuing. Use Enrich to preview detected attributes before committing to a valuation.

Feature	What it means
Get a price (valuations)	Send the item type and its details → get an estimated value and a price range.
Use a photo	Send an image URL → the API analyzes it and can fill in attributes (e.g. watch model, strap) and then value the item.
Enrich from image	Get suggested attributes from a photo (e.g. "we think this is steel, black dial") before or instead of asking for a price.
Fetch and compare	Retrieve a past valuation by ID, get similar sales, or see a simple timeline.

Supported item types: car, wristwatch, ring. Call GET /v1/categories for the current full list.

Key concepts

Category — the kind of item: car, wristwatch, or ring. Every valuation or enrich request needs a category.

Attributes — details about the item used to estimate value. They depend on the category. See Attributes for the full list per category.

Vision and fileId — send an image URL to POST /v1/vision → get a fileId → pass that fileId to Enrich or Valuations so the API uses what it "saw" in the photo.

Enrich — fill in attributes using the image and external data. Call POST /v1/enrich with a category and fileId; get back normalizedAttributes you can pass directly to Valuations.

Valuations — get a price estimate. Call POST /v1/valuations with category and attributes. Optionally add a fileId to trigger enrichment first.