We're building Coin Vision, a tool that identifies a coin from a single photo. The technology is only ever as good as the coins it has learned from, and right now most apps lean on thin, repetitive catalogs. That's why they fall apart on the interesting stuff — the very coins collectors actually care about. We think the people who can fix that are collectors themselves. You already have what the model is starving for: real coins, photographed in real conditions, and knowledge about those coins.

We'd love your help in three concrete ways:

1. Upload photos of coins from your collection — obverse and reverse, ordinary lighting is fine.

2. Group them — review what our model (Lucky Coin) grouped, group manually hard cases.

3. Label the Groups — country, denomination, year, mint, variety — as much or as little as you know.