About Mercatian
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Mercatian is a radar for the Universal Commerce Protocol: it finds shops that publish a UCP profile, checks that profile every hour, and keeps every response. This page explains how it works and, more importantly, what it does not claim.
How it works
- 01
Discovery
Shops arrive from public UCP registries and from anyone's submission. Where each one came from is recorded, so it is always possible to see why it is on the radar.
- 02
Hourly check
We request /.well-known/ucp from the domain and nothing else. We do not browse the catalogue, do not create carts, and do not touch any purchase endpoint.
- 03
Immutable snapshot
Every response is stored as received, with its timestamp. Nothing is overwritten, which is why a shop's history can be read and checked on its own page.
- 04
Score
The UCP Score is computed from the published profile alone, with fixed and public weights. Same input, same result.
What we verify, and what we do not
This distinction is the product. A UCP profile is a shop's declaration, and we verify the declaration, not the execution.
- That the profile exists, is served, and is valid UCP.
- Which capabilities, transports and payment handlers it declares.
- Whether it publishes signing keys, and which versions it claims.
- When any of that changed, with a timestamp.
- That its checkout actually works: we never complete a purchase.
- That it honours what it declares. Declaring a capability is not serving it.
- Anything about prices, stock, shipping, support or solvency.
- Anything that would require authenticating as that shop's customer.
A high score means a mature profile, not a shop worth buying from. Mercatian endorses no shop and takes no payment to be listed, ranked or scored.
Open data
Everything on the site comes from a public, key-free API and can be cited. If you publish anything based on it, state the date: it changes every hour.
Public API: https://api.mercatian.es/api/stats ↗Who runs it
Mercatian is an independent project operated from Spain. It belongs to no shop on the radar, no e-commerce vendor, and not to the group developing UCP.
Corrections and removals
If you are responsible for a shop on the radar and something is wrong, write to us and we will fix it. If you would rather not appear, we remove it, no reasons asked. Removing a shop deletes its snapshots too.
The tax identification details required by Spanish e-commerce law are pending publication while business registration is completed. We would rather say so than leave it out. For any formal notice, the contact address is valid and monitored.