Every dot needs a source.

1. Identify the exact product

We maintain a canonical product record independently from retailer listings. GTINs, model numbers and retailer product codes are retained with their source, observation time and validation outcome.

2. Match retailer offers conservatively

An offer is attached only when identifier or exact-model evidence is strong enough. Ambiguous evidence is rejected or sent for review instead of being silently accepted.

3. Append observations

A successful collection records the observed item price, delivery price when known, availability, currency, retailer, source and timestamp. Money is stored in integer pence.

4. Preserve gaps and failures

A failed collection run is stored as a failure. It does not create a price, overwrite the last successful observation or imply that an item is out of stock.

5. Make recommendations only when justified

One observation is a starting point, not a trend. Historical lows, comparisons and buy-or-wait recommendations will appear only after sufficient genuine observations exist.

Current coverage

The first catalogue contains 13 portable air conditioners. Its initial Currys observations were manually reconciled from the supplied project research. Each was out of stock when observed, so none is presented as a currently purchasable offer.