Rate a product by barcode
The very first use case from the original 2014 white book: consumers giving feedback on the products they buy — no store account, no manufacturer's permission. Every product barcode is a URI, and everything with a URI deserves feedback.
Enter or scan a barcode
Type the digits printed under any product barcode (EAN-13, UPC-A, EAN-8 or GTIN-14). The check digit is verified before anything is looked up.
Camera scanning needs Chrome/Android
(the BarcodeDetector API) — typing the digits works everywhere.
No product handy? Try one of these:
Feedback on this product
That URI is a GS1 Digital Link — the product's standard identity on the web — so everyone scanning the same product converges on the same feedback.
How this works
The digits are validated with the standard GS1 mod-10 check digit,
normalized to a 14-digit GTIN, and turned into
https://id.gs1.org/01/<gtin14>. Three shipped widgets are
then bound to that URI — stars on the product itself, comments and tags on
#comments / #tags fragments so the counts never
mix — reading from and publishing to the live server's
/annotations/ endpoint with your self-signed P-256 identity.