Offline validation of product barcode numbers: EAN-8, UPC-A, EAN-13 and GTIN-14, using the GS1 mod-10 weighted checksum. Catches corrupted GTINs in supplier catalogs before marketplace publication (Amazon/Google reject invalid GTINs). Query: ?gtin=4006381333931. Returns valid flag, detected format, GS1 member-org prefix and the computed check digit. Deterministic, cached 1 year.
| Network | Scheme | Amount | Pay To |
|---|---|---|---|
| Base | exact | $0.001000 USDC | 0x6ab8...2dff |