GS1 Resolver

The GS1 resolver is the public read surface for a DPP. The canonical URLs look like this:

https://qr3.app/01/{GTIN}
https://qr3.app/01/{GTIN}/10/{LOT}
https://qr3.app/01/{GTIN}/21/{SERIAL}
https://qr3.app/01/{GTIN}/10/{LOT}/21/{SERIAL}

serial and lot must use safe GS1 path segments only: A-Z, a-z, 0-9, ., _, ~, -, with a length of 1 to 20 characters. Reserved URL separators are rejected so the canonical link stays resolvable.

Content negotiation

The same resolver returns different representations depending on the Accept header:

Accept	Response
`text/html`	consumer HTML
`application/ld+json`	JSON-LD
`application/json`	raw DPP JSON
`application/linkset+json`	linkset with alternates

Public routes

GET /01/... is the canonical resolver
GET /dpp/:gtin/:serial?lot=... is an HTML alias
GET /v1/dpp/:id/qr.svg serves SVG
GET /v1/dpp/:id/qr.png serves PNG
GET /v1/dpp/:id/qr.pdf serves PDF
GET /v1/dpp/:id/qr.eps serves EPS

QR asset visibility follows the DPP status:

live is public without authentication
draft and archived require a valid auth context plus workspace access
Invalid auth returns 401
Non-visible or foreign-workspace passports return 404

Fallback

If qr3.app cannot find a match, the request is forwarded to the upstream GS1 resolver. That keeps printed codes useful even before a product exists locally.

Practical flow

Create the DPP in the dashboard.
Use the GS1 URI as the QR target.
Let consuming systems request the representation they need via Accept.