Skip to main content

GS1 Digital Link

GS1 Digital Link is a standard for encoding GS1 identifiers (GTIN, GLN, etc.) as web URIs. DPP Kit uses GS1 Digital Link for product and facility resolution.

How It Works​

Traditional barcodes encode a number. GS1 Digital Link encodes a web address that can be scanned and resolved:

Traditional barcode:  09347823000029
GS1 Digital Link:     https://resolver.dppkit.io/01/09347823000029

When scanned, the Digital Link resolves to the credential — the Digital Product Passport, Facility Record, or other document associated with that identifier.

URI Structure​

GS1 Digital Link URIs follow a standard path structure using Application Identifiers:

https://{resolver}/{ai}/{value}

Application Identifiers Used by DPP Kit​

AINamePathUsed By
01GTIN/01/{gtin14}DPP, DTE, DCC
414GLN/414/{gln13}DFR, DIA
10Batch/Lot/10/{batch}Serialization
21Serial/21/{serial}Serialization

Examples​

# Look up a product by GTIN
https://resolver.dppkit.io/01/09347823000029

# Look up a facility by GLN
https://resolver.dppkit.io/414/9347823000012

# Look up a specific batch of a product
https://resolver.dppkit.io/01/09347823000029/10/LOT-2024-A

# Look up a specific unit
https://resolver.dppkit.io/01/09347823000029/10/LOT-2024-A/21/UNIT-001

Identity Resolver (IDR)​

DPP Kit runs an Identity Resolver service that implements GS1 Digital Link resolution. When a credential is issued:

  1. The credential is stored in the Storage Service (gets a URL)
  2. The identifier-to-URL mapping is registered in the IDR
  3. Anyone querying the IDR with the identifier gets redirected to the credential

Dual-Response Resolution​

The IDR supports GS1's dual-response pattern:

  • HTML response — For browsers, returns a human-readable credential viewer page
  • JSON response — For machines, returns link metadata for programmatic consumption

The response type is determined by the Accept header or content negotiation.

QR Codes​

GS1 Digital Link URIs can be encoded directly in QR codes. Scanning the QR code opens the resolver URL, which redirects to the credential. This enables:

  • Product packaging with scannable QR codes
  • Facility signage with location QR codes
  • Supply chain documentation with embedded references

Further Reading​