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The Closient Resolver implements the GS1 Digital Link standard, enabling any GTIN to be resolved to structured product data via a standard URI format. Resolution behavior is configurable through rules that support time-based routing, scope hierarchy, and custom destinations.

URI Format

A GS1 Digital Link URI encodes a primary identifier and optional qualifiers as path segments:
https://www.closient.com/01/{gtin}
https://www.closient.com/01/{gtin}/10/{lot}/21/{serial}

Supported Application Identifiers

AINameExampleDescription
01GTIN00012345678905Primary product identifier
00SSCC123456789012345678Shipping container code
10Batch/LotABC123Production batch
21SerialSN001Individual item serial
17Expiry261231Expiry date (YYMMDD)
414GLN (Party)1234567890123Party identifier
417GLN (Location)1234567890123Location identifier

Content Negotiation

The resolver returns different formats based on the Accept header:
Accept HeaderResponse
application/jsonJSON product data (default)
application/linkset+jsonGS1 Linkset JSON
text/htmlHTML redirect to product information page

Resolution Rules

Resolution behavior is controlled through rules configured per organization. Rules determine where a Digital Link request is routed.

Scope Hierarchy

Rules are evaluated from most specific to least specific scope. The first matching rule wins:
PriorityScopeMatches
1 (highest)SerialSpecific serial number within a product
2BatchSpecific batch/lot within a product
3ProductA specific GTIN
4BrandAll products under a brand
5 (lowest)OrganizationAll products in the organization
Within each scope, rules are ordered by order_index (lower = higher priority).

Destination Types

TypeBehavior
HOSTED_PAGERedirect to Closient-hosted product information page
CUSTOM_URLRedirect to your own URL
For custom URLs, configure fallback behavior when the URL is unreachable:
  • Skip rule — evaluate the next rule in priority order
  • Fallback to hosted — use the Closient hosted page instead
Custom URL health is monitored automatically with consecutive failure tracking.

Time-Based Routing

Rules support time criteria for conditional routing (all criteria are AND-ed when present):
CriteriaFormatExample
Absolute windowUTC datetimes2026-01-01 to 2026-12-31
Annual windowMM-DD (supports year wrap)11-01 to 02-28 (holiday season)
Day of week0=Monday through 6=Sunday[0, 1, 2, 3, 4] (weekdays only)
Time of dayHH:MM09:00 to 17:00
Time criteria use the organization’s configured routing timezone (IANA format, e.g., America/New_York). Rules can be scoped to specific GS1 link types:
Link TypeDescription
gs1:pipProduct information page
gs1:certificationInfoCertifications and compliance
gs1:sustainabilityInfoSustainability data
gs1:recipeInfoIngredients and recipes
gs1:traceabilitySupply chain traceability

GS1 Conformance

The Closient Resolver is designed to conform to the GS1 Digital Link standard, including proper handling of Accept headers, Link response headers, and linkset JSON format. A built-in conformance test suite is available for validation. See the Resolver API reference for full endpoint documentation.