Compose a GS1 Digital Link URI from Application Identifiers
Build a spec-ordered Digital Link URI from a primary key plus optional qualifiers and data attributes, and grade the result.
Qualifiers and attributes are repeated query parameters in code:value form — ?qualifier=10:LOT1&qualifier=21:SN1&attribute=17:261231 — which keeps the whole request in the URL and therefore cacheable. A token missing its : is reported as an error issue rather than dropped, so a URI is never silently composed without data you asked for.
Keyless — no API key, no signup. IP-throttled at 300 requests/minute and cached at the edge for 24h, so repeat calls for the same input do not reach origin. Over-rate callers get a 429 with a Retry-After header and a retry_after field — it never silently degrades or returns a wrong answer under load.
Query Parameters
The primary identifier AI code, e.g. 01 for GTIN.
2 - 4The primary identifier's value, e.g. 09506000164908.
1 - 256Repeatable qualifier AI in code:value form, e.g. 10:LOT1.
Repeatable data-attribute AI in code:value form, e.g. 17:261231.
URI scheme; http or https. Anything else is reported as an issue and the default is used.
16Resolver host to compose against, e.g. id.gs1.org.
255Response
OK
A composed Digital Link URI plus how it graded.
True when the composed URI carries no error-severity issues.
The scheme actually used (normalised; defaults apply when input was blank).
The host actually used (normalised; defaults apply when input was blank).
The composed URI, or null when the inputs were too incomplete to compose one.
Every issue found while composing.
The primary identifier AI, or null when none was supplied.
Qualifier AIs written into the path.
Data attributes written into the query string.
Which qualifier AI codes this primary key permits — use it to drive a picker.