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GET
Verify a GS1 key's check digit and identify its prefix

Query Parameters

key
string
required

The GS1 key to analyse, e.g. 09506000164908. Hyphens and spaces are ignored.

Required string length: 1 - 64

Response

200 - application/json

OK

Check-digit and issuing-organisation analysis of a numeric GS1 key.

value
string
required

The input, echoed back unchanged.

is_valid
boolean
required

True when the key's trailing GS1 mod-10 check digit is correct.

length
integer
required

Digit count after stripping hyphens and spaces.

Required range: x >= 0
Example:

14

is_gtin_length
boolean
required

Whether the length is one of the GTIN-8/12/13/14 lengths.

error
string | null

Why the key is invalid, or null when it checks out.

normalized
string | null

GTIN-length keys zero-padded to GTIN-14; other keys stripped of separators. null when the key could not be read.

check_digit
string | null

The trailing digit supplied by the caller.

Example:

"8"

expected_check_digit
string | null

The digit the GS1 mod-10 algorithm requires. Populated even when it disagrees with check_digit.

gs1_prefix
string | null

The three-digit GS1 prefix (digits 2-4 of the GTIN-14). null for non-GTIN-length keys.

issuing_organization
string | null

Which GS1 Member Organisation or scheme that prefix belongs to. null when unassigned or not GTIN-shaped.