Docs · Validators

`gtin` validator

GS1 GTIN-8/12/13/14 with trailing-digit checksum.

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One of 19 validator types · pure compute, no AI cost

Reference

Format

Strips whitespace, then matches 8, 12, 13, or 14 digits and verifies the GS1 mod-10 trailing-digit checksum.

Examples

7613034626844 (GTIN-13, EAN)
00012345600012 (GTIN-14, SSCC-style)
0123456789012 (GTIN-13 with leading zero — keep as string!)

How it runs

Implementation

A faithful summary of lib/validators.ts. Validators are pure functions and run identically in the Worker, the Workbench and the MCP server — one implementation, so the three cannot disagree about whether a value is valid.

lib/validators.ts

function validGtin(value) {
  const v = value.replace(/\s+/g, '')
  if (!/^\d{8}$|^\d{12,14}$/.test(v)) {
    return fail('gtin_format', 'expected 8/12/13/14 digits')
  }
  const digits = v.split('').map(Number)
  const check = digits.pop()
  const sum = digits.reverse().reduce(
    (acc, d, i) => acc + d * (i % 2 === 0 ? 3 : 1), 0,
  )
  const want = (10 - (sum % 10)) % 10
  return check === want ? OK : fail('gtin_checksum', 'bad GTIN checksum')
}

Config

Use in a template

Validators attach to a field on a custom template. The cascade runs them after mapping but before commit; failures surface in the per-row validation report.

template.yaml

fields:
  - column: gtin
    type: string
    validators:
      - type: gtin

Watch out

Common gotchas

Leading zeros are significant. Always send GTINs as strings — Excel/JSON parsers that coerce to number will silently drop them and fail the format check.
GTIN-11 is intentionally not accepted (not a GS1 form). GTIN-9, 10 are also rejected.
The reserved Restricted Circulation range (RCN) passes if the checksum is valid; we do not flag GS1 prefix semantics.

Where it runs

Three routes, no AI cost.

POST/v1/validate-rowValidate one row against a template. Stateless, no key, pure compute — the fastest way to try gtin against a real value.no key
POST/v1/uploads/:id/validateRun every field validator over the parsed upload, without committing. Returns errors and warnings per row.read
POST/v1/uploads/:id/commitValidates on the way out. skip_invalid_rows drops the failures instead of failing the commit.commit

Validators are pure functions, so they add nothing to the AI bill. Every map draws a small flat per-map fee from your prepaid token wallet ($10 minimum, shared across the phi-cloud suite); only columns that reach the metered LLM layer, plus any-to-any convert and structural reshape, bill real AI tokens. See pricing

Catalogue

Related templates

Drug formularydrug_formulary_v1
ATC/GTIN-coded drug catalog. Emits FHIR Medication.
Fields · gtin
Supplier inventorysupplier_inventory_v1
Supplier catalogue with GTIN/IBAN/GLN.
Fields · gtin
Productsproducts_v1
Product catalog: SKU, GTIN, price, category, weight, stock flag.
Fields · gtin

Explore

All 19 validator types

The complete list a template field can declare. There is no SNOMED validator — it required an affiliate licence, no template used it, and it was removed in 2026.

Back to the documentation index or browse the template catalogue.

Ready when you are

Validate every row — before it lands.

Attach checksum-strict validators to any field, and gate risky commits behind the requires_hitl flag. One key runs the whole cascade.

Get an API key See pricing

Prepaid token wallet · schema-only data-minimization mode · no free tier

gtin validator