Data Formats

EUlabel outputs passport data in formats aligned with GS1 standards, EU regulatory requirements, and web interoperability best practices.

At a glance

JSON-LD

Structured passport datasets for regulators, search engines, and interoperability

Linkset

Discoverable link collections returned by the resolver (RFC 9264)

OpenAPI

The API contract that powers the reference docs and SDK generation

JSON-LD: Primary passport format

Product passport data is serialized as JSON-LD using schema.org as the semantic anchor, extended with GS1 Web Vocabulary terms where schema.org lacks coverage.

JSON-LD ensures that passport data is:

Machine-readable by search engines, AI agents, and regulatory systems
Interoperable across platforms without proprietary data mappings
Discoverable when embedded in HTML pages

Example: Wine passport as JSON-LD

{
  "@context": ["https://schema.org", "https://www.gs1.org/voc/"],
  "@type": "Product",
  "name": "Quinta dos Carvalhais Alfrocheiro 2019",
  "gtin": "05601012012200",
  "brand": {
    "@type": "Brand",
    "name": "Quinta dos Carvalhais"
  },
  "countryOfOrigin": {
    "@type": "Country",
    "name": "Portugal"
  },
  "hasIngredientList": [
    {
      "@type": "gs1:FoodBeverageTobaccoIngredientDetails",
      "ingredientName": "Grapes (Alfrocheiro)",
      "ingredientContentPercentage": 99.986
    },
    {
      "@type": "gs1:FoodBeverageTobaccoIngredientDetails",
      "ingredientName": "Sulphites",
      "ingredientContentPercentage": 0.014
    }
  ],
  "hasAllergen": [
    {
      "@type": "gs1:AllergenDetails",
      "allergenType": "https://gs1.org/voc/AllergenTypeCode-AS",
      "allergenLevelOfContainment": "CONTAINS"
    }
  ],
  "nutritionInformation": {
    "@type": "NutritionInformation",
    "servingSize": "100 mL",
    "calories": "84 kcal",
    "fatContent": "0 g",
    "carbohydrateContent": "1 g",
    "sugarContent": "0.1 g",
    "proteinContent": "0 g",
    "sodiumContent": "0 g"
  }
}

If you’re embedding passport data in your own pages, JSON-LD is the most portable representation: it works across regulatory systems and web tooling.

Content negotiation

Request Accept: application/ld+json from the passport endpoint to receive JSON-LD instead of the default JSON response:

export EULABEL_API_KEY="sk_test_..."

curl https://api.eulabel.eu/v1/products/a1b2c3d4-.../passport \
  -H "Authorization: Bearer $EULABEL_API_KEY" \
  -H "Accept: application/ld+json"

Embedding in HTML

Structured data is embedded in passport web pages using a <script> tag, invisible to consumers but discoverable by machines:

<script type="application/ld+json">
  {
    "@context": "https://schema.org",
    "@type": "Product",
    "name": "Quinta dos Carvalhais Alfrocheiro 2019",
    "gtin": "05601012012200"
  }
</script>

This satisfies two requirements simultaneously: a human-readable passport page for consumers and a machine-readable dataset for regulators and search engines.

Linkset: machine-discoverable links

Use a linkset when you want to discover what resources exist for a product (product page, nutrition section, allergen section, compliance datasets) in a single request.

Guide: Linkset (RFC 9264)
Resolver behavior: How the Resolver Works

OpenAPI: API contract

EUlabel publishes an OpenAPI 3.1 spec that powers this documentation and the SDK generators.

Reference: API Reference
SDKs: SDK Overview