{
  "$schema": "../json-schema/style-guide-rule-schema.json",
  "id": "zalando-101",
  "guide": "style-guides:zalando",
  "level": "MUST",
  "title": "Provide API Specification Using OpenAPI",
  "summary": "Every REST API at Zalando must be specified in OpenAPI. The OpenAPI document is the human- and machine-readable source of truth and is required for consumer review.",
  "category": "Documentation",
  "rationale": "A single specification format makes APIs lintable, mockable, and consumable by SDK generators and gateways without per-team divergence.",
  "appliesTo": ["REST"],
  "sourceUrl": "https://opensource.zalando.com/restful-api-guidelines/#101",
  "references": [
    {
      "url": "https://spec.openapis.org/oas/latest.html",
      "title": "OpenAPI Specification",
      "type": "Spec"
    }
  ],
  "spectralRule": {
    "given": "$",
    "then": { "field": "openapi", "function": "truthy" },
    "severity": "error"
  },
  "relatedRules": ["aip-191"],
  "tags": ["OpenAPI", "Documentation"]
}