{
  "id": "oas3-operation-summary-title-case",
  "name": "OpenAPI Operation Summary Must Be Title Case",
  "description": "Every OpenAPI operation's summary field must be written in Title Case to keep documentation portals, code generators, and reading experience consistent across the API estate.",
  "message": "Operation summary MUST be Title Case.",
  "rationale": "Mixed casing in summaries breaks documentation rendering and confuses SDK consumers.",
  "severity": "warn",
  "target": "openapi",
  "scope": "design",
  "lifecycle": "design",
  "given": "$.paths[*][get,post,put,patch,delete,options,head].summary",
  "then": {
    "function": "pattern",
    "functionOptions": {
      "match": "^([A-Z][a-z0-9]*)( [A-Z][a-z0-9]*)*$"
    }
  },
  "function": "pattern",
  "conformance": "MUST",
  "engine": "spectral",
  "tags": ["OpenAPI", "Design", "Naming", "Documentation"],
  "guidanceUrl": "https://developer.apievangelist.com/feeds/rules/",
  "owner": "API Governance Working Group",
  "created": "2026-01-15",
  "modified": "2026-05-22",
  "version": "1.0.0",
  "status": "active"
}