Crossplane CompositeResourceDefinition (XRD)

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://github.com/api-evangelist/crossplane/blob/main/xrd-schema.json",
  "title": "Crossplane CompositeResourceDefinition (XRD)",
  "description": "Schema for a Crossplane CompositeResourceDefinition that defines the API schema for composite resources and optional claims, extending the Kubernetes API with custom infrastructure abstractions.",
  "type": "object",
  "required": ["apiVersion", "kind", "metadata", "spec"],
  "properties": {
    "apiVersion": {
      "type": "string",
      "const": "apiextensions.crossplane.io/v1",
      "description": "API version for the Crossplane XRD resource."
    },
    "kind": {
      "type": "string",
      "const": "CompositeResourceDefinition",
      "description": "Resource kind identifier."
    },
    "metadata": {
      "type": "object",
      "description": "Standard Kubernetes object metadata.",
      "required": ["name"],
      "properties": {
        "name": {
          "type": "string",
          "description": "Name of the XRD, conventionally in the format 'xplural.group'.",
          "pattern": "^x[a-z]+\\.[a-z]+(\\.[a-z]+)*$"
        },
        "labels": {
          "type": "object",
          "description": "Key-value pairs for organizing XRDs.",
          "additionalProperties": { "type": "string" }
        },
        "annotations": {
          "type": "object",
          "description": "Non-identifying metadata.",
          "additionalProperties": { "type": "string" }
        }
      }
    },
    "spec": {
      "type": "object",
      "description": "Specification for the CompositeResourceDefinition.",
      "required": ["group", "names", "versions"],
      "properties": {
        "group": {
          "type": "string",
          "description": "API group for the composite resource, typically a domain name.",
          "pattern": "^[a-z]+(\\.[a-z]+)+$"
        },
        "names": {
          "type": "object",
          "description": "Names to use for the composite resource type.",
          "required": ["kind", "plural"],
          "properties": {
            "kind": {
              "type": "string",
              "description": "PascalCase singular kind for the composite resource.",
              "pattern": "^X[A-Z][a-zA-Z]*$"
            },
            "plural": {
              "type": "string",
              "description": "Lowercase plural name for API discovery.",
              "pattern": "^x[a-z]+$"
            },
            "singular": {
              "type": "string",
              "description": "Lowercase singular name."
            },
            "shortNames": {
              "type": "array",
              "description": "Short aliases for the composite resource.",
              "items": { "type": "string" }
            },
            "listKind": {
              "type": "string",
              "description": "Name of the list kind."
            },
            "categories": {
              "type": "array",
              "description": "Categories the composite resource belongs to.",
              "items": { "type": "string" }
            }
          }
        },
        "claimNames": {
          "type": "object",
          "description": "Names to use for the namespace-scoped claim resource. If omitted, no claim is generated.",
          "required": ["kind", "plural"],
          "properties": {
            "kind": {
              "type": "string",
              "description": "PascalCase singular kind for the claim."
            },
            "plural": {
              "type": "string",
              "description": "Lowercase plural name for the claim."
            },
            "singular": {
              "type": "string",
              "description": "Lowercase singular name for the claim."
            },
            "shortNames": {
              "type": "array",
              "description": "Short aliases for the claim.",
              "items": { "type": "string" }
            },
            "categories": {
              "type": "array",
              "description": "Categories the claim belongs to.",
              "items": { "type": "string" }
            }
          }
        },
        "connectionSecretKeys": {
          "type": "array",
          "description": "Keys that the composite resource and its claims expect in their connection secrets.",
          "items": { "type": "string" }
        },
        "defaultCompositeDeletePolicy": {
          "type": "string",
          "enum": ["Background", "Foreground"],
          "description": "Default delete policy for composite resources."
        },
        "defaultCompositionRef": {
          "type": "object",
          "description": "Default Composition to use when none is specified.",
          "required": ["name"],
          "properties": {
            "name": {
              "type": "string",
              "description": "Name of the default Composition."
            }
          }
        },
        "defaultCompositionUpdatePolicy": {
          "type": "string",
          "enum": ["Automatic", "Manual"],
          "description": "Default update policy for Composition revisions."
        },
        "enforcedCompositionRef": {
          "type": "object",
          "description": "Composition that must always be used, overriding user selection.",
          "required": ["name"],
          "properties": {
            "name": {
              "type": "string",
              "description": "Name of the enforced Composition."
            }
          }
        },
        "versions": {
          "type": "array",
          "description": "Versions of the composite resource API.",
          "minItems": 1,
          "items": {
            "type": "object",
            "required": ["name", "served", "referenceable", "schema"],
            "properties": {
              "name": {
                "type": "string",
                "description": "Version name, e.g. 'v1alpha1', 'v1beta1', 'v1'."
              },
              "served": {
                "type": "boolean",
                "description": "Whether this version is served by the API server."
              },
              "referenceable": {
                "type": "boolean",
                "description": "Whether this version can be referenced by Compositions."
              },
              "deprecated": {
                "type": "boolean",
                "description": "Whether this version is deprecated."
              },
              "deprecationMessage": {
                "type": "string",
                "description": "Message shown when this deprecated version is used."
              },
              "schema": {
                "type": "object",
                "description": "OpenAPI v3 schema for the composite resource spec.",
                "required": ["openAPIV3Schema"],
                "properties": {
                  "openAPIV3Schema": {
                    "type": "object",
                    "description": "OpenAPI v3 schema definition for the composite resource.",
                    "properties": {
                      "type": {
                        "type": "string",
                        "const": "object"
                      },
                      "properties": {
                        "type": "object",
                        "description": "Properties of the composite resource spec."
                      },
                      "required": {
                        "type": "array",
                        "items": { "type": "string" }
                      },
                      "description": {
                        "type": "string"
                      }
                    }
                  }
                }
              },
              "additionalPrinterColumns": {
                "type": "array",
                "description": "Additional columns to display in kubectl output.",
                "items": {
                  "type": "object",
                  "required": ["name", "type", "jsonPath"],
                  "properties": {
                    "name": { "type": "string" },
                    "type": { "type": "string" },
                    "jsonPath": { "type": "string" },
                    "description": { "type": "string" }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}