{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://knative.dev/schemas/eventing.json",
  "title": "Knative Eventing Resources",
  "description": "JSON Schema for Knative Eventing custom resources including Broker, Trigger, Channel, Subscription, and event sources. These resources enable event-driven architectures on Kubernetes with CloudEvents-compliant event routing and delivery.",
  "type": "object",
  "oneOf": [
    { "$ref": "#/$defs/Broker" },
    { "$ref": "#/$defs/Trigger" },
    { "$ref": "#/$defs/Channel" },
    { "$ref": "#/$defs/Subscription" },
    { "$ref": "#/$defs/ApiServerSource" },
    { "$ref": "#/$defs/PingSource" },
    { "$ref": "#/$defs/SinkBinding" }
  ],
  "$defs": {
    "ObjectMeta": {
      "type": "object",
      "description": "Standard Kubernetes object metadata.",
      "required": ["name"],
      "properties": {
        "name": {
          "type": "string",
          "description": "Unique name of the resource within its namespace.",
          "maxLength": 253
        },
        "namespace": {
          "type": "string",
          "description": "Kubernetes namespace."
        },
        "labels": {
          "type": "object",
          "description": "Key-value labels.",
          "additionalProperties": { "type": "string" }
        },
        "annotations": {
          "type": "object",
          "description": "Non-identifying metadata.",
          "additionalProperties": { "type": "string" }
        }
      }
    },
    "Destination": {
      "type": "object",
      "description": "A CloudEvent delivery destination. Specifies either a Kubernetes resource reference or a direct URI.",
      "oneOf": [
        {
          "required": ["ref"],
          "properties": {
            "ref": {
              "type": "object",
              "description": "Reference to a Kubernetes resource that acts as an addressable destination.",
              "required": ["apiVersion", "kind", "name"],
              "properties": {
                "apiVersion": {
                  "type": "string",
                  "description": "API version of the destination resource."
                },
                "kind": {
                  "type": "string",
                  "description": "Kind of the destination resource, such as Service or Broker."
                },
                "name": {
                  "type": "string",
                  "description": "Name of the destination resource."
                },
                "namespace": {
                  "type": "string",
                  "description": "Namespace of the destination resource."
                }
              }
            }
          }
        },
        {
          "required": ["uri"],
          "properties": {
            "uri": {
              "type": "string",
              "format": "uri",
              "description": "Direct URI to deliver events to."
            }
          }
        }
      ]
    },
    "DeliverySpec": {
      "type": "object",
      "description": "Retry and dead-letter delivery configuration.",
      "properties": {
        "deadLetterSink": {
          "$ref": "#/$defs/Destination",
          "description": "Destination for events that fail delivery after all retries."
        },
        "retry": {
          "type": "integer",
          "minimum": 0,
          "description": "Minimum number of retries before sending to dead-letter sink."
        },
        "backoffPolicy": {
          "type": "string",
          "enum": ["linear", "exponential"],
          "description": "Strategy for spacing retries. Linear uses a fixed interval; exponential doubles each retry."
        },
        "backoffDelay": {
          "type": "string",
          "pattern": "^PT?[0-9]+(\\.[0-9]+)?[SMHDWY]$",
          "description": "ISO 8601 duration for the delay between retries, for example PT2S for 2 seconds."
        },
        "timeout": {
          "type": "string",
          "description": "ISO 8601 duration timeout per delivery attempt."
        }
      }
    },
    "Broker": {
      "type": "object",
      "description": "A Knative Broker that accepts CloudEvents and routes them to matching Triggers based on attribute filters.",
      "required": ["apiVersion", "kind", "metadata"],
      "properties": {
        "apiVersion": {
          "type": "string",
          "const": "eventing.knative.dev/v1",
          "description": "API version for the Broker."
        },
        "kind": {
          "type": "string",
          "const": "Broker",
          "description": "Resource kind identifier."
        },
        "metadata": { "$ref": "#/$defs/ObjectMeta" },
        "spec": {
          "type": "object",
          "description": "Broker specification.",
          "properties": {
            "config": {
              "type": "object",
              "description": "Optional reference to a ConfigMap configuring the Broker's backing implementation.",
              "properties": {
                "apiVersion": {
                  "type": "string",
                  "description": "API version of the config resource."
                },
                "kind": {
                  "type": "string",
                  "description": "Kind of the config resource."
                },
                "name": {
                  "type": "string",
                  "description": "Name of the config resource."
                }
              }
            },
            "delivery": { "$ref": "#/$defs/DeliverySpec" }
          }
        }
      }
    },
    "Trigger": {
      "type": "object",
      "description": "A Knative Trigger that subscribes to events from a Broker with optional attribute filters and routes matching events to a destination.",
      "required": ["apiVersion", "kind", "metadata", "spec"],
      "properties": {
        "apiVersion": {
          "type": "string",
          "const": "eventing.knative.dev/v1",
          "description": "API version for the Trigger."
        },
        "kind": {
          "type": "string",
          "const": "Trigger",
          "description": "Resource kind identifier."
        },
        "metadata": { "$ref": "#/$defs/ObjectMeta" },
        "spec": {
          "type": "object",
          "description": "Trigger specification.",
          "required": ["broker", "subscriber"],
          "properties": {
            "broker": {
              "type": "string",
              "description": "Name of the Broker this Trigger subscribes to."
            },
            "filter": {
              "type": "object",
              "description": "Filter for selecting events by CloudEvent attribute values.",
              "properties": {
                "attributes": {
                  "type": "object",
                  "description": "Map of CloudEvent attribute names to exact match values. Events must match all specified attributes.",
                  "additionalProperties": { "type": "string" }
                }
              }
            },
            "subscriber": { "$ref": "#/$defs/Destination" },
            "delivery": { "$ref": "#/$defs/DeliverySpec" }
          }
        }
      }
    },
    "Channel": {
      "type": "object",
      "description": "A Knative Channel providing a generic pub/sub interface that fans events out to all Subscriptions.",
      "required": ["apiVersion", "kind", "metadata"],
      "properties": {
        "apiVersion": {
          "type": "string",
          "const": "messaging.knative.dev/v1",
          "description": "API version for the Channel."
        },
        "kind": {
          "type": "string",
          "const": "Channel",
          "description": "Resource kind identifier."
        },
        "metadata": { "$ref": "#/$defs/ObjectMeta" },
        "spec": {
          "type": "object",
          "description": "Channel specification.",
          "properties": {
            "channelTemplate": {
              "type": "object",
              "description": "Specifies the Channel implementation type to use.",
              "properties": {
                "apiVersion": {
                  "type": "string",
                  "description": "API version of the channel implementation."
                },
                "kind": {
                  "type": "string",
                  "description": "Kind of the channel implementation such as InMemoryChannel or KafkaChannel."
                },
                "spec": {
                  "type": "object",
                  "description": "Implementation-specific channel configuration."
                }
              }
            },
            "delivery": { "$ref": "#/$defs/DeliverySpec" }
          }
        }
      }
    },
    "Subscription": {
      "type": "object",
      "description": "A Knative Subscription routing events from a Channel to a subscriber with optional reply forwarding and dead-letter sink.",
      "required": ["apiVersion", "kind", "metadata", "spec"],
      "properties": {
        "apiVersion": {
          "type": "string",
          "const": "messaging.knative.dev/v1",
          "description": "API version for the Subscription."
        },
        "kind": {
          "type": "string",
          "const": "Subscription",
          "description": "Resource kind identifier."
        },
        "metadata": { "$ref": "#/$defs/ObjectMeta" },
        "spec": {
          "type": "object",
          "description": "Subscription specification.",
          "required": ["channel"],
          "properties": {
            "channel": {
              "type": "object",
              "description": "Reference to the Channel to subscribe to.",
              "required": ["name"],
              "properties": {
                "apiVersion": {
                  "type": "string",
                  "description": "API version of the Channel resource."
                },
                "kind": {
                  "type": "string",
                  "description": "Kind of the Channel resource."
                },
                "name": {
                  "type": "string",
                  "description": "Name of the Channel."
                }
              }
            },
            "subscriber": { "$ref": "#/$defs/Destination" },
            "reply": { "$ref": "#/$defs/Destination" },
            "delivery": { "$ref": "#/$defs/DeliverySpec" }
          }
        }
      }
    },
    "ApiServerSource": {
      "type": "object",
      "description": "A Knative ApiServerSource that watches Kubernetes API server events for specified resource types and emits them as CloudEvents to a sink.",
      "required": ["apiVersion", "kind", "metadata", "spec"],
      "properties": {
        "apiVersion": {
          "type": "string",
          "const": "sources.knative.dev/v1",
          "description": "API version for the ApiServerSource."
        },
        "kind": {
          "type": "string",
          "const": "ApiServerSource",
          "description": "Resource kind identifier."
        },
        "metadata": { "$ref": "#/$defs/ObjectMeta" },
        "spec": {
          "type": "object",
          "description": "ApiServerSource specification.",
          "required": ["resources", "sink"],
          "properties": {
            "resources": {
              "type": "array",
              "description": "Kubernetes API resource types to watch.",
              "minItems": 1,
              "items": {
                "type": "object",
                "required": ["apiVersion", "kind"],
                "properties": {
                  "apiVersion": {
                    "type": "string",
                    "description": "API version of the resource to watch, such as v1 or apps/v1."
                  },
                  "kind": {
                    "type": "string",
                    "description": "Kind of the resource to watch, such as Pod, Deployment, or ConfigMap."
                  },
                  "selector": {
                    "type": "object",
                    "description": "Label selector to filter watched resources.",
                    "properties": {
                      "matchLabels": {
                        "type": "object",
                        "additionalProperties": { "type": "string" }
                      }
                    }
                  }
                }
              }
            },
            "sink": { "$ref": "#/$defs/Destination" },
            "serviceAccountName": {
              "type": "string",
              "description": "Service account with RBAC permissions to watch the listed resource types."
            },
            "mode": {
              "type": "string",
              "enum": ["Reference", "Resource"],
              "description": "Reference sends only resource identifiers; Resource sends full resource bodies."
            }
          }
        }
      }
    },
    "PingSource": {
      "type": "object",
      "description": "A Knative PingSource that emits CloudEvents on a cron schedule with a configurable payload.",
      "required": ["apiVersion", "kind", "metadata", "spec"],
      "properties": {
        "apiVersion": {
          "type": "string",
          "const": "sources.knative.dev/v1",
          "description": "API version for the PingSource."
        },
        "kind": {
          "type": "string",
          "const": "PingSource",
          "description": "Resource kind identifier."
        },
        "metadata": { "$ref": "#/$defs/ObjectMeta" },
        "spec": {
          "type": "object",
          "description": "PingSource specification.",
          "required": ["schedule", "sink"],
          "properties": {
            "schedule": {
              "type": "string",
              "pattern": "^(\\*|[0-9,-/]+)\\s+(\\*|[0-9,-/]+)\\s+(\\*|[0-9,-/]+)\\s+(\\*|[0-9,-/]+)\\s+(\\*|[0-9,-/]+)$",
              "description": "Cron schedule expression, for example */5 * * * * fires every five minutes."
            },
            "data": {
              "type": "string",
              "description": "Event payload data sent with each fired CloudEvent."
            },
            "dataContentType": {
              "type": "string",
              "default": "application/json",
              "description": "Content type of the data field."
            },
            "timezone": {
              "type": "string",
              "description": "IANA timezone name for interpreting the cron schedule, such as America/New_York."
            },
            "sink": { "$ref": "#/$defs/Destination" }
          }
        }
      }
    },
    "SinkBinding": {
      "type": "object",
      "description": "A Knative SinkBinding that injects the sink URI as K_SINK environment variable into a PodSpecable workload.",
      "required": ["apiVersion", "kind", "metadata", "spec"],
      "properties": {
        "apiVersion": {
          "type": "string",
          "const": "sources.knative.dev/v1",
          "description": "API version for the SinkBinding."
        },
        "kind": {
          "type": "string",
          "const": "SinkBinding",
          "description": "Resource kind identifier."
        },
        "metadata": { "$ref": "#/$defs/ObjectMeta" },
        "spec": {
          "type": "object",
          "description": "SinkBinding specification.",
          "required": ["subject", "sink"],
          "properties": {
            "subject": {
              "type": "object",
              "description": "Reference to the PodSpecable workload to augment with K_SINK.",
              "required": ["apiVersion", "kind", "name"],
              "properties": {
                "apiVersion": {
                  "type": "string",
                  "description": "API version of the workload, such as apps/v1."
                },
                "kind": {
                  "type": "string",
                  "description": "Kind of the workload, such as Deployment, StatefulSet, or Job."
                },
                "name": {
                  "type": "string",
                  "description": "Name of the workload."
                },
                "namespace": {
                  "type": "string",
                  "description": "Namespace of the workload."
                }
              }
            },
            "sink": { "$ref": "#/$defs/Destination" },
            "ceOverrides": {
              "type": "object",
              "description": "CloudEvent extension attributes to inject into all events sent by the subject.",
              "properties": {
                "extensions": {
                  "type": "object",
                  "description": "Extension attribute key-value pairs.",
                  "additionalProperties": { "type": "string" }
                }
              }
            }
          }
        }
      }
    }
  }
}