Events · Schema

Event Source

Descriptor for an event-emitting system: a Kafka topic, a Pulsar tenant/namespace/topic, an EventBridge bus, an Event Grid topic, a Pub/Sub topic, an MQTT topic, or any system that produces CloudEvents. Captures identity, transport, broker, schema, and the CloudEvents 'source' attribute the system stamps onto outbound events.

EventEvent-DrivenEvent StreamingMessagingPub-SubBrokersCloudEventsAsyncAPITopic

Properties

Name Type Description
id string Stable identifier for the event source within the catalog.
name string Human-readable name (e.g. 'orders.placed' or 'aws.s3.objectCreated').
description string What this source emits and the business context for the events.
broker string The broker or messaging platform hosting this source.
protocol string Wire protocol used to publish and consume from this source.
transportEndpoint string Connection URL or bootstrap endpoint (e.g. kafka://broker:9092, mqtts://broker:8883, https://eventgrid.example/api/events).
topicOrChannel string Broker-specific identifier — Kafka topic, Pulsar topic, NATS subject, MQTT topic filter, EventBridge bus name, Event Grid topic name, Pub/Sub topic ID.
partitionCount integer Partition count for log-based brokers (Kafka, Pulsar, Redpanda).
retention object Retention policy for stored events.
deliveryGuarantee string End-to-end delivery semantics this source offers consumers.
orderingScope string Where order is preserved. 'partition' for Kafka, 'key' for Pub/Sub ordering keys, 'global' for Pulsar single-partition or NATS single-stream.
cloudEventsSource string Value this source will stamp into the CloudEvents 'source' attribute on emitted events. SHOULD be unique across the event catalog.
cloudEventsTypes array CloudEvents 'type' values produced by this source.
schemaRegistry object Schema registry binding for payloads emitted on this source.
asyncApi string URL to an AsyncAPI document that documents this source.
owner object Team or service that owns the source.
tags array
View JSON Schema on GitHub

JSON Schema

events-event-source-schema.json Raw ↑
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://api-evangelist.github.io/events/json-schema/events-event-source-schema.json",
  "title": "Event Source",
  "description": "Descriptor for an event-emitting system: a Kafka topic, a Pulsar tenant/namespace/topic, an EventBridge bus, an Event Grid topic, a Pub/Sub topic, an MQTT topic, or any system that produces CloudEvents. Captures identity, transport, broker, schema, and the CloudEvents 'source' attribute the system stamps onto outbound events.",
  "type": "object",
  "required": ["id", "name", "broker", "protocol", "cloudEventsSource"],
  "properties": {
    "id": {
      "type": "string",
      "minLength": 1,
      "description": "Stable identifier for the event source within the catalog."
    },
    "name": {
      "type": "string",
      "description": "Human-readable name (e.g. 'orders.placed' or 'aws.s3.objectCreated')."
    },
    "description": {
      "type": "string",
      "description": "What this source emits and the business context for the events."
    },
    "broker": {
      "type": "string",
      "enum": [
        "Apache Kafka",
        "Apache Pulsar",
        "NATS",
        "Redpanda",
        "IBM MQ",
        "AWS EventBridge",
        "Azure Event Grid",
        "Azure Event Hubs",
        "Google Cloud Pub/Sub",
        "Confluent Cloud",
        "RabbitMQ",
        "Solace",
        "HiveMQ",
        "EMQX",
        "Mosquitto",
        "Custom"
      ],
      "description": "The broker or messaging platform hosting this source."
    },
    "protocol": {
      "type": "string",
      "enum": ["Kafka", "Pulsar Binary", "NATS", "AMQP 1.0", "AMQP 0-9-1", "MQTT 3.1.1", "MQTT 5.0", "STOMP", "HTTP", "WebSocket"],
      "description": "Wire protocol used to publish and consume from this source."
    },
    "transportEndpoint": {
      "type": "string",
      "format": "uri",
      "description": "Connection URL or bootstrap endpoint (e.g. kafka://broker:9092, mqtts://broker:8883, https://eventgrid.example/api/events)."
    },
    "topicOrChannel": {
      "type": "string",
      "description": "Broker-specific identifier — Kafka topic, Pulsar topic, NATS subject, MQTT topic filter, EventBridge bus name, Event Grid topic name, Pub/Sub topic ID."
    },
    "partitionCount": {
      "type": "integer",
      "minimum": 1,
      "description": "Partition count for log-based brokers (Kafka, Pulsar, Redpanda)."
    },
    "retention": {
      "type": "object",
      "description": "Retention policy for stored events.",
      "properties": {
        "duration": { "type": "string", "description": "ISO 8601 duration (e.g. P7D for seven days)." },
        "sizeBytes": { "type": "integer", "minimum": 0 },
        "compaction": { "type": "boolean", "description": "Whether log compaction is enabled (Kafka/Pulsar)." }
      }
    },
    "deliveryGuarantee": {
      "type": "string",
      "enum": ["at-most-once", "at-least-once", "exactly-once"],
      "description": "End-to-end delivery semantics this source offers consumers."
    },
    "orderingScope": {
      "type": "string",
      "enum": ["none", "partition", "key", "global"],
      "description": "Where order is preserved. 'partition' for Kafka, 'key' for Pub/Sub ordering keys, 'global' for Pulsar single-partition or NATS single-stream."
    },
    "cloudEventsSource": {
      "type": "string",
      "format": "uri-reference",
      "description": "Value this source will stamp into the CloudEvents 'source' attribute on emitted events. SHOULD be unique across the event catalog."
    },
    "cloudEventsTypes": {
      "type": "array",
      "description": "CloudEvents 'type' values produced by this source.",
      "items": {
        "type": "string"
      }
    },
    "schemaRegistry": {
      "type": "object",
      "description": "Schema registry binding for payloads emitted on this source.",
      "properties": {
        "vendor": {
          "type": "string",
          "enum": ["Confluent Schema Registry", "Apicurio Registry", "AWS Glue Schema Registry", "Azure Schema Registry", "Other", "None"]
        },
        "url": { "type": "string", "format": "uri" },
        "subject": { "type": "string", "description": "Registry subject name (often {topic}-value)." },
        "format": {
          "type": "string",
          "enum": ["JSON Schema", "Avro", "Protobuf", "XML Schema"]
        },
        "compatibility": {
          "type": "string",
          "enum": ["NONE", "BACKWARD", "BACKWARD_TRANSITIVE", "FORWARD", "FORWARD_TRANSITIVE", "FULL", "FULL_TRANSITIVE"]
        }
      }
    },
    "asyncApi": {
      "type": "string",
      "format": "uri",
      "description": "URL to an AsyncAPI document that documents this source."
    },
    "owner": {
      "type": "object",
      "description": "Team or service that owns the source.",
      "properties": {
        "team": { "type": "string" },
        "email": { "type": "string", "format": "email" }
      }
    },
    "tags": {
      "type": "array",
      "items": { "type": "string" }
    }
  },
  "additionalProperties": false
}

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