{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://raw.githubusercontent.com/api-evangelist/zipkin/refs/heads/main/json-schema/zipkin-api-v2-span-schema.json",
  "title": "Span",
  "description": "A Zipkin span represents an individual unit of work in a distributed trace.",
  "type": "object",
  "required": ["traceId", "id"],
  "properties": {
    "traceId": {
      "type": "string",
      "description": "Unique 128-bit or 64-bit trace identifier, hex encoded",
      "pattern": "^[0-9a-f]{16,32}$"
    },
    "parentId": {
      "type": "string",
      "description": "The parent span ID, hex encoded, absent if root span",
      "pattern": "^[0-9a-f]{16}$"
    },
    "id": {
      "type": "string",
      "description": "Unique 64-bit span identifier, hex encoded",
      "pattern": "^[0-9a-f]{16}$"
    },
    "kind": {
      "type": "string",
      "description": "The type of span",
      "enum": ["CLIENT", "SERVER", "PRODUCER", "CONSUMER"]
    },
    "name": {
      "type": "string",
      "description": "The logical operation this span represents"
    },
    "timestamp": {
      "type": "integer",
      "description": "Epoch microseconds of the start of this span"
    },
    "duration": {
      "type": "integer",
      "description": "Duration in microseconds of the critical path"
    },
    "localEndpoint": {
      "$ref": "zipkin-api-v2-endpoint-schema.json"
    },
    "remoteEndpoint": {
      "$ref": "zipkin-api-v2-endpoint-schema.json"
    },
    "annotations": {
      "type": "array",
      "description": "Events that explain latency with a timestamp",
      "items": {
        "$ref": "zipkin-api-v2-annotation-schema.json"
      }
    },
    "tags": {
      "type": "object",
      "description": "Key-value pairs providing additional context",
      "additionalProperties": {
        "type": "string"
      }
    },
    "debug": {
      "type": "boolean",
      "description": "True if this span was sampled with debug flag"
    },
    "shared": {
      "type": "boolean",
      "description": "True if this span ID is shared between client and server"
    }
  }
}