telemetry attribute contract audit derived

{
  "input": {
    "body": {
      "records": [
        {
          "name": "http.request",
          "attributes": {
            "region": "ap-southeast-2",
            "service": "checkout",
            "latency_ms": 31.2,
            "request_id": "r-1",
            "environment": "prod"
          }
        },
        {
          "name": "http.request",
          "attributes": {
            "region": "ap-southeast-2",
            "service": "checkout",
            "latency_ms": 44,
            "request_id": "r-2",
            "environment": "prod"
          }
        },
        {
          "name": "http.request",
          "attributes": {
            "service": "checkout",
            "latency_ms": "51",
            "request_id": "r-3",
            "environment": "prod"
          }
        },
        {
          "name": "http.request",
          "attributes": {
            "service": "checkout",
            "latency_ms": 28,
            "request_id": "r-4",
            "environment": "prod"
          }
        },
        {
          "name": "http.request"
        }
      ],
      "contract": {
        "types": {
          "service": "string",
          "latency_ms": "number",
          "environment": "string"
        },
        "optional": [
          "region"
        ],
        "required": [
          "service",
          "environment"
        ]
      },
      "attribute_pointer": "/attributes",
      "cardinality_limit": 3
    },
    "type": "http",
    "method": "POST",
    "bodyType": "json"
  },
  "output": {
    "type": "json",
    "example": {
      "limits": {
        "maxEvents": 2000,
        "maxSchemas": 100,
        "maxFindings": 500,
        "maxAttributes": 500,
        "maxPartitions": 500,
        "cardinalityWarning": 100
      },
      "passed": false,
      "complete": true,
      "findings": [
        {
          "code": "UNDECLARED_ATTRIBUTE",
          "detail": "Record 0 carries request_id, which the contract does not declare.",
          "record": 0,
          "attribute": "request_id"
        },
        {
          "code": "UNDECLARED_ATTRIBUTE",
          "detail": "Record 1 carries request_id, which the contract does not declare.",
          "record": 1,
          "attribute": "request_id"
        },
        {
          "code": "UNDECLARED_ATTRIBUTE",
          "detail": "Record 2 carries request_id, which the contract does not declare.",
          "record": 2,
          "attribute": "request_id"
        }
      ],
      "attributes": [
        {
          "types": {
            "string": 4
          },
          "records": 4,
          "declared": true,
          "attribute": "environment",
          "presence_rate": 0.8,
          "distinct_count": 1
        },
        {
          "types": {
            "number": 1,
            "string": 1,
            "integer": 2
          },
          "records": 4,
          "declared": true,
          "attribute": "latency_ms",
          "presence_rate": 0.8,
          "distinct_count": 4
        },
        {
          "types": {
            "string": 4
          },
          "records": 4,
          "declared": false,
          "attribute": "request_id",
          "presence_rate": 0.8,
          "distinct_count": 4
        }
      ],
      "conformant": false,
      "request_id": "example-request",
      "service_id": "telemetry_attribute_contract_audit",
      "assumptions": [
        "Cardinality is counted within the batch supplied, and each distinct value of an attribute is one series in a metrics backend, which is why it is reported as a risk.",
        "An attribute that appears as two types across a batch cannot be indexed by a typed backend, whatever any single record looks like."
      ],
      "limitations": [
        "Attribute shape and cardinality over the batch supplied. Whether the batch represents real traffic is not knowable here, so a cardinality figure is a lower bound.",
        "conformant is true only when every record was examined, every required attribute was present, and no type or cardinality problem was found."
      ],
      "observed_at": "2026-10-02T00:00:00.000Z",
      "not_examined": [],
      "finding_count": 9,
      "service_version": "1.0.0",
      "findings_by_code": {
        "ATTRIBUTES_MISSING": 1,
        "UNDECLARED_ATTRIBUTE": 4,
        "ATTRIBUTE_TYPE_MISMATCH": 1,
        "ATTRIBUTE_CARDINALITY_RISK": 2,
        "ATTRIBUTE_TYPE_INCONSISTENT": 1
      },
      "cardinality_limit": 3,
      "examined_record_count": 5,
      "supplied_record_count": 5,
      "distinct_attribute_count": 5,
      "records_without_attributes": 1
    }
  }
}