Audit telemetry attributes against a contract, and against the thing a schema cannot se…

{
  "attribute_pointer": "/attributes",
  "cardinality_limit": 3,
  "contract": {
    "optional": [
      "region"
    ],
    "required": [
      "service",
      "environment"
    ],
    "types": {
      "environment": "string",
      "latency_ms": "number",
      "service": "string"
    }
  },
  "records": [
    {
      "attributes": {
        "environment": "prod",
        "latency_ms": 31.2,
        "region": "ap-southeast-2",
        "request_id": "r-1",
        "service": "checkout"
      },
      "name": "http.request"
    },
    {
      "attributes": {
        "environment": "prod",
        "latency_ms": 44,
        "region": "ap-southeast-2",
        "request_id": "r-2",
        "service": "checkout"
      },
      "name": "http.request"
    },
    {
      "attributes": {
        "environment": "prod",
        "latency_ms": "51",
        "request_id": "r-3",
        "service": "checkout"
      },
      "name": "http.request"
    },
    {
      "attributes": {
        "environment": "prod",
        "latency_ms": 28,
        "request_id": "r-4",
        "service": "checkout"
      },
      "name": "http.request"
    },
    {
      "name": "http.request"
    }
  ]
}

{
  "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."
  ],
  "attributes": [
    {
      "attribute": "environment",
      "declared": true,
      "distinct_count": 1,
      "presence_rate": 0.8,
      "records": 4,
      "types": {
        "string": 4
      }
    },
    {
      "attribute": "latency_ms",
      "declared": true,
      "distinct_count": 4,
      "presence_rate": 0.8,
      "records": 4,
      "types": {
        "integer": 2,
        "number": 1,
        "string": 1
      }
    },
    {
      "attribute": "request_id",
      "declared": false,
      "distinct_count": 4,
      "presence_rate": 0.8,
      "records": 4,
      "types": {
        "string": 4
      }
    }
  ],
  "cardinality_limit": 3,
  "complete": true,
  "conformant": false,
  "distinct_attribute_count": 5,
  "examined_record_count": 5,
  "finding_count": 9,
  "findings": [
    {
      "attribute": "request_id",
      "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
    }
  ],
  "findings_by_code": {
    "ATTRIBUTES_MISSING": 1,
    "ATTRIBUTE_CARDINALITY_RISK": 2,
    "ATTRIBUTE_TYPE_INCONSISTENT": 1,
    "ATTRIBUTE_TYPE_MISMATCH": 1,
    "UNDECLARED_ATTRIBUTE": 4
  },
  "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."
  ],
  "limits": {
    "cardinalityWarning": 100,
    "maxAttributes": 500,
    "maxEvents": 2000,
    "maxFindings": 500,
    "maxPartitions": 500,
    "maxSchemas": 100
  },
  "not_examined": [],
  "observed_at": "2026-10-02T00:00:00.000Z",
  "passed": false,
  "records_without_attributes": 1,
  "request_id": "example-request",
  "service_id": "telemetry_attribute_contract_audit",
  "service_version": "1.0.0",
  "supplied_record_count": 5
}