# Predicate Schema: stella.ops/federatedTelemetry@v1

## Overview

This predicate type represents a privacy-preserving telemetry bundle produced by a Stella Ops instance participating in federated exploit intelligence sharing. Each bundle contains differentially private aggregated CVE observation data.

## Predicate Type

```
stella.ops/federatedTelemetry@v1
```

## Schema

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "required": ["id", "siteId", "predicateType", "aggregatedAt", "totalFacts", "suppressedBuckets", "epsilonSpent", "buckets", "consentDigest", "createdAt"],
  "properties": {
    "id": {
      "type": "string",
      "format": "uuid",
      "description": "Unique bundle identifier"
    },
    "siteId": {
      "type": "string",
      "description": "Identifier of the originating federation site"
    },
    "predicateType": {
      "type": "string",
      "const": "stella.ops/federatedTelemetry@v1"
    },
    "aggregatedAt": {
      "type": "string",
      "format": "date-time",
      "description": "Timestamp of the aggregation cycle"
    },
    "totalFacts": {
      "type": "integer",
      "minimum": 0,
      "description": "Total number of telemetry facts processed"
    },
    "suppressedBuckets": {
      "type": "integer",
      "minimum": 0,
      "description": "Number of buckets suppressed by k-anonymity or budget exhaustion"
    },
    "epsilonSpent": {
      "type": "number",
      "minimum": 0,
      "description": "Total epsilon consumed in this aggregation"
    },
    "buckets": {
      "type": "array",
      "items": {
        "type": "object",
        "required": ["cveId", "noisyCount", "artifactCount"],
        "properties": {
          "cveId": {
            "type": "string",
            "description": "CVE identifier (e.g., CVE-2024-12345)"
          },
          "noisyCount": {
            "type": "number",
            "minimum": 0,
            "description": "Observation count with Laplacian noise applied"
          },
          "artifactCount": {
            "type": "integer",
            "minimum": 0,
            "description": "Number of distinct artifacts contributing to this bucket"
          }
        }
      },
      "description": "Non-suppressed aggregation buckets"
    },
    "consentDigest": {
      "type": "string",
      "description": "DSSE digest of the active consent proof at time of aggregation"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time",
      "description": "Timestamp when the bundle was created"
    }
  }
}
```

## Validation Rules

1. `id` must be a valid UUID v4.
2. `siteId` must be non-empty and match the originating site's configured identifier.
3. `epsilonSpent` must not exceed the site's total epsilon budget.
4. `consentDigest` must reference a valid, non-expired consent proof.
5. Each bucket's `artifactCount` must be >= the configured k-anonymity threshold.
6. `noisyCount` values are non-negative (noise-adjusted, may differ from true counts).

## Example Payload

```json
{
  "id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "siteId": "site-production-us-east",
  "predicateType": "stella.ops/federatedTelemetry@v1",
  "aggregatedAt": "2026-02-20T14:30:00Z",
  "totalFacts": 1547,
  "suppressedBuckets": 3,
  "epsilonSpent": 0.0833,
  "buckets": [
    {
      "cveId": "CVE-2024-21626",
      "noisyCount": 42.7,
      "artifactCount": 12
    },
    {
      "cveId": "CVE-2024-3094",
      "noisyCount": 8.2,
      "artifactCount": 6
    }
  ],
  "consentDigest": "sha256:abc123def456...",
  "createdAt": "2026-02-20T14:30:05Z"
}
```