{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://dynamicfeed.ai/schemas/attestation-v1.json",
  "title": "DF-VERIFY/1 — attestation/v1 profile (parametric trigger)",
  "description": "A signed, tamper-evident record that a parametric trigger ('metric op threshold' at a location) was MET or NOT MET against the live measurement at issued_at. Detached Ed25519 signature over the object minus its `signature`, json-sorted-compact. The dispute-proof oracle a parametric-insurance payout settles against.",
  "type": "object",
  "required": ["schema", "issuer", "issued_at", "trigger", "observed", "met", "signature"],
  "additionalProperties": true,
  "properties": {
    "schema": { "const": "attestation/v1" },
    "issuer": { "type": "string" },
    "issued_at": { "type": "string", "format": "date-time" },
    "trigger": {
      "type": "object",
      "required": ["metric", "op", "threshold"],
      "properties": {
        "metric": { "type": "string" },
        "op": { "enum": ["gt", "gte", "lt", "lte"] },
        "threshold": { "type": "number" },
        "location": { "type": "object" }
      },
      "additionalProperties": true
    },
    "observed": {
      "type": "object",
      "required": ["value", "source"],
      "properties": {
        "value": {},
        "unit": { "type": ["string", "null"] },
        "source": { "type": "string" },
        "measured_at": { "type": ["string", "null"] }
      },
      "additionalProperties": true
    },
    "met": { "type": "boolean" },
    "note": { "type": "string" },
    "signature": {
      "type": "object",
      "required": ["alg", "key_id", "canonicalization", "sig"],
      "properties": {
        "alg": { "const": "Ed25519" },
        "key_id": { "type": "string" },
        "canonicalization": { "const": "json-sorted-compact" },
        "sig": { "type": "string" },
        "ephemeral_key": { "type": "boolean" }
      },
      "additionalProperties": true
    }
  }
}