{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://spec.agentthreatrule.org/event/v1.0/schema.json",
  "title": "ATR Event v1.0",
  "description": "Machine-readable schema for ATR detection events. Normative spec at spec/atr-event-v1.0.md. License: CC BY 4.0.",
  "type": "object",
  "required": [
    "@timestamp",
    "atr.event_id",
    "atr.spec_version",
    "atr.engine_id",
    "atr.rule_id",
    "atr.rule_version",
    "atr.rule_status",
    "atr.severity",
    "atr.category",
    "atr.confidence",
    "atr.matched_field",
    "atr.matched_value_redacted",
    "atr.response_action",
    "agent.id",
    "agent.platform",
    "session.id",
    "service.name"
  ],
  "additionalProperties": true,
  "properties": {
    "@timestamp": {
      "type": "string",
      "format": "date-time",
      "description": "RFC 3339 UTC timestamp of when the rule fired."
    },
    "atr.event_id": {
      "type": "string",
      "pattern": "^[0-9a-f]{8}-[0-9a-f]{4}-7[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$",
      "description": "UUID v7 (time-ordered) globally unique event identifier per RFC 9562."
    },
    "atr.spec_version": {
      "type": "string",
      "pattern": "^\\d+\\.\\d+$",
      "description": "ATR spec version this event conforms to."
    },
    "atr.engine_id": {
      "type": "string",
      "pattern": "^[a-z0-9.-]+/[a-z0-9.-]+/[a-zA-Z0-9.+-]+$",
      "description": "Engine identifier in form <vendor>/<product>/<version>."
    },
    "atr.rule_id": {
      "type": "string",
      "pattern": "^ATR-(?:[A-Z]{2}-)?[0-9]{4}-[0-9]{5}$",
      "description": "Rule ID per ATR Rule Format Spec § 2. Canonical: ATR-YYYY-NNNNN. Sovereign-prefixed: ATR-XX-YYYY-NNNNN."
    },
    "atr.rule_version": {
      "type": "integer",
      "minimum": 1
    },
    "atr.rule_status": {
      "type": "string",
      "enum": ["draft", "experimental", "stable", "deprecated"]
    },
    "atr.rule_maturity": {
      "type": "string",
      "enum": ["draft", "experimental", "test", "stable", "deprecated"]
    },
    "atr.rule_review_status": {
      "type": "string",
      "enum": ["unreviewed", "community_reviewed", "tsc_approved"]
    },
    "atr.severity": {
      "type": "string",
      "enum": ["critical", "high", "medium", "low", "informational"]
    },
    "atr.category": {
      "type": "string",
      "description": "Top-level category from spec/category-registry/v1.0.yaml, OR 'unknown' for forward-compat with future registry versions."
    },
    "atr.subcategory": {
      "type": ["string", "null"]
    },
    "atr.confidence": {
      "type": "number",
      "minimum": 0.0,
      "maximum": 1.0
    },
    "atr.matched_field": {
      "type": "string",
      "enum": [
        "user_input",
        "agent_output",
        "tool_call",
        "tool_response",
        "skill_content",
        "mcp_exchange",
        "memory_write",
        "multi_agent_message"
      ]
    },
    "atr.matched_value_redacted": {
      "type": "string",
      "description": "Redacted match. Sensitive content (api keys, PII) replaced with [REDACTED:type:length]. forensic_mode deployments MAY emit unredacted."
    },
    "atr.response_action": {
      "type": "array",
      "items": {
        "type": "string",
        "enum": [
          "block_input",
          "block_output",
          "redact",
          "alert",
          "snapshot",
          "quarantine",
          "terminate_session"
        ]
      },
      "minItems": 0
    },
    "atr.response_taken": {
      "type": "array",
      "items": {
        "type": "string",
        "enum": [
          "block_input",
          "block_output",
          "redact",
          "alert",
          "snapshot",
          "quarantine",
          "terminate_session"
        ]
      }
    },
    "atr.response_threshold_met": {
      "type": "boolean"
    },
    "atr.sovereign_attestation": {
      "type": "object",
      "description": "Required when rule ID is sovereign-prefixed per CHARTER § 8.2.",
      "required": ["signer", "signature", "ca_chain"],
      "properties": {
        "signer": {"type": "string"},
        "signature": {"type": "string", "contentEncoding": "base64"},
        "ca_chain": {"type": "array", "items": {"type": "string"}}
      }
    },
    "agent.id": {
      "type": "string",
      "minLength": 1
    },
    "agent.platform": {
      "type": "string"
    },
    "agent.platform_version": {
      "type": ["string", "null"]
    },
    "agent.from_id": {
      "type": "string"
    },
    "agent.to_id": {
      "type": "string"
    },
    "agent.delegation_chain": {
      "type": "array",
      "items": {
        "type": "object",
        "required": ["agent_id", "capability_grant", "granted_by"],
        "properties": {
          "agent_id": {"type": "string"},
          "capability_grant": {"type": "string"},
          "granted_by": {"type": "string"}
        }
      }
    },
    "agent.identity_assertion": {
      "type": ["string", "null"],
      "description": "JWT-format identity assertion per IETF AI agent auth drafts (when finalized)."
    },
    "session.id": {
      "type": "string",
      "minLength": 1
    },
    "service.name": {
      "type": "string"
    },
    "service.version": {
      "type": "string"
    },
    "tool.name": {
      "type": "string"
    },
    "tool.args": {
      "type": "object",
      "description": "Redacted tool arguments."
    },
    "tool.privilege_class": {
      "type": "string"
    },
    "tool.target_jurisdiction": {
      "type": "string",
      "pattern": "^([A-Z]{2}|und)$",
      "description": "ISO 3166-1 alpha-2 country code or 'und' if unknown."
    },
    "memory.store_id": {
      "type": "string"
    },
    "memory.write_key": {
      "type": "string"
    },
    "memory.persistence_scope": {
      "type": "string",
      "enum": ["session", "user", "agent_global"]
    },
    "evidence.observation_id": {
      "type": "string",
      "pattern": "^[0-9a-f]{8}-[0-9a-f]{4}-[1-8][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$"
    },
    "evidence.signature": {
      "type": "string",
      "contentEncoding": "base64",
      "description": "Ed25519 signature over the canonical JSON encoding of this event."
    },
    "evidence.signature_key_id": {
      "type": "string"
    },
    "evidence.upstream_chain": {
      "type": ["array", "null"],
      "items": {
        "type": "string",
        "pattern": "^[0-9a-f]{8}-[0-9a-f]{4}-7[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$"
      }
    }
  }
}