Event Schema
The Layer-7 event schema defines the immutable event structures written to the Decision Ledger. Events are append-only and represent state transitions, approvals, risk evaluations, and execution confirmations.
Events are the atomic units of governance. If it is not an event, it is not auditable.
Base Event Structure
{
“event_id”: “uuid”,
“schema_version”: “1.0.0”,
“decision_id”: “uuid”,
“event_type”: “string”,
“timestamp”: “ISO-8601”,
“actor_id”: “uuid”,
“integrity_hash”: “sha256”,
“previous_hash”: “sha256”
}
Each event references the previous event hash to maintain ledger continuity.
Canonical Event Types
| Event Type | Description |
|---|---|
| decision.requested | Initial submission of decision intent. |
| risk.evaluated | Risk scoring result recorded. |
| authority.approved | Approval granted by authorized role. |
| authority.rejected | Decision rejected by authority. |
| execution.confirmed | Execution verified by gateway. |
| override.breakglass | Emergency override event. |
Risk Evaluation Event
{
“event_type”: “risk.evaluated”,
“risk_score”: 0.87,
“risk_band”: “high”,
“policy_version”: “1.2.0”,
“threshold_triggered”: true
}
Authority Approval Event
{
“event_type”: “authority.approved”,
“role”: “executive”,
“actor_id”: “uuid”,
“approval_scope”: “full”,
“expires_at”: “ISO-8601”
}
Ledger Integrity Model
- Append-only writes
- Hash chaining
- Periodic integrity verification
- External export capability
Ledger tampering invalidates the integrity chain and forces system restriction mode.
Audit Export Structure
{
“decision_id”: “uuid”,
“schema_version”: “1.0.0”,
“event_chain”: [ … ],
“chain_integrity_verified”: true,
“export_timestamp”: “ISO-8601”
}
Audit exports must include full event chains and integrity verification status.