EngineEvent

One event in the monotonic semantic event stream of a turn.

Events are the durable, replayable record a DurabilityPort persists. Run identity links delegated (nested) engine runs to their parent for cross-run observability.

Class Diagram

---
title: EngineEvent
config:
  look: handDrawn
  theme: colorful
  class:
    hideEmptyMembersBox: true
---
classDiagram
    class EngineEvent {
        +int64 sequence
        +string id
        +string timestamp
        +string sessionId
        +string turnId
        +string runId
        +string parentRunId
        +int32 delegationDepth
        +string invocationId
        +int32 iteration
        +string kind
        +unknown payload
    }

Yaml Example

id: evt_abc123
timestamp: 2025-01-01T00:00:00Z
sessionId: sess_abc123
turnId: turn_abc123
runId: run_abc123

Properties

Name	Type	Description
sequence	int64	Monotonic sequence number within the run, starting at one
id	string	Stable unique identifier for this event
timestamp	string	RFC 3339 timestamp when the event was emitted
sessionId	string	Stable session identifier
turnId	string	Stable turn identifier
runId	string	Stable identifier of this engine run
parentRunId	string	Run identifier of the parent run when this run was delegated
delegationDepth	int32	Zero-based delegation nesting depth; 0 for a top-level run
invocationId	string	Model invocation identifier, when the event belongs to an invocation
iteration	int32	Zero-based model loop iteration, when applicable
kind	string	Semantic kind of this event
payload	unknown	Opaque event-specific payload