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SaveLatestStrategy

type SaveLatestStrategy = "message" | "invocation" | "trigger";

Defined in: src/session/session-manager.ts:43

Controls when snapshot_latest is saved automatically for agents.

There are two kinds of snapshots:

  • snapshot_latest: A single mutable snapshot that is overwritten on each save. Used to resume the most recent conversation state (e.g. after a crash or restart). Always reflects the last saved point in time.
  • Immutable snapshots: Append-only snapshots with unique IDs (UUID v7), created only when snapshotTrigger fires. Used for checkpointing — you can restore to any prior state, not just the latest.

SaveLatestStrategy controls how frequently snapshot_latest is updated:

  • 'invocation': after every agent invocation completes (default; balances durability and I/O)
  • 'message': after every message added (most durable, highest I/O)
  • 'trigger': only when a snapshotTrigger fires (or manually via saveSnapshot)

Under 'invocation' and 'message', guardrail redactions are persisted immediately so pre-redaction content never sits at rest. Under 'trigger', the caller’s snapshotTrigger stays in control; redactions are only flushed if the trigger fires or saveSnapshot is called.