Summary
Memory tiering organizes agent state into three tiers with distinct persistence and access rules. Working memory holds current-turn context, session memory spans the active conversation, and long-term memory persists across sessions.
How it works
- Three tiers -- each tier has its own storage backend, retention policy, and access semantics.
- Read/write rules -- agents can only access tiers appropriate to the current operation.
- Promotion and eviction -- data moves between tiers based on usage patterns and importance scores.
Tiers
- Working memory: Current turn state, scratchpad, intermediate results. Volatile, cleared after each response.
- Session memory: Conversation history, user preferences for the session, task queue. Retained for the session duration.
- Long-term memory: User identity, learned facts, persistent preferences. Stored in durable storage across sessions.
Operations
- Read/write rules per tier: Tier 1 is read-write for the current turn only. Tier 2 is read-write for the session. Tier 3 is append-mostly with limited mutation.
- Promotion/demotion: Frequently accessed session facts may be promoted to long-term. Stale long-term facts may be demoted or archived.
- Eviction: Least recently used data is evicted first when tier capacity is reached. Eviction triggers a compaction or archival step.