Memory types
Engram models three memory types drawn from cognitive science. Each type has distinct retention characteristics, retrieval priority, and expected content shape. Pass the correct type to ensure the right memories surface at the right time.
Episodic
A timestamped record of something the agent did, saw, or decided. Episodic memories form the agent's lived history, ordered events that can be replayed or reasoned over.
When to use: Log task outcomes, user interactions, errors encountered, and any event where 'when' and 'what happened' matter.
Semantic
Durable facts, preferences, and world-knowledge the agent has accumulated. Unlike episodic memories, semantic memories are atemporal; they represent stable truths rather than events.
When to use: Store user preferences, configuration facts, known entities, and any knowledge the agent should treat as ground truth.
Procedural
Learned workflows, refined methods, and skill-like instructions the agent has figured out through experience. Procedural memory lets agents accumulate operational intelligence rather than rediscovering it each session.
When to use: Store step-by-step workflows, prompt templates that worked, and multi-step procedures refined over time.