Zep

Description

Zep is a context engineering platform built around Graphiti, an open-source temporal knowledge graph engine that ingests conversational messages and structured business data and turns them into a graph of entities and facts with bi-temporal validity windows. Each user has their own User Graph; threads under that user feed messages into the graph via `thread.add_messages`, and agents retrieve assembled context with `thread.get_user_context` or low-level `graph.search`. When new data contradicts a prior fact, Zep stores the invalidation time on the fact's edge rather than deleting it, so agents can reason about how preferences and relationships changed. SDKs are available in Python, TypeScript, and Go.

Solution

Sidecar memory service backed by a temporal knowledge graph. The application creates a User and a Thread; on each user turn it calls `thread.add_messages` which ingests messages into that user's graph, where Graphiti extracts entities and facts as edges with valid_at and invalid_at timestamps. Before generating a reply the agent calls `thread.get_user_context` (high-level) or `graph.search` (low-level) to retrieve assembled context. Fact invalidation is handled automatically: when new data contradicts an existing fact, Zep stamps the old edge as invalidated rather than deleting it.

Primary use cases

• long-term agent memory with temporal reasoning
• voice and video agents needing sub-200ms context retrieval
• personalized assistants that track changing user state
• Graph RAG over conversational and business data