Zep

An open-source AI memory platform (Apache 2.0) built around the **Graphiti** temporal-knowledge-graph engine. Zep stores semantic facts as attributes directly on graph edges between entity nodes; every node and edge carries `valid_at` and `invalid_at` properties, letting agents traverse historical states, reason about knowledge decay, and maintain episodic memory autonomously. Repository: [github.com/getzep/graphiti](https://github.com/getzep/graphiti). Release cadence: **107 releases** as of 2026 — one of the most actively maintained AI memory engines.

Static text-as-memory loses the relational structure that gives memory its meaning. Zep transforms text into dynamic triplets (entity nodes + edges representing relationships between them) so that retrieving "what did Sarah work on in Q3 2025" returns not a paragraph but a traversable graph with explicit time-bound edges. This relational + temporal structure dramatically improves recall fidelity on multi-entity reasoning tasks where flat vector search degrades.

Temporal knowledge graphs for AI agents, multi-agent memory coordination, episodic memory with valid-time semantics, agent reasoning over evolving relationships, S3-backed graph persistence for memory durability.