Mem0 and Zep both give AI agents long-term memory, but they take different shapes. Mem0 is an open-source memory layer: store facts, search them by meaning, keep it simple. Zep models memory as a temporal knowledge graph: entities and relationships that track how facts change over time. The right choice comes down to whether your questions are about facts or about relationships between facts. (Looking at the whole field? See our roundup of the best memory for AI agents.)
Mem0 vs Zep at a glance
| Mem0 | Zep | |
|---|---|---|
| Model | Memory layer (store/search facts) | Temporal knowledge graph |
| Shines at | Simple, fast fact memory | Relationships and change over time |
| Setup effort | Low | Higher (graph to reason about) |
| Documents / RAG | Not the focus | Not the focus |
When to choose Mem0
Choose Mem0 when you want a straightforward, open-source memory store bolted onto a custom agent, and your recall needs are "what did we decide" and "what does this user prefer" — not multi-hop relationship queries.
When to choose Zep
Choose Zep when your workload is genuinely about how entities relate and evolve — a graph earns its keep when questions span relationships over time, and it's overkill when they don't.
Where Kit for AI fits
If your agent also has to read your documents — specs, PDFs, scraped pages — neither is a document tool. Kit for AI pairs deduplicated remember/recall memory with document knowledge bases and hybrid retrieval behind one API and MCP server, so memory and RAG share one integration instead of two.
Related reading
Go deeper: our Mem0 alternative take · our Zep alternative take — or start with the complete guide to persistent memory for AI.
Want memory that reads your documents too, across every tool you use? Start free and connect over MCP or the REST API.