Letta vs Zep
A side-by-side comparison of Letta and Zep, two Memory tools, drawn from Ignaite's continuously-verified listings.
Compared from listings verified as of
At a glance
The honest brief
Letta
The productized MemGPT successor — agents edit their own memory blocks (memory-as-OS) to manage a finite context window.
- Self-editing agent memory
- Open source, model-agnostic
- REST APIs + multi-language SDKs
- Reference architecture for memory
- Developer-focused, not no-code
- Memory model has a learning curve
- Younger, evolving framework
Zep
Stores a temporal knowledge graph (via OSS Graphiti) that versions how facts change over time, not flat snapshots.
- Open-source Graphiti engine (Apache-2.0)
- Managed Zep Cloud option
- Pulls in chat + business data
- Long-term context for agents
- Graph approach has learning curve
- Cloud is credit-based pricing
- Heavier than simple vector memory
- Newer ecosystem