Mem0 vs Letta
Mem0 is a memory layer you plug into your existing agent. Letta (formerly MemGPT) is a complete agent framework with memory management built in. A focused API vs a full runtime.
Memory add-on vs agent-with-memory. Different philosophies, different trade-offs.
The Key Difference
Memory layer (add-on)
A managed memory API that plugs into any agent. Cloud-first with an optional local mode via OpenMemory. Doesn't manage agents — just stores and retrieves memories for them.
Agent runtime with memory
A complete agent framework where memory management is a core feature, not a separate service. Agents manage their own archival and core memory blocks. Requires adopting the full Letta runtime.
Full Comparison
Every row verified from public documentation and GitHub repos. Updated April 2026.
Consider OMEGA If…
Mem0 requires a cloud account or OpenAI key. Letta requires adopting an entire agent framework. If you want a standalone memory layer that works locally with any MCP client, OMEGA fills that gap.
LongMemEval
95.4%
Neither Mem0 nor Letta have published scores
MCP tools
25
vs 9/4 (Mem0), 7 (Letta community)
Dependencies
Zero
No cloud, no PostgreSQL, no API keys
Scope
Memory only
Works with any agent, no framework lock-in
Frequently Asked
Should I choose Mem0 or Letta for my project?
Choose Mem0 if you already have an agent and just need a memory layer to plug in via API. Choose Letta if you want a complete agent framework with memory management built in. They solve different scopes of the problem.
Is Letta still called MemGPT?
Letta was originally released as MemGPT, a research project on memory management for LLMs. It has since evolved into a full agent framework and rebranded to Letta. The underlying memory architecture (archival + core memory) remains, but the project scope is now much broader.
Can I use Mem0's memory with Letta's agent framework?
Not directly. Mem0 and Letta have different APIs and memory models. You would need custom integration code. Both offer MCP tools, so an MCP-compatible agent could theoretically use either, but they are designed as separate systems.
Is there a memory-only system that works without a framework or cloud API?
OMEGA is a standalone memory layer that works with any MCP-compatible agent. No framework lock-in, no cloud dependency. It runs locally with SQLite and ONNX embeddings, scores 95.4% on LongMemEval, and provides 25 MCP tools.