Letta vs MemOS
Side-by-side comparison of two AI agent tools
Lettaopen-source
Letta is the platform for building stateful agents: AI with advanced memory that can learn and self-improve over time.
M
MemOSopen-source
Self-evolving memory OS for LLM & AI Agents: ultra-persistent memory, hybrid-retrieval, and cross-task skill reuse, with 35.24% token savings and DeepSeek Harne
Metrics
| Letta | MemOS | |
|---|---|---|
| Stars | 25.0k | 11.7k |
| Star velocity /mo | 514.8128342245989 | 971.6666666666666 |
| Commits (90d) | 8 | 264 |
| Releases (6m) | 1 | 10 |
| Overall score | 0.5221049967903727 | 0.730926100634913 |
Pros
- +Advanced persistent memory system that allows agents to learn and improve over time across sessions
- +Dual deployment options with both local CLI tool and cloud API for different use cases and security requirements
- +Model-agnostic architecture supporting multiple LLM providers with extensive SDK support for TypeScript and Python
Cons
- -Requires Node.js 18+ for CLI usage, which may limit adoption in some environments
- -API-based functionality requires API keys and cloud dependency for full feature access
- -As a relatively new platform for stateful agents, may have a learning curve for developers new to persistent memory concepts
Use Cases
- •Building coding assistants that remember project context and learn from previous debugging sessions
- •Creating customer support agents that maintain conversation history and learn customer preferences over time
- •Developing personal AI assistants that evolve their responses based on user behavior patterns and feedback
FAQ
- Which is more popular, Letta or MemOS?
- Letta has more GitHub stars (24,983 vs 11,660).
- Which is more actively developed, Letta or MemOS?
- MemOS had more commits in the last 90 days (264 vs 8).
- Should I use Letta or MemOS?
- Compare their capabilities, limitations and "best for" notes above. Both are open source, so trying each on a small task is the fastest way to decide.