hermes-agent vs Letta
Side-by-side comparison of two AI agent tools
h
hermes-agentopen-source
The agent that grows with you
Lettaopen-source
Letta is the platform for building stateful agents: AI with advanced memory that can learn and self-improve over time.
Metrics
| hermes-agent | Letta | |
|---|---|---|
| Stars | 250.3k | 25.0k |
| Star velocity /mo | 20.9k | 514.8128342245989 |
| Commits (90d) | 32.2k | 8 |
| Releases (6m) | 10 | 1 |
| Overall score | 0.9635171857739449 | 0.5221049967903727 |
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, hermes-agent or Letta?
- hermes-agent has more GitHub stars (250,306 vs 24,983).
- Which is more actively developed, hermes-agent or Letta?
- hermes-agent had more commits in the last 90 days (32,240 vs 8).
- Should I use hermes-agent or Letta?
- 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.