agent
Open source
free (OSS) + managed cloud option
4.1/5
Letta (memory framework)
Agent memory framework that models memory like an operating system. Main context = RAM, archival storage = disk; the agent itself decides when to page. Originally MemGPT, now Letta. Model-agnostic (Anthropic, OpenAI, Ollama, Vertex), with REST API + dev environment for stateful agent services.
Overview
Agent memory framework that models memory like an operating system. Main context = RAM, archival storage = disk; the agent itself decides when to page. Originally MemGPT, now Letta. Model-agnostic (Anthropic, OpenAI, Ollama, Vertex), with REST API + dev environment for stateful agent services.
Pros
- OS-style memory architecture is uniquely suited to long-running agents
- Model-agnostic — pairs cleanly with local Ollama
- Mature dev environment (ADE) for inspecting agent state
- Open-source under Apache 2.0
Cons
- Steeper learning curve than drop-in Mem0 API
- Requires explicit memory-management tool calls in agent loop
- Less ergonomic for stateless one-shot agents
Compatibility
| Operating systems | macOS Linux Windows |
| GPU backends | n/a |
| License | Open source · free (OSS) + managed cloud option |
Get Letta (memory framework)
Frequently asked
Is Letta (memory framework) free?
Letta (memory framework) has a paid tier (free (OSS) + managed cloud option). Check the pricing page for current terms.
What operating systems does Letta (memory framework) support?
Letta (memory framework) supports macOS, Linux, Windows.
Which GPUs work with Letta (memory framework)?
Letta (memory framework) supports n/a. CPU-only inference is also possible but slow.
Reviewed by RunLocalAI Editorial. See our editorial policy for how we evaluate tools.