Skip to content
A

Letta

Memory & StateOpen source · Apache-2.0★ 25,025（2026-10-04）Self-hosted

Open-source framework for stateful agents, formerly MemGPT.

Letta is the open-source stateful-agent framework renamed from MemGPT in September 2024; MemGPT originated as a paper (arXiv:2310.08560) from the UC Berkeley Sky Computing Lab and Letta Inc. is led by its original authors.

Key facts

CategoryMemory & State
LicenseApache-2.0
LanguagePython
Self-hostedYes
GitHub stars25,025 (2026-10-04)
Last push2026-09-10
Last verified2026-10-04
Repositoryhttps://github.com/letta-ai/letta

Markdown version (for LLMs)

Tools in this category

Mem0

Open-source and hosted memory layer that gives agents persistent cross-session memory.

Open source★ 66,556

Qdrant

Rust vector search engine with HNSW and payload filtering, used for agent memory.

Open source★ 34,923

Cognee

AI memory combining knowledge graphs with vector storage.

Open source★ 31,345