Letta vs R2R
A side-by-side comparison of two self-hosted self-hosted ai options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Letta | R2R |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 96 · Excellent | 52 · Fair |
| Category | Self-Hosted AI | Self-Hosted AI |
| License | Apache-2.0 | MIT |
| Language | Python | Python |
| Setup difficulty | Medium | Medium |
| Min. RAM | 2,048 MB | 4,096 MB |
| Deployment | docker, source | docker, source |
| GitHub stars | ★ 24,864 | ★ 8,004 |
| First released | 2023 | 2024 |
| Replaces | OpenAI Assistants | OpenAI Assistants |
What are Letta and R2R?
Letta
Letta, formerly known as MemGPT, is an open-source framework for building LLM agents with persistent memory and advanced reasoning. It provides a server, agent development kit, and visual interface for creating stateful assistants.
- Persistent agent memory
- Self-editing context
- Agent Development Kit
- Visual agent editor
R2R
R2R (RAG to Riches) is a retrieval-augmented generation engine that bundles ingestion, hybrid search, knowledge graphs, and agentic reasoning behind a single API. It is designed for self-hosted production deployment of document question answering.
- Hybrid and graph search
- Document ingestion pipeline
- Agentic RAG endpoints
- User and collection management
Letta vs R2R: key differences
Both projects are written in Python. Licensing differs — Apache-2.0 for Letta versus MIT for R2R. Letta is the lighter option, starting around 2,048 MB of RAM against 4,096 MB for R2R. Letta has the considerably larger community, at 24,864 GitHub stars versus 8,004.
Why pick each one
Choose Letta if…
- Persistent agent memory
- Visual agent builder
- Model-agnostic design
Watch out for
- Concept-heavy
- Best with capable models
Choose R2R if…
- Released under the MIT license
- First-class Docker support for quick deployment
- Mature project with 8k GitHub stars
- Written in Python
Frequently asked questions
Is Letta or R2R better?
Neither is universally better. Letta has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Letta and R2R free and open-source?
Yes. Letta is licensed under Apache-2.0 and R2R under MIT. Both can be self-hosted at no software cost.
Can I run Letta and R2R with Docker?
Letta: yes. R2R: yes.
Which is lighter on resources, Letta or R2R?
Letta has the smaller minimum footprint at 2,048 MB of RAM, compared to about 4,096 MB for R2R. Real-world usage depends on library size, user count, and enabled features.