What is the best free alternative to Letta?
RAGFlow is the closest free alternative to Letta: same Agent Memory & RAG-as-a-Service sub-category, and it is free. Open-source RAG engine with deep document parsing and agent workflows
Best free Letta alternatives
Looking for a free alternative to Letta? Here are 9 agent memory & rag-as-a-service worth trying — 9 with a free tier. Letta itself is free tier + paid.
| Tool | Letta (you searched) | RAGFlow | MemOS | Mem0 |
|---|---|---|---|---|
| Pricing | freemium | free | free | freemium |
| Best for | Free BYOK plan supporting up to 3 stateful agents | Open-source RAG engine with deep document parsing and agent workflows | Memory operating system for LLM agents with hybrid retrieval and persistent memory | Free Hobby tier: unlimited end users, 10K add / 1K retrieval requests/month |
| Visit | Open ↗ | Open ↗ | Open ↗ | Open ↗ |
Letta alternatives — straight answers
Are there free Letta alternatives?
Yes — 9 of the 9 alternatives listed here are free or freemium: RAGFlow, MemOS, Mem0, Zep, Supermemory. None of them are paid-only.
Is Letta free?
Letta is free tier + paid. There is a free tier you can work in, with paid plans above it.
How were these Letta alternatives chosen?
They are the other tools in Agent Memory & RAG-as-a-Service, then the rest of AI Agents & Automation, ordered free tiers first and capped at 9. There is no sponsorship and no paid placement in that ordering — only the pricing tier decides.
All Letta alternatives
Browse Agent Memory & RAG-as-a-Service →✦ WhyA Letta alternative — Open-source RAG engine with deep document parsing and agent workflows.
- Open-source RAG engine with deep document parsing and agent workflows
- Grounded citations and template-based chunking
- Self-host with Docker; bring your own LLM
✦ WhyA Letta alternative — Memory operating system for LLM agents with hybrid retrieval and persistent memory.
- Memory operating system for LLM agents with hybrid retrieval and persistent memory
- Open source and self-hostable, with a cloud option
- Built for multi-agent and personal assistants
- Backed by MemTensor, a Shanghai team
Mem0
Agent Memory & RAG-as-a-Service
✦ WhyA Letta alternative — Free Hobby tier: unlimited end users, 10K add / 1K retrieval requests/month.
- Free Hobby tier: unlimited end users, 10K add / 1K retrieval requests/month
- Graph memory and entity linking for agent context
- Open-source core plus managed cloud API
Zep
Agent Memory & RAG-as-a-Service
✦ WhyA Letta alternative — Free plan: 10,000 monthly credits, 2 projects, 200ms retrieval.
- Free plan: 10,000 monthly credits, 2 projects, 200ms retrieval
- Graph RAG with automated context assembly from chat + business data
- Temporal knowledge graph for tracking how facts change over time
Supermemory
Agent Memory & RAG-as-a-Service
✦ WhyA Letta alternative — Free monthly usage allowance plus a Supermemory MCP server.
- Free monthly usage allowance plus a Supermemory MCP server
- Native connectors for Google Drive, Notion, OneDrive as memory sources
- Deduplication so repeated content isn't rebilled
✦ WhyA Letta alternative — LLM-agnostic memory layer that captures agent context as structured state.
- LLM-agnostic memory layer that captures agent context as structured state
- Works with LangChain, Pydantic AI, Agno and MCP clients such as Claude Code
- Open source under Apache 2.0, with free self-host
- Hosted cloud with an always-free development tier
✦ WhyA Letta alternative — Simple, fast graph-based RAG from HKU Data Science lab (EMNLP 2025).
- Simple, fast graph-based RAG from HKU Data Science lab (EMNLP 2025)
- Combines knowledge-graph and vector retrieval
- Works with local or hosted LLMs
✦ WhyA Letta alternative — Open-source memory platform that turns data into a knowledge graph plus vectors for agents.
- Open-source memory platform that turns data into a knowledge graph plus vectors for agents
- Python API with pluggable graph, vector and relational stores
- Self-host free; cloud option exists
✦ WhyA Letta alternative — Framework for building real-time temporal knowledge graphs for AI agents.
- Framework for building real-time temporal knowledge graphs for AI agents
- Powers Zep's memory layer; runs standalone
- Open source, works with Neo4j and other graph DBs