4 Best Open Source Alternatives to Mem0

1.Chroma

28.4kApache-2.0Rust

Chroma is open-source search infrastructure for AI that stores, indexes, and searches document collections by similarity. It is aimed at applications that need to add and query embeddings without wiring up separate tokenization and indexing components, making it a common building block for retrieval-augmented generation.

• In-memory client for quick prototyping
• Add, update, delete, get, and query collections
• Metadata filters and document text filters
• Automatic tokenization, embedding, and indexing

2.Letta

23.3kApache-2.0Python

Letta is a platform for building AI agents with advanced memory that can learn and self-improve over time. Formerly MemGPT, it is aimed at stateful agents that remember, learn continuously, and can be built into applications through an agents API.

• Stateful agents with advanced memory
• Local terminal agents through Letta Code
• Skills and subagents for agent workflows
• Pre-built memory and continual learning skills

3.Cognee

17.8kApache-2.0Python Self-host

Cognee is an open-source AI memory platform for AI agents. It gives agents persistent long-term memory across sessions by ingesting data and building a self-hosted knowledge graph, so agents can recall and use context beyond a single interaction.

• Persistent long-term memory for AI agents across sessions
• Ingests data and builds a self-hosted knowledge graph
• Combines vector embeddings, graph reasoning, and ontology generation
• Session memory with background sync to the graph

4.Zep

4.7kApache-2.0Python

Zep is an end-to-end context engineering platform for AI agents. It addresses the agent context problem by assembling relationship-aware context from chat history, business data, documents, and app events, then delivering the right information at the right time with sub-200ms latency.

• Ingests chat messages, business data, documents, and app events
• Graph RAG extracts relationships into a temporal knowledge graph
• Retrieves pre-formatted context blocks optimized for LLMs
• Tracks fact validity with valid_at and invalid_at dates