The top alternatives to Letta in the Memory Layer space, compared on features, pricing, and what they're best at.
Updated March 10, 2026
Letta is an innovative AI startup founded by Berkeley PhD students Sarah Wooders and Charles Packer, emerging from stealth in September 2024 with USD 10 million in seed funding led by Felicis. The company originated from the MemGPT research project at UC Berkeley's AI Research Lab and focuses on building stateful AI agents with advanced memory systems that can learn and self-improve over time. Letta's platform enables AI agents to maintain sophisticated memory structures—including entities, facts, and timelines—that can be queried and controlled, providing extreme interpretability with learned information stored as human-readable text.
Mem0 (formerly EmbedChain) is a memory layer for AI applications that gives LLMs and agents persistent, personalized memory. It automatically extracts, stores, and retrieves relevant memories from conversations, enabling AI systems to remember user preferences, past interactions, and context across sessions. Mem0 supports multiple storage backends and integrates with popular LLM frameworks.
Zep is a long-term memory service for AI assistants and agents. It stores conversation history, extracts facts and entities, builds temporal knowledge graphs, and enables semantic search across past interactions. Zep helps AI applications recall relevant context from previous conversations, making chatbots and agents feel more natural and personalized. Available as open-source and cloud-hosted.
LangMem is LangChain's long-term memory solution for AI agents. It provides tools for extracting, storing, and retrieving memories from agent interactions, enabling agents to learn and improve over time. LangMem integrates natively with the LangGraph agent framework and supports multiple memory types including semantic, episodic, and procedural memory.
Supermemory is an open-source Second Brain platform that helps users save, organize, and retrieve information using AI. Frequently trending on GitHub, it lets developers build personal knowledge assistants that remember bookmarks, notes, and web content. Popular with the personal AI builder community for creating AI-powered memory layers.
Cognee is an open-source memory management framework for AI applications that builds knowledge graphs from unstructured data. It extracts entities, relationships, and facts from conversations and documents, enabling AI agents to maintain structured long-term memory with semantic retrieval.
Graphiti is an open-source temporal knowledge graph engine built by the Zep team. It creates dynamic, time-aware knowledge graphs from conversational and unstructured data, enabling agents to maintain evolving memory with temporal reasoning. Graphiti powers many agent memory implementations and is often used alongside Zep for graph-based recall.
Automatic memory for AI agents - indexes connected data sources into a memory layer for personalized context.
One platform for routing, observability, tracing, and evals across every LLM provider.