Letta AI

AI agent framework with persistent memory and stateful LLM agent architecture

AI AgentsFreemium

Letta (formerly MemGPT) is an open-source AI agent development platform focused on building stateful agents with persistent, evolvable memory. It provides a framework for creating LLM agents that maintain long-term memory across conversations, update their persona and knowledge over time, and manage context intelligently through a tiered memory architecture. Researchers building agents for extended tasks, developers creating AI companions, and enterprise teams building persistent AI assistants use Letta to go beyond single-session LLM interactions and create agents with genuine conversational continuity.

Key Features

• ✓Persistent memory
• ✓Stateful agents
• ✓Memory tiers
• ✓Long-term context
• ✓Open-source