Letta
Platform for stateful agents: AI with advanced memory that can learn and self-improve over time.
- Pricing
- Free plan
About Letta
Letta, known earlier as MemGPT, is a platform for developers building stateful AI agents that need to retain memory and improve across sessions rather than starting fresh each time. It is aimed at developers building agent applications in TypeScript as well as people who just want to chat with an agent.
A developer installs Letta from npm and launches an interactive terminal UI, or runs an App Server to host agents locally or self-hosted. Agents can also be used through a browser at chat.letta.com, through Slack, Telegram, Discord, and custom channels, or built into TypeScript applications with the Letta Agent SDK.
The current source code for Letta lives in a separate repository, letta-code, which includes the agent harness, interactive terminal UI, App Server, channels, and the runtime used by the desktop and web apps. Letta Cloud keeps an agent's memory, identity, and conversations available across different computers.
Letta is open source under the Apache-2.0 license, with more than 25.3k GitHub stars and 2.7k forks. Its retired V1 API server remains available on an archive branch for reproducibility, but active projects are directed to use the current source.
Use cases
- Chatting with a memory-persistent agent from a browser on mobile
- Building agents into a TypeScript application
Key features
- Advanced agent memory that learns and self-improves over time
- Interactive terminal UI for agents
- Self-hostable App Server for local agents
- Browser-based chat, including on mobile
- Multi-channel access via Slack, Telegram, and Discord
- SDK for building agents into TypeScript applications
- Cloud memory and identity persistence across devices
Pros and cons
Pros
Cons
Reviews
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