Build stateful agents with memory that can learn and improve over time.

Letta (f.k.a. MemGPT) is actively developed. The current source code lives in letta-ai/letta-code, which includes the agent harness, interactive terminal UI, App Server, channels, and the runtime used by the desktop and web apps.

Install Letta from npm:

npm install -g @letta-ai/letta-code

Launch the interactive terminal UI:

letta

Run the App Server for local or self-hosted agents:

letta server

You can also use Letta through:

• the desktop app for macOS, Windows, and Linux
• chat.letta.com in your browser, including on mobile
• Slack, Telegram, Discord, and custom channels
• the Letta Agent SDK for building agents into TypeScript applications
• Letta Cloud for keeping agent memory, identity, and conversations available across computers

See the Letta documentation for current installation, development, and deployment instructions.

The archive branch contains the retired Letta V1 API server. Existing tags and releases remain available for reproducibility, but active projects should use the current source.