# Letta

> Open-source platform for stateful AI agents with persistent memory. Build, observe, and deploy agents via ADE, REST API, SDKs, and a desktop app. Connect tools via MCP; use any model; run self-hosted or on Letta Cloud.

Letta is a platform for building stateful AI agents with transparent, persistent memory (rooted in the MemGPT research). It ships a developer-first Agent Development Environment (ADE) for designing, observing, and editing agent state in real time, plus a REST API and Python/TypeScript SDKs to deploy agents as microservices. Agents are model-agnostic, support custom tools, and can connect to external tool libraries through Model Context Protocol (MCP). 

You can self-host from the open-source repo or use Letta Cloud to create, version, and operate agents at scale with templates, monitoring, and observability. A cross-platform Letta Desktop app is available for local development. The platform supports BYO LLM API keys, filesystem-backed knowledge, multi-agent patterns with shared memory, and portability via an agent file format.

## Features
- Persistent agent memory with transparent context management
- Agent Development Environment (ADE) for live inspect/edit of state, tools, and prompts
- Agents exposed as REST endpoints with auth/identities
- Python and TypeScript SDKs
- Model-agnostic: use OpenAI, Anthropic, Gemini, local (Ollama/vLLM)
- MCP integration for external tools and data sources
- Custom tools with sandboxed execution (cloud) and local tools (self-hosted)
- Agent templates, versioning, and rollbacks
- Monitoring and observability for production agents
- Self-hosting via Docker/pip or fully-managed Letta Cloud
- Desktop app for Mac/Windows/Linux (local agents)
- Filesystem and sources for document/knowledge ingestion
- Multi-agent systems with shared or linked memory
- Sleep-time/background workflows and request controls (tool rules)
- Portability between open source and cloud via agent file

## Integrations
OpenAI, Anthropic, Google Gemini, Ollama, vLLM, Model Context Protocol (MCP), LiveKit, Composio, Next.js, Vercel AI SDK

## Platforms
WEB, API, WINDOWS, MACOS, LINUX, DEVELOPER_SDK

## Pricing
Open Source, Free tier available

## Links
- Website: https://www.letta.com
- Documentation: https://docs.letta.com/
- Repository: https://github.com/letta-ai/letta
- EveryDev.ai: https://www.everydev.ai/tools/letta