# Letta

Letta is a framework and cloud platform for building AI agents that remember. Born from the MemGPT research project, it gives agents a structured memory system that manages what stays in the model's limited context versus what is stored externally, so agents can retain facts, preferences, and history across long conversations and sessions instead of forgetting everything between calls. Developers define agents with tools, memory blocks, and personas, then run them through an SDK and API, with a visual Agent Development Environment for inspecting and editing an agent's memory and reasoning step by step. Letta is model-agnostic, works with major LLM providers, and supports persistent, multi-agent systems that can be deployed as services. It targets developers and teams building assistants, copilots, and autonomous agents that need durable memory and transparent, debuggable state rather than stateless one-off prompts.

## Quick facts

- Categories: LLM, Developer Tools, AI Agents, Automation
- Pricing: Freemium (free plan + paid tiers)
- Free plan: Yes
- Official site: https://www.letta.com
- Last checked: 2026-11-02

## Links

- Nextool.ai page: https://nextool.ai/tools/letta/
- Alternatives: https://nextool.ai/alternatives/letta/

Source: Nextool.ai (https://nextool.ai/tools/letta/). Pricing and features change; confirm on the provider's site before relying on them.