Letta
Letta
Platform for stateful agents with persistent memory (formerly MemGPT), with an agent harness, server and SDK.
Install
Run in your terminal
pip install letta-client
Run in your terminal
npm install @letta-ai/letta-agent-sdk
Run in your terminal
npm install @letta-ai/letta-code
Latest version read from npm package @letta-ai/letta-agent-sdk.
Multi-agent patterns
Handoffs
One agent passes the conversation to another agent, which takes over.
Not shown in the docs.
Subagents / agents as tools
A main agent calls other agents like tools and gets their result back, each with its own context.
How Letta does itGraph or workflow
You define steps and edges (or a workflow), and the framework runs agents and functions through them.
Not shown in the docs.
Group chat / crew
Several agents with roles work together on a task, coordinated by a manager or a selection rule.
Not shown in the docs.
Human in the loop
The run pauses for a person to approve, edit or answer before it continues.
How Letta does itProtocols and hosting
Questions
Does Letta support MCP?
Yes. Letta's documentation shows agents using tools from MCP servers.
Does Letta support the A2A protocol?
Its documentation does not cover A2A as of 2026-10-07.
What multi-agent patterns does Letta support?
The docs show: subagents / agents as tools, human in the loop.
Links
Alternatives in the same languages
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Reviewed Oct 7, 2026.