Memory & PersistenceOpen Source✦ Free Tier

Letta

Stateful agents with long-term memory — formerly MemGPT

13,200 stars● Health 100/100 — Active· commit recency (40 pts) · star momentum (30 pts) · issue ratio (20 pts) · forks (10 pts)App Infrastructure

About

Letta (formerly MemGPT) is an open-source framework for building stateful AI agents with persistent, editable memory. Agents remember conversations across sessions, search their own memory, and update their knowledge over time — solving context window limitations.

Choose Letta when…

  • need agents with persistent cross-session memory
  • context window length is limiting your application
  • building personal assistants or long-running agents

Builder Slot

How does your AI remember?Optional for most stacks

Persistent memory layers that give AI agents long-term recall of users, sessions, and context across conversations

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AIchitect's Genome scanner detects Letta in your project via these signals:

pip packages
letta
env vars
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config files
.letta/

Integrates with (1)

OpenAI APILLM Infrastructure

Letta agents use OpenAI models as their reasoning core, extended with Letta's persistent memory layer.

Long-running stateful agents that remember context across sessions without context window limits.

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Alternatives to consider (1)

Pricing

✦ Free tier available
Open SourceFree
Cloud$20/mo

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Ruled out by 1 stack

Memory-Augmented Agent Stack
Pick instead of Mem0 when the agent must reason about its own memory as state, not just retrieve facts

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