Letta

AI Memory

Letta (formerly MemGPT) provides a runtime where agents explicitly manage tiered memory through tool calls.

By AgDex Editorial · Reviewed July 2026

What is Letta?

Letta is an advanced agent runtime that introduces the concept of an operating system for LLMs. It manages context windows by moving data between "main memory" (context window) and "external storage" (databases) dynamically via tool calls.

Key Features

Tiered Memory: Core and archival memory systems.
Agent-Directed: The LLM decides when and what to read/write to memory.
State Management: Maintains perpetual conversation state.

Pricing Estimate (2026)

Open-Source. Managed services available via Letta Cloud with usage-based pricing.