Open-source alternatives to Letta

Letta (formerly MemGPT) is a framework for building stateful AI agents with self-editing memory — the agent manages its own context using an OS-inspired hierarchy of in-context and archival memory. The core framework is open source, but Letta also runs a managed cloud platform for hosting and monitoring agents, which is the paid, closed part of the offering.

Mem0 and Supermemory take a different architectural approach — an external memory layer your application calls into, rather than memory the agent edits itself — which is worth comparing if Letta's self-editing model isn't the fit you need.

FAQ

Is there a free, open-source alternative to Letta?

Letta's core framework is itself already open source. Mem0 (Apache-2.0) and Supermemory (MIT) are open-source alternatives if you want an external memory layer instead of Letta's self-editing agent memory model.

What's the best open-source alternative to Letta?

Mem0 is the better pick for a general-purpose external memory layer with multi-signal retrieval. Supermemory is the better pick if low-latency retrieval and graph-based memory structure are the priority.

What are the top open-source alternatives to Letta?

Browse all open-source alternatives to Letta above, or explore the full Vector Database category for more options.