65.8k stars · Apache-2.0 · 2.1.0 on PyPI as mem0ai, dated 18 September 2026. The newest GitHub tag is openclaw-v1.2.0 of the same date, which versions one of its plugins rather than the library — the monorepo-tag pattern recorded on 6 September 2026 · Track this in Scout
A memory layer that lets an AI application remember a user between separate conversations.
▶Repo detailsthe review · specs · pros & cons · install
What it is
A library, in Python and JavaScript, that extracts the facts worth keeping from a conversation, stores them in a search database, and retrieves the relevant ones when the next conversation starts. It works with several model providers and several storage backends, and there is a paid hosted version of the same thing.
What it is good for. Anyone building a product on top of a language model where the same person comes back. The alternative is sending the entire past conversation each time, which gets expensive and eventually exceeds what the model will accept. This sends a short, selected set of facts instead.
- It solves a problem almost every assistant-shaped product hits in its second month.
- Apache-2.0, and the self-hosted version is the same code as the paid one.
- Very actively developed: version 2.1.0 on PyPI dated 18 September 2026, code on 19 September 2026.
- Deciding what to remember costs a model call of its own, so the memory itself has a running bill.
- What it chooses to keep is a judgement made by a model, so it will sometimes store something useless and miss something important.
- The newest tag on GitHub is
openclaw-v1.2.0, which versions one of its plugins rather than the library. Use the PyPI version number, not the GitHub tag.
- topoteretes/cognee
It answers the same need by building a knowledge graph out of what it is given, which is more powerful and considerably more work to run.
Track this in Scout - letta-ai/letta
It also keeps agents stateful across sessions, as a whole framework rather than a memory layer; its README says the current source now lives in letta-ai/letta-code.
Track this in Scout - getzep/zep
It offers the same memory idea as a managed service, so this repository is mostly examples and integrations rather than the engine itself.
Track this in Scout
python3 -m venv venv source venv/bin/activate pip install mem0ai
