Mem0, Zep, and Letta keep memory an application can retrieve. Archilas keeps dated notes, marks a newer decision as current, and gives that context to any MCP client. I do not claim Archilas beats them.
People ask me for a table with a winner. I do not have one. Those projects and this one do different jobs. Theirs is a store your code queries. Mine is the context I want already attached when Cursor, Claude Code, ChatGPT, Codex, or another MCP client starts.
The part I will stand behind
- A note has a date and a source.
- A later decision marks the earlier one. Both stay.
- If the note is missing, the result says so.
- The preprint’s failure counts are about my reader, not a ranking.
On one LoCoMo development split the preprint records 49 answer-stage failures where the gold evidence session was already in the prompt, and 22 retrieval-stage failures (14 ranked too low, 8 dropped by the context budget). That is a classification, not a leaderboard.