An open-source memory server for date-based AI agent recall
Lians is an memory engine for AI agents. It is aimed at agents that handle time-sensitive data or regulated data. Each fact is stored with two time views: when the fact was true in the real world and when the system learned it.
This lets an agent recall only what was known as of a chosen past date. The full record is protected with an append-only hash chain, so hidden changes are easier to detect. Separate for each subject make deletion provable while keeping the intact.
Lians can run inside an app, on a , or in the cloud. It supports Python, , Go, Java, and C SDKs, native MCP support, local SQLite storage, and Postgres.
Key points
- Lians is an memory engine for AI agents.
- Agents can recall what was known on a specific past date.
- An append-only hash chain helps reveal hidden record changes.
- Per-subject make deletion provable while preserving an .
- It supports MCP, several language SDKs, local SQLite, Postgres, and cloud use.