Sibyl Memory

Sibyl Memory is a long term memory plugin for AI coding agents. Most AI sessions forget everything when a chat ends, and Sibyl keeps the people, facts and decisions that should carry from one session to the next. It works with Claude Code, Cursor, Codex and Hermes Agent, installs with a single line, and runs locally so the user's data stays on their own machine. It stores memory in files and uses no vectors or embeddings. The vendor reports that it placed second on LongMemEval at 95.6 percent, a benchmark for long term AI memory, and describes itself as the only file based system in the top tier. The Pro plan adds self learning, so memory sharpens as it is used, and a memory linter that runs health checks on what the agent believes. Sibyl Labs, the maker, also lists a second product called Sibyl Sovereign, which is in development and places a deterministic, non AI rules gate between an agent and real world actions such as paying invoices or handling customer records. The plugin is aimed at developers and power users who work with coding agents across many sessions and devices. The Free plan costs $0, covers one user on one device with a storage limit, and needs no account. Pro costs $12 per month, or $9 per month billed annually, payable by card or USDC, and removes the storage limit and syncs one account across devices. A Fleet plan at $49 per month for shared memory across people and agents is marked as coming soon.