Living Memory Engine
A persistent world your agents share across sessions and models.
Living Memory Engine (LME) is a Model Context Protocol (MCP) memory server. It gives your agents — Claude Code, Cursor, ChatGPT, claude.ai, any MCP client — one shared place to remember, search, and hand work to each other. A fact told to one agent — or work left behind by one — can be picked up by a different agent, from a different vendor, tomorrow.
- Website: https://viibe.to/living-memory/
- Remote MCP endpoint:
https://lme.viibe.to/mcp(Streamable HTTP, OAuth 2.1 with dynamic client registration) - Free room: no signup —
POST https://lme.viibe.to/ons/newreturns a ready MCP URL - Local stdio server:
@nature-labs/lme-mcpon npm (open source, this repo) - Agent guide: SKILL.md · llms.txt
The mental model
A world is a place that persists — a project, not a person and not an agent. Agents are visitors: they arrive, leave something behind, and are replaced. Coordination happens by changing the shared place, not by agents addressing each other. Memory is what must persist and be searched; a handoff is what is in flight and expires. The human is the only participant who was present for all of it.
Connect
Remote — hosted world or free room
The hosted server speaks Streamable HTTP with OAuth 2.1 (dynamic client registration).
Claude Code:
claude mcp add --transport http living-memory https://lme.viibe.to/mcp
claude.ai / Claude Desktop: Settings → Connectors → Add custom connector → https://lme.viibe.to/mcp.
ChatGPT: Settings → enable Developer Mode, then add https://lme.viibe.to/mcp as a custom connector. Availability may depend on your ChatGPT plan.
It's 2026. MCP client support changes faster than READMEs do — ask your agent whether your client supports remote MCP today.
Free room, no signup — for trying the whole loop, or for clients without OAuth:
curl -X POST https://lme.viibe.to/ons/new
# → {"url": "https://lme.viibe.to/t/<token>/mcp", "expiresAt": "..."}
The returned URL is a private streamable-HTTP MCP endpoint (no auth header). The room stays available while it's used — any successful use keeps it alive; left inactive it is eventually forgotten, and its data is then deleted. A room differs from a world by how long it lasts, not by what it can do.
Local — stdio, open source
The npm package runs the memory surface as a local stdio server: one JSON file on your machine, can run fully offline.
claude mcp add living-memory -s user -- npx -y @nature-labs/lme-mcp
Any stdio MCP client: command npx, args ["-y", "@nature-labs/lme-mcp"]. Setup, embedding providers, environment, and failure modes: lme-mcp/README.md — written to be read by a coding agent, so hand it to yours.
The tools
The authenticated hosted world has all eleven tools. A free room has the memory surface, the handoff mailbox, and world_list. The local stdio server has the four memory tools.
Rooms and worlds
Handoff is not a paid feature: a room has it too, with a smaller mailbox (8 live notes) and notes that cannot outlive the room. The difference is lifetime, not capability.
Working with a world
The tools tell you what exists; this is how visitors are expected to behave:
- Arrive by reading. Call
memory_state/memory_searchbefore starting work — the world, not the conversation, is where the current position lives. - Durable goes to memory. A decision, fact, or correction that must survive you →
memory_add. - In-flight goes to handoff. Work you are passing to the next agent →
handoff_post. Handoff notes expire — never use them as permanent storage. - Leave the world resumable. Before you stop, write the state that lets the next visitor start from where you are, not from zero.
- Agents don't need to talk to each other. Change the shared world; the next agent reads the world.
How memory works
The engine underneath (engine/, @nature-labs/living-memory-engine) models memory as a mind, not a log:
- No context stuffing. The full history is never re-sent. Each recall retrieves the top-K most relevant memories by semantic similarity with diversity (MMR).
- Forgetting is a feature. Memories decay (Ebbinghaus-style), reinforce when used, and merge when duplicated, so an agent can run indefinitely on a small, bounded context instead of an ever-growing transcript.
- Deterministic evaluation.
engine/eval/run.tsdrives the real engine through four hypothesis scenarios against a naive resend-everything baseline — a measurement, not a test suite, and it reports the misses too (cd engine && npm run eval).
What's in this repo
The hosted remote server (lme.viibe.to) runs the same engine; its deployment lives outside this repo.
Status
Pre-alpha, evolving fast. The connect paths above are tested — the local package's verified agent/provider matrix is in lme-mcp/README.md. Product changes are logged, dated and verified, at What's new.
License
Apache-2.0.
Built as part of the Viibe World OS — a system that knows it is a system.
