Skip to main content
Glama

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.

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.

Related MCP server: mnemory

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

Tool

What it does

memory_add

Store a durable fact, decision, or correction

memory_search

Recall by meaning (MMR retrieval), not string match

memory_state

What is in memory right now — counts and recent facts

memory_forget

Remove a memory

handoff_post / handoff_read / handoff_list

A private 1–72 h message bus between your agents — raw notes passed verbatim, with sender and route stamped by the server

world_list

Which worlds this connection can reach

client_mint / client_list / client_revoke

Issue and withdraw revocable URL keys for agents that cannot sign in (hosted world, signed-in owner only)

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

Free room

World

Lifetime

Stays while used; forgotten after inactivity

Persists

Signup

None — mint a URL

OAuth sign-in, $9/month

Memory + handoff

Yes — full loop

Yes

Client keys (client_mint)

No

Yes — 90-day revocable leases

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_search before 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.ts drives 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

Dir

Role

lme-mcp/

The stdio MCP server published as @nature-labs/lme-mcp

engine/

@nature-labs/living-memory-engine — the framework-agnostic memory engine (decay / consolidation / crystallization / retrieval), pure ports & adapters

web/

The original browser lab: Vite + vanilla TS chat app where the engine was proven by เชียงใหม่ (Chiang Mai), a city-entity that senses real weather and remembers you across sessions — live at cm.viibe.to

mobile/

An earlier Expo prototype. Frozen

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.

Available Tools

4 tools
memory_addRemember a factAInspect

Store a durable fact, preference, decision, or correction so FUTURE sessions remember it. Call this whenever the user states something worth carrying forward — a preference, a project fact, a decision, a correction — without being asked. Memory persists across sessions and processes.

ParametersJSON Schema
NameRequiredDescriptionDefault
tagsNooptional tags
contentYesThe fact to remember, as a short natural-language statement
importanceNo0–10, default 7

TDQS

A3.6/5.0
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full behavioral disclosure burden. It does disclose the most important behavior: memory persists across sessions and processes. But it does not explain what happens if the same fact is added multiple times, whether overwrites/corrections replace existing memory, or what the tool returns or fails on.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is relatively tight and front-loaded with the core action. The list of example memory types is somewhat redundant with the phrase 'worth carrying forward,' but each sentence still contributes to deciding when and what to invoke.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple write/mutation tool with three parameters and no output schema, the description gives sufficient operational context: what to store, when to call, and the persistence guarantee. It lacks minor detail about edge cases or return behavior, but is likely adequate for an agent to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the schema already defines content, tags, and importance. The description adds mild guidance about what kind of content should be stored (preferences, corrections, decisions), but it does not add meaningful semantic detail beyond the schema's parameter descriptions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's action ('Store a durable fact, preference, decision, or correction') and its outcome ('FUTURE sessions remember it'). It is distinguishably an add/write operation compared to siblings like memory_search and memory_forget, though it never names these siblings explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides clear triggering context: 'Call this whenever the user states something worth carrying forward' and lists examples like preferences, facts, and corrections. However, it does not state when not to use the tool or explicitly point to alternative tools like memory_search or memory_forget.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

memory_forgetForget a memoryAInspect

DESTRUCTIVE. Deletes EVERY memory whose content contains the query as a case-insensitive substring — not semantic, not a single-item delete, and there is no undo. A short query deletes broadly. Use only when the user corrects a stored fact or explicitly asks you to forget something, and prefer a long distinctive phrase; check memory_state first if unsure.

ParametersJSON Schema
NameRequiredDescriptionDefault
queryYesText to match against memories to delete

TDQS

A4.9/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Since no annotations are provided, the description fully carries the behavioral transparency burden. It clearly discloses the destructive, irreversible nature of the operation, the case-insensitive substring matching behavior, and the broad-scope risk of short queries. This level of warning is critical for a destructive delete tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact and dense, front-loading the critical warning 'DESTRUCTIVE' before any other detail. Every sentence adds operational value, including when to use the tool, how to phrase the query, and what to check beforehand.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's destructive nature, the low parameter count, and the absence of an output schema, the description covers all essential aspects: action, matching semantics, irreversibility, risk, usage conditions, and a pre-check alternative. An agent is sufficiently prepared to avoid dangerous misuse.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema already documents the query parameter completely (100% coverage), but the description adds important semantic detail: the query is matched as a case-insensitive substring against memory content, not as a semantic match or single-item identifier. This extra context meaningfully improves the agent's understanding of the parameter.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action: deletes every memory whose content contains a case-insensitive substring, and explicitly distinguishes this from semantic or single-item delete. This differentiates the tool from siblings like memory_search and memory_add without ambiguity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit when-to-use guidance: only after user correction of a stored fact or explicit request to forget. It also warns of broad deletion risk, recommends using a long distinctive phrase, and suggests checking memory_state first when uncertain, giving the agent concrete decision-making guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

memory_stateMemory statusAInspect

Summarize what is currently in memory: counts plus the most recently stored facts. Reads the store directly — no embedding call, no network. Use to orient yourself at session start, or when the user asks what you remember. (selfFacets is always 0: this server does not run the engine's consolidation pass, so crystallization never happens.)

ParametersJSON Schema
NameRequiredDescriptionDefault

No parameters

TDQS

A4.5/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full transparency burden, and it does well: it discloses that the tool reads the store directly, requires no network or embedding, and notes the selfFacets-is-always-0 quirk with its root cause (no consolidation pass). This adds meaningful behavioral information an agent would not infer from the name or empty schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is this concise and well-structured: the main sentence states the function, the second sentence adds differentiating behavior (no embedding/network), the third gives usage guidance, and the parenthetical discloses a critical invariant. No word is wasted, and the most important information is front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only, zero-parameter tool with no output schema, the description is fully sufficient: it explains what the tool returns, when to call it, what side effects it does not have, and the only significant edge case. The agent has everything needed to invoke it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool accepts zero parameters, so the description does not need to explain parameter behavior. It instead clarifies what the output contains (counts and recent facts), which is the appropriate compensating information. The baseline of 4 for zero-parameter tools applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Summarize') and a precise resource ('what is currently in memory'), with output detail ('counts plus the most recently stored facts'). It also distinguishes itself from search-like siblings by noting it reads the store directly without embedding calls or network access, so an agent can tell this from memory_search at a glance.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit usage context: 'Use to orient yourself at session start, or when the user asks what you remember.' This is clear and actionable. However, it does not explicitly state when to prefer a sibling alternative such as memory_search for a specific fact lookup, so it stops one step short of full exclusion guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections.

  1. 4 tool updatesv0.1.1
    • First observedmemory_add
    • First observedmemory_forget
    • First observedmemory_search
    • First observedmemory_state

TDQS

A4.2/5.0

Scored across 4 tools

Disambiguation5/5

Each tool has a clearly distinct purpose: add, search, summarize, and delete. There is no meaningful overlap between retrieval (search) and store-state inspection (state), and forget is explicitly destructive and separate.

Naming Consistency4/5

All tools share a consistent memory_ prefix and lowercase style. memory_state is a noun where the others use action verbs, which is a minor deviation but does not create confusion.

Tool Count5/5

Four tools is a well-scoped, focused set for a memory engine. Each tool covers a core need without unnecessary surface area or duplication.

Completeness4/5

The toolset covers the essential lifecycle: store, retrieve, inspect state, and delete. A precise single-item delete or explicit memory update would round it out, but the destructive substring delete plus memory_add makes common workflows workable.

Maintenance

ActivityMaintained
ResponsivenessUnresponsive

Related MCP Connectors

Related MCP Servers

  • A
    license
    Not graded
    quality
    D
    maintenance
    MCP server providing managed persistent memory for AI agents. Read and write structured state across sessions, tools, and restarts at 1000+ requests per second, with no infrastructure to self-host or operate.
    2
    Apache 2.0
  • A
    license
    Not graded
    quality
    A
    maintenance
    Self-hosted MCP server giving AI agents persistent memory for personalization and context across conversations.
    277
    Apache 2.0
  • F
    license
    Not graded
    quality
    B
    maintenance
    Free, persistent memory layer for AI agents, enabling storage and semantic search of memories via MCP or REST.
    -