Highlights
About 40× smaller answers. Search returns a ranked list of names and the lines that matched, not every entity in full, so the agent can afford to check its memory before every task.
A web UI for people. See the whole graph grouped by type, follow relations, and add, edit or delete anything. Agent writes show up live.
Drop-in replacement. Same memory.jsonl file and the same nine tools as the
reference server. Switch in, and switch back whenever you like.
Works with every agent. Copy-paste setup for Claude Code, MiMo Code, Codex, Cursor, Copilot, Gemini CLI, Zed, JetBrains and more, plus the instructions that teach the agent to use it.
Stays small by itself. Short facts, a cap per entity, and an archive for the overflow, so the graph never grows into a wall of text.
Private and safe. Plain local files, daily backups, a write lock for parallel sessions, and no network access. One server file, zero dependencies.
The numbers
Measured on a real graph of 237 entities, 355 relations and 1,160 facts (tokens ≈ characters ÷ 4):
A narrow search that matches one or two entities saves less, because there is
little to trim. To measure your own graph, run node tools/bench.mjs from a clone;
it is read-only and prints sizes, never content.
Quick start
Claude Code: install the plugin. It adds the server, the instructions as a
skill, a short reminder at the start of each session, and /memory-ui.
/plugin marketplace add zamansheikh/memory-lean
/plugin install memory-lean@memory-lean
Any other agent: add the server to its MCP config, then give it the instructions.
{
"mcpServers": {
"memory": { "command": "npx", "args": ["-y", "memory-lean"] }
}
}
npx -y memory-lean --protocol >> AGENTS.md # into the rules file your agent reads
Just looking? Open the web UI on a made-up example graph:
npx -y memory-lean --ui --demo
The graph is created on the first write at ~/.claude/memory-graph/memory.jsonl,
whichever agent writes it, so all your agents share one memory. Set
MEMORY_FILE_PATH to keep it somewhere else.
Web UI
npx -y memory-lean --ui
This opens your memory in the browser. Everything an agent can do, you can do here:
- Explore. Each type gets its own bubble. Click an entity to highlight everything it connects to, drag nodes to arrange them, and scroll to zoom. Search matches names, types and facts.
- Edit. Add, edit and delete facts, rename an entity or change its type, add and remove relations, create and delete entities, and restore archived facts. Every change passes the same checks as the agents' tools.
- Watch. Changes your agents make appear within two seconds.
- Spot problems. The overview lists pending work, the most connected entities, and anything over budget, which is also marked on the graph.
The page runs on your machine only (127.0.0.1) and needs the one-time key in
the link it prints, so other websites cannot read or change your memory. Nothing
is uploaded anywhere.
How it works
Search, then open
The reference server answers a search with every matching entity in full, as pretty-printed JSON. memory-lean answers with a ranked list of names and the lines that matched:
> search_nodes { "query": "deploy" }
57 match "deploy", top 10 shown (narrow the query or raise limit). open_nodes for full entities.
- shop-backend [service] 12 obs, 6 rel
› 2026-03-02: deployed 2.4.0 to production
› deploy with scripts/release.sh, never by hand
- PENDING shop-backend 2.4.0 [pending] 2 obs, 3 rel
› …mobile apps still call the old endpoint until the deploy of 2.4.0 reaches them
The agent then opens only what it needs:
> open_nodes { "names": ["shop-backend"] }
## shop-backend [service] (3 archived)
- NestJS API behind api.example.com
- 2026-03-02: deployed 2.4.0 to production
## relations
shop-app -talks_to-> shop-backend
PENDING shop-backend 2.4.0 -blocks-> shop-app
Why it stays lean
How it keeps your data safe
Tools
The three read tools are marked read-only, so clients that support it can run them without asking.
Command line
With npx, put npx -y in front: npx -y memory-lean --ui.
Teach your agent to use it
A memory server only helps if the agent reads it before working and writes to it
when something changes. docs/AGENT-PROTOCOL.md is a
ready-made set of instructions: what to look up at the start of a task, what to
record, how to name things, and what never to store. The Claude Code plugin
includes it. For every other agent, one command installs it:
npx -y memory-lean --protocol >> AGENTS.md # into a rules file: always on
npx -y memory-lean --skill .agents/skills # as an Agent Skill: loaded when relevant
Adjust the entity types and names in it to your own work.
Coming from the reference memory server
Point MEMORY_FILE_PATH at your existing memory.jsonl and swap the command. The
file format is identical, so you can switch back at any time. Existing
observations longer than 300 characters are kept as they are; only new writes are
checked. To see what is over budget, and optionally fix it:
npx -y memory-lean --lint # report only
npx -y memory-lean --compact # back up, then move overflow to archive/
Settings
All optional, set as environment variables on the server:
FAQ
No. The server reads and writes local files and makes no network requests. The web UI listens on 127.0.0.1 only. Keep the graph out of git, and never store passwords, keys or tokens in it: record where a secret lives, not its value.
Yes. Every write takes a lock, re-reads the file and replaces it atomically, so parallel sessions (and the web UI) do not overwrite each other.
It needs no model, no index and no dependencies, and an agent's queries are mostly names it already knows. Good entity names matter more than clever queries.
When an entity passes 15 facts, the oldest dated ones move to archive/<entity>.md next to the graph. archived_observations, or the Archive section in the web UI, lists and restores them.
Roadmap
- Claude Code plugin with the server, a skill and
/memory-ui - Setup guides for 12 agents
-
rename_entityand archive restore - A web UI to explore and edit the graph
- Listed in the official MCP registry
- Listed in the Claude Code plugin directory
- Search across the archived facts of every entity
- Undo in the web UI
Contributing
Ideas, bug reports and pull requests are welcome. The server is one file with no
dependencies, the web UI is one HTML file, and npm test runs in a few seconds,
so a first change is quick to make. CONTRIBUTING.md has the
layout, the ground rules and a list of good first contributions.
If memory-lean saves you tokens, a ⭐ helps other people find it.
Support
memory-lean is free and MIT licensed. If it is useful to you, you can support the work:
Author
Created and maintained by Zaman Sheikh at Silifton.
Built on the file format and tool names of the Model Context Protocol reference memory server.
License
MIT © 2026 Zaman Sheikh. Free to use, change and share, including commercially; keep the copyright notice.