open-memex

open-memex

Persistent memory for your AI coding agents — on your machine, in plain Markdown, shared by every tool you code with.

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Every AI coding session starts from zero: you re-explain the project, the agent rediscovers the same gotchas, and yesterday's decisions vanish when the chat ends. open-memex gives your agents a memory that survives the session. Say "remember: we deploy on Fridays" once, and next week Copilot, Cursor, opencode, or Claude Code already knows — because they all read and write the same local memory on your machine.

• Free and open source (Apache-2.0). No account, no cloud, no telemetry — everything lives on your machine, in files you can open and edit.
• Local-first: memories are plain Markdown files (the source of truth) with a rebuildable SQLite keyword index. Nothing leaves your machine unless you explicitly share it.
• One memory, every agent: wire up several editors with one command; they share the same memory instead of keeping separate silos.
• Precise synonym search: ship finds deploy, 单点登录 finds SSO — a curated multilingual map of equivalents is indexed with every memory at write time, so no related wording misses the right answer. Deterministic and auditable, no embedding model required.
• A map, not just search: a derived knowledge graph connects your project memories — supersedes chains, shared tags, explicit mentions — and injects a compiled outline at session start, so the agent sees what's in memory without searching. Structural edges only, no LLM.

New here? This README takes you from install to a working memory in about a minute. The concept guide explains the mental model in depth once you're up and running.

Contents

• Quick start
• Core concepts
• Which editors, which features
• How it compares
• Installation
• Setting up your editor
• What init changes on your machine
• Capture: how memories get saved
• Tools the agent gets
• Memory types
• Team workflow: sharing memories through Git
• Retrieval: how memories come back
• Security & data
• Limitations
• Upgrading
• Storage layout
• Config
• CLI reference
• Session working state
• Knowledge graph
• MCP server
• Scopes, in detail
• Troubleshooting
• FAQ
• Project status

Quick start

You need Node.js ≥ 22.14 (check with node -v). Then:

npm install -g open-memex

open-memex init

init detects the editors you have installed (VS Code, Cursor, opencode, and Visual Studio when your project has a solution file) and connects each one to open-memex. Restart your editor afterwards.

See it work (30 seconds):

open-memex add "This project deploys on Fridays"

Now open a new chat in your editor and ask your agent: *"When does this project deploy?"* It already knows — no re-explaining. That round trip, capture once and recall forever, is the whole product. Everything below is detail.

Optional but recommended — check everything is wired up:

open-memex doctor

Core concepts

Four ideas explain almost everything open-memex does.

1. Two scopes: `project` and `personal`. Every memory belongs to one of two places:

• project — knowledge about one codebase (decisions, constraints, lessons). Scoped to the current repo automatically; you never set this up by hand.
• personal — knowledge about *you* (preferences, habits) that applies in every project. It lives only on this machine and can never be shared into a repo.

Facts about you ("I prefer concise diffs") go to personal; everything else defaults to the current project.

2. Capture → recall. Memories are saved as small Markdown files, one fact each. On the first turn of every new session, open-memex hands your agent the most relevant ones automatically, so it starts the session already knowing them. The agent can also search the full memory on demand. You never have to "load" anything yourself.

3. Your files, your rules. The Markdown files are the source of truth — open them, edit them, delete them, grep them. The SQLite index next to them is just a search accelerator and rebuilds from the files at any time (open-memex reindex). Team sharing, when you want it, goes through the same review flow as code: nothing is shared automatically (see Team workflow).

4. Knowledge stays current. Facts change: decisions get reversed, tools get replaced, yesterday's gotcha gets fixed. open-memex doesn't let the old version quietly linger — memory_supersede replaces a memory with its newer version and keeps the chain, so retrieval serves the current fact while the history stays auditable. Merely stale memories can be deprecated, and open-memex audit reports duplicates, stale entries, and broken chains. Pruning is a feature, not housekeeping: shared memory rots without it.

Which editors, which features

open-memex talks to editors two ways: a native opencode plugin, and a standard MCP server that any MCP-capable editor can use. (MCP — Model Context Protocol — is the open standard editors use to give agents extra tools; open-memex appears in your editor as a set of memory_* tools.) What you get depends on which path an editor uses:

\* MCP has no hard session-start hook, so open-memex sends the agent guidance in the MCP handshake (including how many drafts are waiting) and init writes the fuller version into the editor's instruction files. In practice agents follow it; the opencode plugin is the only path with true built-in first-turn injection. The Tools section lists the 6 core tools and the 6 extra workflow tools, so the "6 vs 12" split is explicit.

All editors on the same machine read and write the same memory — a constraint captured in VS Code is respected in opencode; a lesson learned in Cursor shows up in Claude Code. (Different machines do not sync automatically; see the FAQ.)

init also installs an Agent Skill (a short instruction file that teaches skill-aware agents to use the CLI) for VS Code and Cursor, and for opencode in per-project MCP mode. With the opencode native plugin wired, no skill is installed there — the plugin already provides the memory tools, and a second instruction set only made agents chatty.

How it compares

Instruction files are great for a handful of standing rules — keep using them (open-memex can even draft one from your memories; see distill-agents below). open-memex covers the growing pile of decisions, lessons, and preferences that no one remembers to write down.

Installation

Requirements

• Node.js ≥ 22.14 (open-memex doctor verifies this for you). The floor is the SQLite driver's: better-sqlite3 13 is built against Node-API 10, which Node gained in 22.14.0 — older Node segfaults on the first database open.

Install the CLI

npm install -g open-memex

That's the stable release. Installing the package may print a reminder to run open-memex init — the editor wiring is a separate step (see Setting up your editor), so don't worry if you don't see the reminder; just run init next.

Two alternatives:

• No install — run via npx: npx -y open-memex runs any command without installing (e.g. npx -y open-memex init --client vscode). Slower to start, nothing to uninstall.
• Alpha builds (newest features, rougher edges, for testers): npm install -g open-memex@alpha. Check what's published with npm view open-memex version (stable) and npm view open-memex@alpha version (alpha).

If open-memex isn't found after installing, your PATH needs attention — see Troubleshooting.

From source (for contributors)

git clone -b main https://github.com/stoneskin/open-memex.git

cd open-memex npm install node --experimental-strip-types src/cli.ts

Setting up your editor

Run init from your project root (the top folder of the repo you're working in) so the project scope resolves to that repo:

open-memex init --yes

…or without installing the package first:

npx -y open-memex init --yes

--yes accepts the recommended defaults for everything init asks about (editors to wire, auto-capture, first-turn recall). Leave it off if you want to answer each question. With no --client, init detects your installed editors and wires them all — one init covers every project. Prefer a single editor? Pass --client:

VS Code (Copilot):

open-memex init --client vscode

Writes the MCP server entry; reload the window afterwards and confirm the open-memex server is started in Copilot Chat's MCP panel. By default this writes a project-level .vscode/mcp.json (an interactive run asks which level you want); add --global for VS Code's *user-level* config inst