Graphmind MCP Server

graphmind

graphmind is a small, durable memory for agents: a knowledge graph you can build up a fact at a time and query back later. You record entities — people, places, projects, anything with a name — each with a type and a growing list of plain-text observations, and you connect them with typed relations ("Alice — lives_in → Lisbon"). The whole graph lives in one JSON file on disk, so the memory survives restarts and stays readable, diffable, and editable by hand.

There is no database to run and no service to sign up for. The graph file is the product.

Install

npx @reneturcios/graphmind read

Or run the container image:

docker run -i ghcr.io/cloudcorprecords/graphmind

The container defaults to the MCP server (see below). Pass CLI arguments to use it as a CLI instead. If you run the container, mount a volume over the working directory if you want the graph file to persist between runs.

Where the graph lives

The store file path comes from the GRAPHMIND_FILE environment variable and defaults to ./graphmind.json in the current working directory. The file is loaded when the server (or a CLI command) starts, and it is rewritten after every change, so what is on disk is always the full current graph:

{
  "entities": [
    { "name": "Alice", "entityType": "person", "observations": ["Lives in Lisbon"] }
  ],
  "relations": [
    { "from": "Alice", "to": "Lisbon", "relationType": "lives_in" }
  ]
}

CLI

The CLI is a read/inspect face over the same store file the MCP server writes:

# Print the whole graph as JSON
graphmind read

# Print the subgraph matching a search term
graphmind search lisbon

# Point at a specific store file
GRAPHMIND_FILE=~/notes/graph.json graphmind read

graphmind --version

Exit codes: 0 on success, 1 when the store cannot be read or written, 2 for usage errors.

MCP server

One bin serves both faces. The mcp subcommand starts a stdio MCP server:

npx -y @reneturcios/graphmind mcp

MCP client configuration:

{
  "mcpServers": {
    "graphmind": {
      "command": "npx",
      "args": ["-y", "@reneturcios/graphmind", "mcp"],
      "env": { "GRAPHMIND_FILE": "/path/to/graphmind.json" }
    }
  }
}

Tools

Behaviour worth knowing

• Names are identity. An entity is its name; creating a second entity with the same name does nothing. Rename by deleting and recreating.
• Relations need real endpoints. create_relations requires both the from and to entities to already exist, and fails the whole call if one is missing — no stub entities are invented, so a typo surfaces immediately instead of quietly corrupting the graph.
• Observations are a set, in order. Adding a string an entity already carries is a no-op; new strings append in the order given.
• Deletes cascade only from entities. Deleting an entity removes its relations; deleting observations or relations never touches anything else.

Development

npm install
npm run build   # tsc -> dist/
npm test        # node test runner over test/*.test.ts, no network
npm run dev     # run the CLI from source via tsx

License

MIT — see LICENSE.