Weasley DeepMind

Weasley DeepMind is a self-hosted memory server for AI agents. It stores small, typed memory fragments, links related evidence, and recalls the right context through MCP without forcing an entire conversation history back into every prompt.

It is part of the Weasley Open Source family and is released under Apache-2.0.

Why DeepMind

• Useful recall, not a transcript dump. Keyword, PostgreSQL GIN, graph-neighbor, and optional pgvector search are merged and ranked within a token budget.

• Memory with structure. Facts, decisions, procedures, preferences, episodes, and errors keep provenance, importance, links, and lifecycle state.

• MCP-native. Use a local stdio process or the Streamable HTTP endpoint at /mcp.

• Fail-closed HTTP security. The HTTP server rejects requests when no access key is configured. Authentication can only be disabled explicitly for local development.

• Self-hosted data. PostgreSQL is the system of record. Redis and external embedding or LLM providers are optional.

• Operationally ready. Migrations are serialized with a PostgreSQL advisory lock, secrets are redacted from logs, and updates refuse dirty Git checkouts.

Related MCP server: elephantasm-mcp

Requirements

• Node.js 20.19 or newer

• PostgreSQL 15 or newer with the pgvector extension

• Redis 7 (optional, for cache and low-latency keyword lookup)

Install from npm

npm install --global weasley-deepmind

Create a PostgreSQL database with pgvector, then configure the connection:

export DATABASE_URL='postgresql://postgres:password@localhost:5432/weasley_deepmind'
export WEASLEY_DEEPMIND_ACCESS_KEY='replace-with-a-long-random-secret'

weasley-deepmind migrate
weasley-deepmind serve

The HTTP server listens on http://127.0.0.1:57332 by default. Its MCP endpoint is http://127.0.0.1:57332/mcp.

Add it to an MCP client

The npm package includes a newline-delimited stdio transport. A generic MCP client configuration looks like this:

{
  "mcpServers": {
    "weasley-deepmind": {
      "command": "npx",
      "args": ["-y", "weasley-deepmind", "stdio"],
      "env": {
        "DATABASE_URL": "postgresql://postgres:password@localhost:5432/weasley_deepmind",
        "WEASLEY_DEEPMIND_AUTO_MIGRATE": "true"
      }
    }
  }
}

For an already-running HTTP deployment, point the client at /mcp and send Authorization: Bearer <WEASLEY_DEEPMIND_ACCESS_KEY>.

Run the repository locally

git clone https://github.com/potatohoney-p/weasley-deepmind.git
cd weasley-deepmind
npm ci
docker compose -f docker-compose.dev.yml up -d
cp .env.example.minimal .env
npm run migrate
npm start

The development Compose file exposes PostgreSQL at localhost:35432 and Redis at localhost:36379. Update .env to match those ports before starting the server.

Core flow

flowchart LR
    Agent["AI agent"] --> MCP["stdio or Streamable HTTP"]
    MCP --> Tools["remember · recall · reflect · context"]
    Tools --> Rank["keyword + graph + vector ranking"]
    Rank --> Postgres["PostgreSQL + pgvector"]
    Rank -. optional cache .-> Redis["Redis"]

The main tool set includes remember, batch_remember, recall, forget, amend, link, reflect, context, memory_stats, memory_consolidate, graph_explore, fragment_history, reconstruct_history, and search_traces. Tool availability can be limited by API-key permissions and operating mode.

Configuration

See .env.example, configuration, and the installation guide for the complete matrix.

Local transformer embeddings are intentionally excluded from the default install so the core MCP server does not inherit an optional native-image dependency. Follow the pinned setup in docs/embedding-local.md before selecting EMBEDDING_PROVIDER=transformers.

CLI

weasley-deepmind serve       Start the HTTP MCP server
weasley-deepmind stdio       Start the local stdio MCP server
weasley-deepmind migrate     Apply pending database migrations
weasley-deepmind health      Check database, Redis, and embeddings
weasley-deepmind recall      Search memory from the terminal
weasley-deepmind remember    Store a memory fragment
weasley-deepmind update      Preview or apply an update

Run weasley-deepmind --help or see the CLI reference for every command.

Security defaults

• Keep the HTTP listener on loopback unless you have a trusted reverse proxy and an explicit origin allowlist.

• Use a unique, high-entropy WEASLEY_DEEPMIND_ACCESS_KEY and never commit .env.

• Stdio mode trusts the local MCP host process; protect the host account and database credentials accordingly.

• Report vulnerabilities privately using the instructions in SECURITY.md.

Development

npm ci
npm test
npm run lint
npm run lint:migrations
npm pack --dry-run

Architecture and operations details live in docs/architecture.en.md and docs/operations. Contributions are welcome through CONTRIBUTING.md.

License

Copyright 2026 Weasley Open Source.

Licensed under the Apache License 2.0. See NOTICE for attribution information.