Marra Local Memory MCP

Secure local MCP server for encrypted memory files.

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English

What it does

Marra Local Memory MCP is a local stdio MCP server for reading and updating a small allow-listed set of encrypted memory files.

It exposes exactly three tools:

• memory_status — returns encryption state and revisions;

• memory_get — decrypts and reads a registered memory file;

• memory_update — encrypts and atomically updates a file with revision locking.

Requirements

• Windows

• Node.js 22 or newer

• npm 11 or newer

Check the installed versions:

node --version
npm --version

Installation

Open PowerShell in MCP_tool:

npm install
npm run setup

npm run setup creates the local RSA key pair, encrypted files, and the local cache. The private key remains local and is excluded from Git.

Start

Run the server over stdio:

npm start

The server does not open an HTTP port. Your MCP client starts it as a child process.

The ready-to-use connection configuration is in mcp.json:

{
  "mcpServers": {
    "marra-local-memory": {
      "command": "node",
      "args": ["D:\\Marra\\MCP_tool\\src\\server.js"],
      "cwd": "D:\\Marra\\MCP_tool"
    }
  }
}

Copy this configuration into the configuration file of your MCP client.

Tool input

Read a registered file:

{
  "file_id": "memory"
}

Update it using the current revision:

{
  "file_id": "memory",
  "content": "New content",
  "expected_revision": 0
}

Allowed IDs are memory and shared_data. Stale writes return REVISION_CONFLICT; read the latest revision and retry the update.

Security model

• Content is encrypted with AES-256-GCM.

• AES keys are wrapped with RSA-OAEP-SHA256.

• Tools accept registered file_id values only, never arbitrary paths.

• Absolute paths, .., symlinks, and arbitrary extensions are not exposed through the MCP API.

• Writes use atomic replacement and a local write queue.

• Private keys, encrypted runtime data, and decrypted cache files are excluded from Git.

• Never share or commit storage/keys/private.pem.

Tests

npm test
npm audit --omit=dev

Русский

Локальный stdio MCP-сервер для чтения и обновления зарегистрированных зашифрованных memory-файлов.

Доступны три инструмента:

• memory_status — состояние шифрования и ревизии;

• memory_get — расшифровка и чтение файла;

• memory_update — шифрование и атомарное обновление с проверкой ревизии.

Установка и запуск

В PowerShell из папки MCP_tool:

npm install
npm run setup
npm start

Конфигурация подключения находится в mcp.json. Скопируйте её в настройки MCP-клиента.

Разрешены только file_id: memory и shared_data. Произвольные пути, абсолютные пути и .. не принимаются.

Данные шифруются AES-256-GCM, AES-ключи — RSA-OAEP-SHA256. Приватный ключ нельзя передавать или добавлять в Git.

Проверка

npm test
npm audit --omit=dev