mcp-prose-memory

Persistent memory for MCP clients.

mcp-prose-memory gives an agent a small, durable place to keep facts across sessions. It stores memory as JSON, keeps facts grouped by section, and exposes one tool for careful add, remove, replace, and view operations.

It is built for memory that should survive restarts without becoming a loose text file that slowly drifts out of shape.

Docs · Changelog · Contributing · Security

Features

• JSON memory storage with a stable schema

• Compact structured facts with optional key, value, source, and confidence

• Atomic writes through temp-file replacement

• Atomic fact operations: add, remove, replace, view

• Sectioned context organization for general clients and local assistant memory

• Case-insensitive duplicate detection

• Strict line-number validation for remove and replace

• Automatic normalization for older or partial JSON documents

• Compact memory_context output with section and character-budget filters

• Limits: 30 facts per section, 300 characters per fact, 80 characters per structured key

• Configurable storage path via environment variable

Related MCP server: agentsmd-memory

Installation

Full setup guide: Docs.

Runtime: Node >= 18. Node 20 or newer is recommended, since Node 18 is end-of-life. On Node 18, npm prints an EBADENGINE warning for @hono/node-server, a dependency of the MCP SDK's HTTP transport that this stdio server never loads. The warning is harmless, but installs with engine-strict=true (or Yarn 1) need Node 20+ or engine checks turned off.

npm install -g mcp-prose-memory

Or run with npx:

npx mcp-prose-memory

Configuration

Configuration reference: Docs.

Default storage is ~/.mcp-prose-memory/memory.json. Override it with MEMORY_PATH.

If you used an older release with a client-specific default memory location, either move that JSON file to the new default path or set MEMORY_PATH to the existing file.

Desktop Client

Add a server entry like this to your MCP client config:

{
  "mcpServers": {
    "memory": {
      "command": "npx",
      "args": ["mcp-prose-memory"]
    }
  }
}

CLI Client

Add a server entry like this to your CLI MCP config:

{
  "mcpServers": {
    "memory": {
      "command": "npx",
      "args": ["mcp-prose-memory"]
    }
  }
}

Custom Memory Location

{
  "mcpServers": {
    "memory": {
      "command": "npx",
      "args": ["mcp-prose-memory"],
      "env": {
        "MEMORY_PATH": "/path/to/your/memory.json"
      }
    }
  }
}

Memory File

The memory file is JSON with arrays of facts per section:

{
  "version": 5,
  "updated": "2025-01-15T10:30:00.000Z",
  "sections": {
    "work": ["Fact 1", "Fact 2"],
    "personal": ["Lives in Berlin", "Prefers dark mode"],
    "top_of_mind": [],
    "history": ["Completed project X"],
    "instructions": ["Be concise"],
    "user_preferences": [
      {
        "key": "answer_style",
        "value": "Prefers concise answers",
        "confidence": "high",
        "source": "user_explicit",
        "createdAt": "2025-01-15T10:30:00.000Z",
        "updatedAt": "2025-01-15T10:30:00.000Z"
      }
    ]
  }
}

If the file does not exist, the server starts with an empty document. If the file is invalid JSON, the server fails the operation instead of wiping memory.

Tools

Tools reference: Docs.

memory

Single tool for all memory operations. The command parameter selects the action.

Commands:

view

Show all memories or filter by section.

{"command": "view"}
{"command": "view", "section": "work"}

add

Add a fact to a section.

{"command": "add", "section": "personal", "fact": "Lives in Berlin"}

Structured compact facts are also supported:

{"command": "add", "section": "user_preferences", "key": "answer_style", "value": "Prefers concise answers"}

upsert

Add a structured fact or replace the existing fact with the same key.

{"command": "upsert", "section": "user_preferences", "key": "answer_style", "value": "Prefers concise and direct answers"}

remove

Remove a fact by line number.

{"command": "remove", "section": "work", "line": 3}

replace

Update a fact by line number.

{"command": "replace", "section": "top_of_mind", "line": 1, "fact": "Working on new project"}

memory_context

Returns memory for session initialization. Clients can request compact bounded context.

{}

{"format": "compact", "sections": ["user_profile", "user_preferences"], "maxChars": 1500}

Sections

Development

git clone https://github.com/gabrimatic/mcp-prose-memory.git
cd mcp-prose-memory
npm ci
npm test
npm run check

npm test builds the TypeScript source and runs store-level plus real MCP stdio smoke tests. npm run check also runs a production dependency audit and verifies the npm package contents with npm pack --dry-run.

prepublishOnly runs the same check before publishing.

Project Support

• Changes: CHANGELOG.md

• Contributions: CONTRIBUTING.md

• Security reports: SECURITY.md

• Issues: GitHub Issues

Developer

By Soroush

License

MIT