Graph Memory RAG MCP Server

A Model Context Protocol (MCP) server implementation that provides graph-based memory storage capabilities. This server allows AI agents to store and retrieve information in a graph structure, making it ideal for maintaining context and relationships between different pieces of information.

Features

• In-memory graph database storage
• Entity creation and management
• Relationship creation between entities
• Query capabilities for both entities and relationships
• Delete operations with cascading relationship cleanup
• MCP-compliant interface

Installation

npm install

Dependencies

• @modelcontextprotocol/sdk: ^1.0.3
• zod: ^3.22.4

Usage

Start the server:

node app.js

API Tools

Create Entity

Creates a new entity in the graph database.

• Parameters:
  • name: string
  • entityType: string
  • observations: string[]

Create Relationship

Creates a relationship between two existing entities.

• Parameters:
  • fromEntityName: string
  • toEntityName: string
  • relationType: string

Query Entities

Retrieves entities by type.

• Parameters:
  • entityType: string

Query Relationships

Retrieves relationships by type.

• Parameters:
  • relationType: string

Delete Entity

Deletes an entity and its associated relationships.

• Parameters:
  • name: string

Implementation Details

The server uses an in-memory graph database with two main components:

1. Entities Map: Stores entity objects with their properties
2. Relationships Map: Stores relationship objects connecting entities

Each entity contains:

• id: Unique identifier
• name: Entity name
• type: Entity type
• observations: Array of strings containing information about the entity

Each relationship contains:

• id: Unique identifier
• fromId: Source entity ID
• toId: Target entity ID
• type: Relationship type

Contributing

Feel free to open issues or submit pull requests for improvements.

License

MIT