Neo4j Agent Memory MCP Server

Instructions

Implementation Reference

• src/handlers/index.ts:235-248 (handler)

  The handler function executes the update_memory tool by validating arguments with isUpdateMemoryArgs and calling neo4j.updateNode to update the memory node in the database.

  case 'update_memory': {
    if (!isUpdateMemoryArgs(args)) {
      throw new McpError(ErrorCode.InvalidParams, 'Invalid update_memory arguments');
    }
    const result = await neo4j.updateNode(args.nodeId, args.properties);
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(result, null, 2),
        },
      ],
    };
  }

• src/types.ts:29-84 (schema)

  TypeScript interface and validation function defining the input schema for update_memory tool arguments.

  export interface UpdateMemoryArgs {
    nodeId: number;
    properties: Record<string, any>;
  }
  
  export interface UpdateConnectionArgs {
    fromMemoryId: number;
    toMemoryId: number;
    type: string;
    properties: Record<string, any>;
  }
  
  export interface DeleteMemoryArgs {
    nodeId: number;
  }
  
  export interface DeleteConnectionArgs {
    fromMemoryId: number;
    toMemoryId: number;
    type: string;
  }
  
  export interface ListMemoryLabelsArgs {
    // No arguments needed for this tool
  }
  
  export function isCreateMemoryArgs(args: unknown): args is CreateMemoryArgs {
    return typeof args === 'object' && args !== null && typeof (args as CreateMemoryArgs).label === 'string' && typeof (args as CreateMemoryArgs).properties === 'object';
  }
  
  export function isSearchMemoriesArgs(args: unknown): args is SearchMemoriesArgs {
    if (typeof args !== 'object' || args === null) return false;
    const searchArgs = args as SearchMemoriesArgs;
    if (searchArgs.query !== undefined && typeof searchArgs.query !== 'string') return false;
    if (searchArgs.since_date !== undefined && typeof searchArgs.since_date !== 'string') return false;
    return true;
  }
  
  export function isCreateConnectionArgs(args: unknown): args is CreateConnectionArgs {
    return (
      typeof args === 'object' &&
      args !== null &&
      typeof (args as CreateConnectionArgs).fromMemoryId === 'number' &&
      typeof (args as CreateConnectionArgs).toMemoryId === 'number' &&
      typeof (args as CreateConnectionArgs).type === 'string'
    );
  }
  
  export function isUpdateMemoryArgs(args: unknown): args is UpdateMemoryArgs {
    return (
      typeof args === 'object' &&
      args !== null &&
      typeof (args as UpdateMemoryArgs).nodeId === 'number' &&
      typeof (args as UpdateMemoryArgs).properties === 'object'
    );
  }

• src/tools/definitions.ts:91-109 (registration)

  Tool registration in the tools array, including name, description, and input schema for the MCP server.

  {
    name: 'update_memory',
    description: 'Update properties of an existing memory such as adding more detail or make a change when you find out something new',
    inputSchema: {
      type: 'object',
      properties: {
        nodeId: {
          type: 'number',
          description: 'ID of the memory to update',
        },
        properties: {
          type: 'object',
          description: 'Properties to update/add',
          additionalProperties: true,
        },
      },
      required: ['nodeId', 'properties'],
    },
  },