Knowledge Graph Memory Server

Instructions

Implementation Reference

• index.ts:157-181 (handler)

  The core handler function that executes the search_nodes tool logic: loads the knowledge graph, filters entities matching the query in name, entityType, or observations, filters relations between those entities, and returns the filtered subgraph.

  async searchNodes(query: string): Promise<KnowledgeGraph> {
    const graph = await this.loadGraph();
  
    // Filter entities
    const filteredEntities = graph.entities.filter(e =>
      e.name.toLowerCase().includes(query.toLowerCase()) ||
      e.entityType.toLowerCase().includes(query.toLowerCase()) ||
      e.observations.some(o => o.toLowerCase().includes(query.toLowerCase()))
    );
  
    // Create a Set of filtered entity names for quick lookup
    const filteredEntityNames = new Set(filteredEntities.map(e => e.name));
  
    // Filter relations to only include those between filtered entities
    const filteredRelations = graph.relations.filter(r =>
      filteredEntityNames.has(r.from) && filteredEntityNames.has(r.to)
    );
  
    const filteredGraph: KnowledgeGraph = {
      entities: filteredEntities,
      relations: filteredRelations,
    };
  
    return filteredGraph;
  }

• index.ts:531-532 (registration)

  Registration and dispatch logic in the CallToolRequest handler switch statement, which calls the searchNodes method with the provided query argument.

  case "search_nodes":
    return { content: [{ type: "text", text: JSON.stringify(await knowledgeGraphManager.searchNodes(args.query as string), null, 2) }] };

• index.ts:429-438 (schema)

  Tool schema definition including name, description, and input schema requiring a 'query' string parameter, registered in the ListTools response.

    name: "search_nodes",
    description: "Search for nodes in the knowledge graph based on a query",
    inputSchema: {
      type: "object",
      properties: {
        query: { type: "string", description: "The search query to match against entity names, types, and observation content" },
      },
      required: ["query"],
    },
  },