RAG MCP Server

Instructions

Implementation Reference

• build/tools/graph/search-nodes.js:24-41 (handler)

  The searchNodesHandler function implements the core logic of the 'search_nodes' tool. It validates the query input, calls knowledgeGraphManager.searchNodes, formats the result as JSON text content, and handles errors.

  export const searchNodesHandler = async (args) => {
      if (!args.query || typeof args.query !== 'string') {
          throw new Error("The 'query' parameter is required and must be a string");
      }
      try {
          const results = await knowledgeGraphManager.searchNodes(args.query);
          return {
              content: [{
                      type: "text",
                      text: JSON.stringify(results, null, 2)
                  }]
          };
      }
      catch (error) {
          console.error("Error in search_nodes tool:", error);
          throw error;
      }
  };

• build/tools/graph/search-nodes.js:7-20 (schema)

  The input schema and metadata definition for the 'search_nodes' tool, specifying the required 'query' string parameter.

  export const searchNodesTool = {
      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"],
      },
  };

• build/tools/graph/register-graph-tools-batch3.js:20-26 (registration)

  Explicit registration of the 'search_nodes' tool and its handler into the toolRegistry.

  // Enregistrer search_nodes
  try {
      toolRegistry.register(searchNodesTool, searchNodesHandler);
      console.log(`✅ Outil enregistré: ${searchNodesTool.name}`);
  }
  catch (error) {
      console.error(`❌ Erreur lors de l'enregistrement de ${searchNodesTool.name}:`, error);

• build/knowledge-graph/manager.js:97-112 (helper)

  The core searchNodes method in KnowledgeGraphManager that performs the actual node searching by filtering entities and relations based on the query matching names, types, or observations case-insensitively.

  async searchNodes(query) {
      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 = {
          entities: filteredEntities,
          relations: filteredRelations,
      };
      return filteredGraph;
  }

• build/core/registry.js:218-219 (registration)

  The 'search_nodes' tool is listed in the expected tools array for verification in the auto-registry system.

  'search_nodes',
  'open_nodes',