MCP Think Tank

Instructions

Implementation Reference

• src/memory/tools.ts:414-441 (handler)

  The execute function that implements the core logic of the search_nodes tool. It performs direct matching on entity names, queries the memory store for observation matches, combines results, retrieves full entities, and returns a JSON string with the findings.

  execute: async (args) => {
    // First, check if any entity names directly match or contain the query
    const directMatches = Array.from(graph.entities.keys()).filter(name => 
      name.toLowerCase().includes(args.query.toLowerCase())
    );
    
    // Then use the query interface to search observations
    const queryResults = await memoryStore.query({
      keyword: args.query,
      limit: 100
    });
    
    // Combine direct entity name matches with observation content matches
    const entityNames = new Set<string>([
      ...directMatches,
      ...queryResults.map(result => result.entityName)
    ]);
    
    // Get the full entities
    const results = graph.getEntities(Array.from(entityNames));
    
    // Return as string
    return JSON.stringify({
      entities: results,
      count: results.length,
      message: `Found ${results.length} matching entities.`
    });
  }

• src/memory/tools.ts:410-442 (registration)

  Registers the search_nodes tool with the FastMCP server inside the registerMemoryTools function, specifying name, description, input schema, and inline handler.

  server.addTool({
    name: 'search_nodes',
    description: 'Search for nodes in the knowledge graph based on a query',
    parameters: Schemas.SearchNodesSchema,
    execute: async (args) => {
      // First, check if any entity names directly match or contain the query
      const directMatches = Array.from(graph.entities.keys()).filter(name => 
        name.toLowerCase().includes(args.query.toLowerCase())
      );
      
      // Then use the query interface to search observations
      const queryResults = await memoryStore.query({
        keyword: args.query,
        limit: 100
      });
      
      // Combine direct entity name matches with observation content matches
      const entityNames = new Set<string>([
        ...directMatches,
        ...queryResults.map(result => result.entityName)
      ]);
      
      // Get the full entities
      const results = graph.getEntities(Array.from(entityNames));
      
      // Return as string
      return JSON.stringify({
        entities: results,
        count: results.length,
        message: `Found ${results.length} matching entities.`
      });
    }
  });

• src/utils/validation.ts:61-63 (schema)

  Zod schema defining the input parameters for the search_nodes tool: a required 'query' string.

  export const SearchNodesSchema = z.object({
    query: z.string().min(1).describe('Search query to find matching entities')
  });