Elasticsearch Knowledge Graph for MCP

Instructions

Implementation Reference

• src/index.ts:447-471 (registration)

  Registration of the get_recent tool in the listTools response, including name, description, and input schema.

  {
    name: "get_recent",
    description: "Get recently accessed entities from knowledge graph (memory) and their relations",
    inputSchema: {
      type: "object",
      properties: {
        limit: {
          type: "integer",
          description: "Max results (default: 20 if includeObservations is false, 5 if true)"
        },
        includeObservations: {
          type: "boolean",
          description: "Whether to include full entity observations in results (default: false)",
          default: false
        },
        memory_zone: {
          type: "string",
          description: "Optional memory zone to get recent entities from. If not specified, uses the default zone."
        }
      },
      required: ["memory_zone"],
      additionalProperties: false,
      "$schema": "http://json-schema.org/draft-07/schema#"
    }
  },

• src/index.ts:1082-1097 (handler)

  Handler for executing the get_recent tool call, parses arguments, invokes kgClient.getRecentEntities, and formats response.

  else if (toolName === "get_recent") {
    const limit = params.limit || 20;
    const includeObservations = params.includeObservations ?? false;
    const zone = params.memory_zone;
    
    const recentEntities = await kgClient.getRecentEntities(limit, includeObservations, zone);
    
    return formatResponse({
      entities: recentEntities.map(e => ({
        name: e.name,
        entityType: e.entityType,
        observations: e.observations
      })),
      total: recentEntities.length
    });
  }

• src/kg-client.ts:1836-1858 (helper)

  Helper method getRecentEntities in KnowledgeGraphClient that implements the core logic by searching all entities sorted by lastRead timestamp (recency).

  async getRecentEntities(limit: number, includeObservations: boolean, zone?: string): Promise<ESEntity[]> {
    const actualZone = zone || this.defaultZone;
    
    // Search with empty query but sort by recency
    const searchParams: ESSearchParams = {
      query: "*", // Use wildcard instead of empty query to match all documents
      limit: limit,
      sortBy: 'recent', // Sort by recency
      includeObservations
    };
    
    // Add zone if specified
    if (actualZone) {
      (searchParams as any).zone = actualZone;
    }
    
    const results = await this.search(searchParams);
    
    // Filter to only include entities
    return results.hits.hits
      .filter((hit: any) => hit._source.type === 'entity')
      .map((hit: any) => hit._source);
  }