Elasticsearch Knowledge Graph for MCP

Instructions

Implementation Reference

• src/index.ts:393-417 (schema)

  Input schema definition for the add_observations tool, defining parameters: name (string), observations (array of strings), memory_zone (string, required).

  {
    name: "add_observations",
    description: "Add observations to an existing entity in knowledge graph (memory)",
    inputSchema: {
      type: "object",
      properties: {
        name: {
          type: "string",
          description: "Name of entity to add observations to"
        },
        observations: {
          type: "array",
          items: {type: "string"},
          description: "Observations to add to the entity"
        },
        memory_zone: {
          type: "string",
          description: "Optional memory zone where the entity is stored. If not specified, uses the default zone."
        }
      },
      required: ["memory_zone", "name", "observations"],
      additionalProperties: false,
      "$schema": "http://json-schema.org/draft-07/schema#"
    }
  },

• src/index.ts:1032-1055 (handler)

  MCP server tool handler for 'add_observations': validates entity exists, calls kgClient.addObservations, returns formatted success/error response.

  else if (toolName === "add_observations") {
    const name = params.name;
    const observations = params.observations;
    const zone = params.memory_zone;
    
    // Get existing entity
    const entity = await kgClient.getEntity(name, zone);
    if (!entity) {
      const zoneMsg = zone ? ` in zone "${zone}"` : "";
      return formatResponse({
        success: false,
        error: `Entity "${name}" not found${zoneMsg}`,
        message: "Please create the entity before adding observations."
      });
    }
    
    // Add observations to the entity
    const updatedEntity = await kgClient.addObservations(name, observations, zone);
    
    return formatResponse({
      success: true,
      entity: updatedEntity
    });
  }

• src/kg-client.ts:1722-1746 (handler)

  Core implementation: fetches existing entity using getEntity, appends new observations, saves updated entity via saveEntity, returns the updated ESEntity.

  async addObservations(name: string, observations: string[], zone?: string): Promise<ESEntity> {
    const actualZone = zone || this.defaultZone;
    
    // Get existing entity
    const entity = await this.getEntity(name, actualZone);
    if (!entity) {
      throw new Error(`Entity "${name}" not found in zone "${actualZone}"`);
    }
    
    // Add new observations to the existing ones
    const updatedObservations = [
      ...entity.observations,
      ...observations
    ];
    
    // Update the entity
    const updatedEntity = await this.saveEntity({
      name: entity.name,
      entityType: entity.entityType,
      observations: updatedObservations,
      relevanceScore: entity.relevanceScore
    }, actualZone);
    
    return updatedEntity;
  }