AWS MCP Server

Instructions

Implementation Reference

• src/index.ts:1007-1041 (handler)

  Executes the get_cost_breakdown tool. Fetches AWS cost data using CostExplorerClient's GetCostAndUsageCommand. Groups by SERVICE (default) or USAGE_TYPE if service_name provided. Returns daily breakdown sorted by cost descending, top 100 items.

  if (name === "get_cost_breakdown") {
      const endDate = (args as any)?.end_date || new Date().toISOString().split('T')[0];
      const startDate = (args as any)?.start_date || new Date(Date.now() - 14 * 24 * 60 * 60 * 1000).toISOString().split('T')[0];
      const serviceName = (args as any)?.service_name;
  
      const groupByKey = serviceName ? "USAGE_TYPE" : "SERVICE";
      const filter = serviceName
          ? { Dimensions: { Key: "SERVICE", Values: [serviceName] } } as any
          : undefined;
  
      const command = new GetCostAndUsageCommand({
          TimePeriod: { Start: startDate, End: endDate },
          Granularity: "DAILY",
          Metrics: ["UnblendedCost"],
          GroupBy: [{ Type: "DIMENSION", Key: groupByKey }],
          Filter: filter
      });
  
      const response = await costExplorerClient.send(command);
  
      const costs = response.ResultsByTime?.flatMap(r =>
          r.Groups?.map(g => ({
              Date: r.TimePeriod?.Start,
              [groupByKey === "USAGE_TYPE" ? "UsageType" : "Service"]: g.Keys?.[0],
              Cost: parseFloat(g.Metrics?.UnblendedCost?.Amount || "0").toFixed(4),
              Unit: g.Metrics?.UnblendedCost?.Unit
          }))
      )
          .filter(c => c && parseFloat(c.Cost) > 0) // Filter out zero costs
          .sort((a, b) => parseFloat(b?.Cost || "0") - parseFloat(a?.Cost || "0")) || [];
  
      return {
          content: [{ type: "text", text: JSON.stringify(costs.slice(0, 100), null, 2) }]
      };
  }

• src/index.ts:209-218 (schema)

  Input schema definition for the get_cost_breakdown tool, defining parameters for date range and optional service_name.

  name: "get_cost_breakdown",
  description: "Detailed cost analysis. If service_name is provided, breaks down that service by Usage Type. Otherwise, breaks down by Service.",
  inputSchema: {
      type: "object",
      properties: {
          start_date: { type: "string", description: "Start date in YYYY-MM-DD format (default: 14 days ago)." },
          end_date: { type: "string", description: "End date in YYYY-MM-DD format." },
          service_name: { type: "string", description: "Optional: Specific service to analyze (e.g., 'Amazon Elastic Compute Cloud - Compute')." }
      }
  }

• src/index.ts:208-219 (registration)

  Registers the get_cost_breakdown tool in the ListTools response with name, description, and input schema.

  {
      name: "get_cost_breakdown",
      description: "Detailed cost analysis. If service_name is provided, breaks down that service by Usage Type. Otherwise, breaks down by Service.",
      inputSchema: {
          type: "object",
          properties: {
              start_date: { type: "string", description: "Start date in YYYY-MM-DD format (default: 14 days ago)." },
              end_date: { type: "string", description: "End date in YYYY-MM-DD format." },
              service_name: { type: "string", description: "Optional: Specific service to analyze (e.g., 'Amazon Elastic Compute Cloud - Compute')." }
          }
      }
  },

• src/index.ts:58-58 (helper)

  Initializes the AWS CostExplorerClient used by the get_cost_breakdown handler.

  const costExplorerClient = new CostExplorerClient({});