AWS MCP Audit

Implementation Reference

• src/aws_mcp_audit/server.py:216-220 (handler)

  Handler and registration for the 'cost_explorer_by_service' tool using @mcp.tool decorator. Builds AWS session and delegates to cost_explorer_by_dimension with SERVICE dimension.

  @mcp.tool
  def cost_explorer_by_service(days: int = 30, top_n: int = 10, auth: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
      session = build_boto3_session(auth)
      return cost_explorer_by_dimension(session, days=days, dimension="SERVICE", top_n=top_n)

• src/aws_mcp_audit/collectors/cost_explorer.py:29-58 (helper)

  Core helper function implementing AWS Cost Explorer query grouped by dimension (e.g., SERVICE), extracts top N services by UnblendedCost, handles errors and parsing.

  def cost_explorer_by_dimension(session: boto3.Session, days: int, dimension: str, top_n: int = 10) -> Dict[str, Any]:
      ce = session.client("ce", region_name="us-east-1")
      rng = _dates(days)
      try:
          resp = ce.get_cost_and_usage(
              TimePeriod=rng,
              Granularity="MONTHLY" if days >= 28 else "DAILY",
              Metrics=["UnblendedCost"],
              GroupBy=[{"Type": "DIMENSION", "Key": dimension}],
          )
          groups = []
          for t in resp.get("ResultsByTime", []):
              for g in t.get("Groups", []):
                  groups.append(
                      {
                          "keys": g.get("Keys", []),
                          "amount": (g.get("Metrics", {}).get("UnblendedCost", {}) or {}).get("Amount"),
                          "unit": (g.get("Metrics", {}).get("UnblendedCost", {}) or {}).get("Unit"),
                      }
                  )
          # naive top_n by amount
          def amt(x):
              try:
                  return float(x.get("amount") or 0.0)
              except Exception:
                  return 0.0
          groups.sort(key=amt, reverse=True)
          return {"time_period": rng, "dimension": dimension, "top": groups[:top_n]}
      except ClientError as e:
          return {"time_period": rng, "dimension": dimension, "error": str(e), "top": []}

• src/aws_mcp_audit/collectors/cost_explorer.py:9-12 (helper)

  Helper utility to compute Start/End dates for Cost Explorer queries.

  def _dates(days: int) -> Dict[str, str]:
      end = datetime.date.today()
      start = end - datetime.timedelta(days=days)
      return {"Start": start.isoformat(), "End": end.isoformat()}