curl --request POST \
  --url https://api.iotools.cloud/v1/tool/effective-interest-rate-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "nominalRate": "6",
  "compoundingFrequency": "12"
}
'

{
  "tool": "effective-interest-rate-calculator",
  "tool_version": "1.0.2",
  "outputs": {
    "summary": [
      {
        "metric": "Nominal Annual Rate",
        "value": "6.0%"
      },
      {
        "metric": "Compounding Frequency",
        "value": "Monthly (12x/year)"
      },
      {
        "metric": "Effective Annual Rate (EAR)",
        "value": "6.2%"
      },
      {
        "metric": "Difference (EAR − Nominal)",
        "value": "0.2%"
      }
    ]
  },
  "credits_used": 5,
  "credits_remaining": null
}