curl --request POST \
  --url https://api.iotools.cloud/v1/tool/simple-interest-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "principal": "10000",
  "rate": "5",
  "time": "3",
  "timeUnit": "years",
  "currency": "USD"
}
'

{
  "tool": "simple-interest-calculator",
  "tool_version": "1.0.1",
  "outputs": {
    "summary": [
      {
        "metric": "Principal Amount",
        "value": "$10,000.00"
      },
      {
        "metric": "Annual Interest Rate",
        "value": "5.0%"
      },
      {
        "metric": "Time Period",
        "value": "3 years (3.0000 years)"
      },
      {
        "metric": "Total Interest",
        "value": "$1,500.00"
      },
      {
        "metric": "Total Amount",
        "value": "$11,500.00"
      }
    ],
    "schedule": [
      {
        "year": "1",
        "interest-this-year": "$500.00",
        "cumulative-interest": "$500.00",
        "balance": "$10,500.00"
      },
      {
        "year": "2",
        "interest-this-year": "$500.00",
        "cumulative-interest": "$1,000.00",
        "balance": "$11,000.00"
      },
      {
        "year": "3",
        "interest-this-year": "$500.00",
        "cumulative-interest": "$1,500.00",
        "balance": "$11,500.00"
      }
    ]
  },
  "credits_used": 3,
  "credits_remaining": null
}