Developer Resources

Calculate Endpoint

• URL: /api/calculate
• Method: POST
• Content-Type: application/json

Request Body

The request body must be a JSON object containing the following numeric fields:

• carPrice: The total price of the car.
• downPayment: The initial amount paid upfront.
• loanTerm: The duration of the loan in months.
• interestRate: The annual interest rate in percent (e.g., 5.95).
• balloonPayment: The residual value of the car at the end of the loan term.
• setupFee: A one-time fee for setting up the loan.
• monthlyFee: The administrative fee charged each month.

Example Request:

{
  "carPrice": 300000,
  "downPayment": 60000,
  "loanTerm": 36,
  "interestRate": 5.95,
  "balloonPayment": 150000,
  "setupFee": 695,
  "monthlyFee": 60
}

Success Response

On a successful calculation, the API will return a JSON object with the following fields:

• monthlyPayment: The calculated monthly payment, including the monthly fee.
• firstPayment: The first payment, which includes the monthly payment and the setup fee.
• totalInterest: The total amount of interest paid over the life of the loan.
• totalCost: The total cost of the loan, including principal, interest, and all fees.
• aprc: The Annual Percentage Rate of Charge (effective interest rate).
• principal: The initial loan amount (carPrice - carPrice).

Example Response:

{
  "monthlyPayment": 2950.56,
  "firstPayment": 3645.56,
  "totalInterest": 31220.16,
  "totalCost": 273380.16,
  "aprc": 7.8,
  "principal": 240000
}

Error Response

If the request is malformed (e.g., missing fields, invalid JSON), the API will return a 400 Bad Request status with an error message.

Example Error:

{
  "error": "Missing or invalid field: carPrice"
}