What does the Mortgage Calculator API do?

Monthly payment, total interest, LTV, and optional amortization schedule. Use it when you need exact JSON instead of asking an LLM to recreate well-defined utility logic.

How much does one call to Mortgage Calculator cost?

5 credits per successful call. Failed calls (validation errors, 5xx) don't bill.

What parameters does the Mortgage Calculator API require?

Required fields: home_price, down_payment, annual_rate_percent, years. Full schema at /v1/openapi.json.

Is the Mortgage Calculator API deterministic?

Yes — same input, same output, forever. Tool version 2026-04-22; output shape is stable within a major version.

Can an AI agent call the Mortgage Calculator API?

Yes. Connect to https://api.miniwebtool.com/v1/mcp over the Model Context Protocol. The agent discovers `mortgage-calculator` with its JSON Schema automatically, so the model can plan while MiniWebtool handles the exact tool result.

What format does the API return?

JSON with a stable envelope: `{request_id, tool, tool_version, credits_used, result}`. Errors are RFC 7807 `application/problem+json`.

Mortgage Calculator API

Endpoint

POST https://api.miniwebtool.com/v1/tools/mortgage-calculator/run

Request body

Field	Type	Req.
`home_price`	`float`	✓
`down_payment`	`float`	✓
`annual_rate_percent`	`float`	✓
`years`	`float`	✓
`include_schedule`	`bool`	—
`property_tax_annual`	`float`	—
`home_insurance_annual`	`float`	—
`pmi_annual_percent`	`float`	—

Cost & access

5 credits per successful call.
Max payload: 4096 bytes.
Privacy mode: hash_only
Available on: pro, business, scale

Response envelope

{
  "request_id": "01K...",
  "tool": "mortgage-calculator",
  "tool_version": "2026-04-22",
  "credits_used": 5,
  "result": { ... }
}

Try it

API key *

Stored only in this browser tab. Don't have one? Start Pro →

home_price (float) *

down_payment (float) *

annual_rate_percent (float) *

years (float) *

include_schedule (bool)

property_tax_annual (float)

home_insurance_annual (float)

pmi_annual_percent (float)

Response

Response headers

Code examples

curl -X POST https://api.miniwebtool.com/v1/tools/mortgage-calculator/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"home_price":500000,"down_payment":100000,"annual_rate_percent":6.5,"years":30}'

import requests

resp = requests.post(
    'https://api.miniwebtool.com/v1/tools/mortgage-calculator/run',
    headers={'Authorization': 'Bearer mwt_live_YOUR_KEY'},
    json={'home_price': 500000, 'down_payment': 100000, 'annual_rate_percent': 6.5, 'years': 30},
)
resp.raise_for_status()
print(resp.json())

const resp = await fetch(
  'https://api.miniwebtool.com/v1/tools/mortgage-calculator/run',
  {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer mwt_live_YOUR_KEY',
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({"home_price":500000,"down_payment":100000,"annual_rate_percent":6.5,"years":30}),
  }
);
const data = await resp.json();
console.log(data);

<?php
$ch = curl_init('https://api.miniwebtool.com/v1/tools/mortgage-calculator/run');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer mwt_live_YOUR_KEY',
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => json_encode([
    'home_price' => 500000,
    'down_payment' => 100000,
    'annual_rate_percent' => 6.5,
    'years' => 30
]),
]);
$resp = curl_exec($ch);
curl_close($ch);
print_r(json_decode($resp, true));

require 'net/http'
require 'json'
require 'uri'

uri = URI('https://api.miniwebtool.com/v1/tools/mortgage-calculator/run')
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = (uri.scheme == 'https')

req = Net::HTTP::Post.new(uri)
req['Authorization'] = 'Bearer mwt_live_YOUR_KEY'
req['Content-Type'] = 'application/json'
req.body = {
  'home_price' => 500000,
  'down_payment' => 100000,
  'annual_rate_percent' => 6.5,
  'years' => 30
}.to_json

resp = http.request(req)
puts JSON.parse(resp.body).inspect

package main

import (
  "bytes"
  "encoding/json"
  "fmt"
  "io"
  "net/http"
)

func main() {
  body, _ := json.Marshal(map[string]interface{}{
    "home_price": 500000,
    "down_payment": 100000,
    "annual_rate_percent": 6.5,
    "years": 30,
  })
  req, _ := http.NewRequest("POST", "https://api.miniwebtool.com/v1/tools/mortgage-calculator/run", bytes.NewReader(body))
  req.Header.Set("Authorization", "Bearer mwt_live_YOUR_KEY")
  req.Header.Set("Content-Type", "application/json")

  resp, err := http.DefaultClient.Do(req)
  if err != nil { panic(err) }
  defer resp.Body.Close()
  out, _ := io.ReadAll(resp.Body)
  fmt.Println(string(out))
}

import java.net.URI;
import java.net.http.*;

var client = HttpClient.newHttpClient();
var req = HttpRequest.newBuilder()
    .uri(URI.create("https://api.miniwebtool.com/v1/tools/mortgage-calculator/run"))
    .header("Authorization", "Bearer mwt_live_YOUR_KEY")
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString("{\"home_price\":500000,\"down_payment\":100000,\"annual_rate_percent\":6.5,\"years\":30}"))
    .build();

var resp = client.send(req, HttpResponse.BodyHandlers.ofString());
System.out.println(resp.body());

Mortgage Calculator

Endpoint

Request body

Cost & access

Response envelope

Try it

Code examples

How to call Mortgage Calculator

Frequently asked

Use from an AI agent

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