For the complete documentation index, see llms.txt.
Estimate mortgage down payment, loan amount, monthly payment, PMI, and comparison scenarios.
Use this endpoint to add Down Payment Calculator to your app, site, workflow, or agent without rebuilding formulas, validation, examples, and docs.
Prefer the browser version? Open the Down Payment Calculator on miniwebtool.com.
Skip a custom implementation, validation rules, examples, OpenAPI shape, billing checks, and support copy for this utility.
Product forms, calculator pages, finance content, education flows, support tools, automations, and agent actions.
Inspect the required fields, try the hosted playground, then copy cURL, Python, or Node code into your integration.
POST https://api.miniwebtool.com/v1/tools/down-payment-calculator/run
| Field | Type | Req. |
|---|---|---|
home_price
|
float |
✓ |
interest_rate_percent
|
float |
✓ |
down_payment_percent
|
float | None |
— |
down_payment_amount
|
float | None |
— |
loan_term_years
10 | 15 | 20 | 25 | 30
|
str |
— |
property_tax_percent
|
float |
— |
annual_insurance
|
float |
— |
pmi_rate_percent
|
float |
— |
precision
|
int |
— |
hash_only{
"request_id": "01K...",
"tool": "down-payment-calculator",
"tool_version": "2026-04-22",
"credits_used": 2,
"result": { ... }
}
curl -X POST https://api.miniwebtool.com/v1/tools/down-payment-calculator/run \
-H 'Authorization: Bearer mwt_live_YOUR_KEY' \
-H 'Content-Type: application/json' \
-d '{"home_price":350000,"interest_rate_percent":6.5,"down_payment_percent":20,"loan_term_years":"30"}'
import requests
resp = requests.post(
'https://api.miniwebtool.com/v1/tools/down-payment-calculator/run',
headers={'Authorization': 'Bearer mwt_live_YOUR_KEY'},
json={'home_price': 350000, 'interest_rate_percent': 6.5, 'down_payment_percent': 20, 'loan_term_years': '30'},
)
resp.raise_for_status()
print(resp.json())
const resp = await fetch(
'https://api.miniwebtool.com/v1/tools/down-payment-calculator/run',
{
method: 'POST',
headers: {
'Authorization': 'Bearer mwt_live_YOUR_KEY',
'Content-Type': 'application/json',
},
body: JSON.stringify({"home_price":350000,"interest_rate_percent":6.5,"down_payment_percent":20,"loan_term_years":"30"}),
}
);
const data = await resp.json();
console.log(data);
<?php
$ch = curl_init('https://api.miniwebtool.com/v1/tools/down-payment-calculator/run');
curl_setopt_array($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' => 350000,
'interest_rate_percent' => 6.5,
'down_payment_percent' => 20,
'loan_term_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/down-payment-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' => 350000,
'interest_rate_percent' => 6.5,
'down_payment_percent' => 20,
'loan_term_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": 350000,
"interest_rate_percent": 6.5,
"down_payment_percent": 20,
"loan_term_years": "30",
})
req, _ := http.NewRequest("POST", "https://api.miniwebtool.com/v1/tools/down-payment-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/down-payment-calculator/run"))
.header("Authorization", "Bearer mwt_live_YOUR_KEY")
.header("Content-Type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString("{\"home_price\":350000,\"interest_rate_percent\":6.5,\"down_payment_percent\":20,\"loan_term_years\":\"30\"}"))
.build();
var resp = client.send(req, HttpResponse.BodyHandlers.ofString());
System.out.println(resp.body());
home_price, interest_rate_percent, . See the Request body table below for the full schema.
https://api.miniwebtool.com/v1/tools/down-payment-calculator/run
Authorization: Bearer <key> and Content-Type: application/json. Copy-paste snippets in 7 languages are under Code examples.
{request_id, tool, tool_version, credits_used, result}. The typed output lives in result.
Estimate mortgage down payment, loan amount, monthly payment, PMI, and comparison scenarios. Use it to add this utility without rebuilding formulas, validation, examples, and documentation.
2 credits per successful call. Failed calls (validation errors, 5xx) don't bill.
Required fields: home_price, interest_rate_percent. Full schema at /v1/openapi.json.
Yes — same input, same output, forever. Tool version 2026-04-22; output shape is stable within a major version.
Yes. Connect to https://api.miniwebtool.com/v1/mcp over the Model Context Protocol. The agent discovers `down-payment-calculator` with its JSON Schema automatically, so the model can plan while MiniWebtool handles the exact tool result.
JSON with a stable envelope: `{request_id, tool, tool_version, credits_used, result}`. Errors are RFC 7807 `application/problem+json`.
Every endpoint on this site is also exposed via the
Model Context Protocol at
https://api.miniwebtool.com/v1/mcp.
Claude, Cursor, and any MCP-capable agent can discover this tool
(down-payment-calculator)
and its JSON Schema automatically — no client codegen.
# List tools the agent can call
curl -s https://api.miniwebtool.com/v1/mcp \
-H 'Content-Type: application/json' \
-d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' \
| jq '.result.tools[] | select(.name=="down-payment-calculator")'