What does the Biweekly Mortgage Payment Calculator API do?

Biweekly versus monthly mortgage payments with interest saved and time cut from the term. Use it to add this utility without rebuilding formulas, validation, examples, and documentation.

How much does one call to Biweekly Mortgage Payment Calculator cost?

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

What parameters does the Biweekly Mortgage Payment Calculator API require?

Required fields: (none). Full schema at /v1/openapi.json.

Is the Biweekly Mortgage Payment Calculator API deterministic?

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

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`.

Biweekly Mortgage Payment Calculator API

Field	Type	Req.
`loan_amount` loan principal	`float`	—
`interest_rate` annual interest rate %	`float`	—
`loan_term` 30 \| 8 \| 10 \| 12 \| 15 \| 20 \| 25 \| 40	`str`	—

Field

Type

Req.

loan_amount

loan principal

float

—

interest_rate

annual interest rate %

float

—

loan_term

30 | 8 | 10 | 12 | 15 | 20 | 25 | 40

str

—

curl -X POST https://api.miniwebtool.com/v1/tools/biweekly-mortgage-payment-calculator/run \ -H 'Authorization: Bearer mwt_live_YOUR_KEY' \ -H 'Content-Type: application/json' \ -d '{"loan_amount":300000,"interest_rate":6.5,"loan_term":"30"}'

import requests resp = requests.post( 'https://api.miniwebtool.com/v1/tools/biweekly-mortgage-payment-calculator/run', headers={'Authorization': 'Bearer mwt_live_YOUR_KEY'}, json={'loan_amount': 300000, 'interest_rate': 6.5, 'loan_term': '30'}, ) resp.raise_for_status() data = resp.json() print(data)

<?php $ch = curl_init('https://api.miniwebtool.com/v1/tools/biweekly-mortgage-payment-calculator/run'); curl_setopt_array($ch, [ CURLOPT_POST => true, CURLOPT_RETURNTRANSFER => true, CURLOPT_HTTPHEADER => [ 'Authorization: Bearer mwt_live_YOUR_KEY', 'Content-Type: application/json', ], CURLOPT_POSTFIELDS => json_encode([ 'loan_amount' => 300000, 'interest_rate' => 6.5, 'loan_term' => '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/biweekly-mortgage-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 = { 'loan_amount' => 300000, 'interest_rate' => 6.5, 'loan_term' => '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{}{ "loan_amount": 300000, "interest_rate": 6.5, "loan_term": "30", }) req, _ := http.NewRequest("POST", "https://api.miniwebtool.com/v1/tools/biweekly-mortgage-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/biweekly-mortgage-payment-calculator/run")) .header("Authorization", "Bearer mwt_live_YOUR_KEY") .header("Content-Type", "application/json") .POST(HttpRequest.BodyPublishers.ofString("{\"loan_amount\":300000,\"interest_rate\":6.5,\"loan_term\":\"30\"}")) .build(); var resp = client.send(req, HttpResponse.BodyHandlers.ofString()); System.out.println(resp.body());

Integrate the MiniWebtool Biweekly Mortgage Payment Calculator API into this project. ## Your task 1. Read the reference below. 2. Ask me where this belongs in the codebase if it is not obvious. 3. Write the integration in the language and style of the surrounding code: a small typed client function, errors handled, key read from the environment (never hard-coded, never committed). 4. Verify with `/dry-run` first, then exactly one live call. 5. Show me the diff and the live result. ## Credit budget — follow these exactly This API is metered. A live call costs 2 credits; the free tier includes 1,000 credits per month. Burning them during integration is the single most common way to waste this key. 1. **Do all wiring against `/dry-run`, which costs 0 credits.** It validates the payload for real and returns a sample result with the exact response shape. Iterate there until your request builds and your parsing works. 2. **Make at most ONE live `/run` call** — a single end-to-end confirmation once dry-run passes. Print the result, then stop. 3. **Never call the API from unit tests, examples, or a retry loop.** Assert against the sample response captured from `/dry-run` instead. 4. **On 4xx, fix the payload — do not retry.** The error body is RFC 7807 `application/problem+json` and says exactly what is wrong. 5. **On 429, honour `Retry-After`** and back off; do not tighten the loop. 6. **Read `X-MWT-Credits-Remaining`** on every response. If it drops below 50, stop making live calls and tell me. 7. If the integration needs repeated calls at runtime, **cache by input** — this tool is deterministic, so the same input always returns the same output. ## The API **Biweekly Mortgage Payment Calculator** — Biweekly versus monthly mortgage payments with interest saved and time cut from the term. - Live endpoint: `POST https://api.miniwebtool.com/v1/tools/biweekly-mortgage-payment-calculator/run` — costs 2 credits - Dry run: `POST https://api.miniwebtool.com/v1/tools/biweekly-mortgage-payment-calculator/dry-run` — costs 0 credits, same auth and validation - Auth: `Authorization: Bearer <MINIWEBTOOL_API_KEY>` - Content type: `application/json` - Tool version: `2026-04-22` (output shape is stable within a major version) - Full machine-readable spec: `https://api.miniwebtool.com/v1/openapi.json` ### Request body | field | type | required | notes | |---|---|---|---| | `loan_amount` | float | no | loan principal (default `300000`) | | `interest_rate` | float | no | annual interest rate % (default `6.5`) | | `loan_term` | str | no | one of: 30, 8, 10, 12, 15, 20, 25, 40 — 30 \| 8 \| 10 \| 12 \| 15 \| 20 \| 25 \| 40 (default `30`) | Example request body: ```json { "loan_amount": 300000, "interest_rate": 6.5, "loan_term": "30" } ``` ### Response envelope ```json { "request_id": "req_01H…", "tool": "biweekly-mortgage-payment-calculator", "tool_version": "2026-04-22", "credits_used": 2, "result": { "loan_amount": 300000.0, "interest_rate_pct": 6.5, "loan_term_years": 30, "monthly_payment": 1896.2, "biweekly_payment": 948.1, "payments_per_year": 26, "equivalent_monthly_payments_per_year": 13, "extra_paid_per_year": 1896.2, "monthly_total_interest": 382633.47, "biweekly_total_interest": 294511.68, "interest_saved": 88121.78, "biweekly_payoff_periods": 628, "biweekly_payoff_years": 24.15, "time_saved_months": 70, "time_saved": "5 years 10 months", "note": "26 biweekly half-payments equal 13 monthly payments a year." } } ``` `result` holds the tool output. Errors come back as `application/problem+json` with `type`, `title`, `status`, and `detail`. ### Getting a key If `MINIWEBTOOL_API_KEY` is not already in the environment, stop and ask me for one — do not sign up, scrape, or guess a key. Free keys: https://api.miniwebtool.com/dashboard/

--- description: MiniWebtool Biweekly Mortgage Payment Calculator API — usage and credit budget globs: alwaysApply: false --- # MiniWebtool Biweekly Mortgage Payment Calculator API ## The API **Biweekly Mortgage Payment Calculator** — Biweekly versus monthly mortgage payments with interest saved and time cut from the term. - Live endpoint: `POST https://api.miniwebtool.com/v1/tools/biweekly-mortgage-payment-calculator/run` — costs 2 credits - Dry run: `POST https://api.miniwebtool.com/v1/tools/biweekly-mortgage-payment-calculator/dry-run` — costs 0 credits, same auth and validation - Auth: `Authorization: Bearer <MINIWEBTOOL_API_KEY>` - Content type: `application/json` - Tool version: `2026-04-22` (output shape is stable within a major version) - Full machine-readable spec: `https://api.miniwebtool.com/v1/openapi.json` ### Request body | field | type | required | notes | |---|---|---|---| | `loan_amount` | float | no | loan principal (default `300000`) | | `interest_rate` | float | no | annual interest rate % (default `6.5`) | | `loan_term` | str | no | one of: 30, 8, 10, 12, 15, 20, 25, 40 — 30 \| 8 \| 10 \| 12 \| 15 \| 20 \| 25 \| 40 (default `30`) | Example request body: ```json { "loan_amount": 300000, "interest_rate": 6.5, "loan_term": "30" } ``` ### Response envelope ```json { "request_id": "req_01H…", "tool": "biweekly-mortgage-payment-calculator", "tool_version": "2026-04-22", "credits_used": 2, "result": { "loan_amount": 300000.0, "interest_rate_pct": 6.5, "loan_term_years": 30, "monthly_payment": 1896.2, "biweekly_payment": 948.1, "payments_per_year": 26, "equivalent_monthly_payments_per_year": 13, "extra_paid_per_year": 1896.2, "monthly_total_interest": 382633.47, "biweekly_total_interest": 294511.68, "interest_saved": 88121.78, "biweekly_payoff_periods": 628, "biweekly_payoff_years": 24.15, "time_saved_months": 70, "time_saved": "5 years 10 months", "note": "26 biweekly half-payments equal 13 monthly payments a year." } } ``` `result` holds the tool output. Errors come back as `application/problem+json` with `type`, `title`, `status`, and `detail`. ### Getting a key If `MINIWEBTOOL_API_KEY` is not already in the environment, stop and ask me for one — do not sign up, scrape, or guess a key. Free keys: https://api.miniwebtool.com/dashboard/ ## Credit budget — follow these exactly This API is metered. A live call costs 2 credits; the free tier includes 1,000 credits per month. Burning them during integration is the single most common way to waste this key. 1. **Do all wiring against `/dry-run`, which costs 0 credits.** It validates the payload for real and returns a sample result with the exact response shape. Iterate there until your request builds and your parsing works. 2. **Make at most ONE live `/run` call** — a single end-to-end confirmation once dry-run passes. Print the result, then stop. 3. **Never call the API from unit tests, examples, or a retry loop.** Assert against the sample response captured from `/dry-run` instead. 4. **On 4xx, fix the payload — do not retry.** The error body is RFC 7807 `application/problem+json` and says exactly what is wrong. 5. **On 429, honour `Retry-After`** and back off; do not tighten the loop. 6. **Read `X-MWT-Credits-Remaining`** on every response. If it drops below 50, stop making live calls and tell me. 7. If the integration needs repeated calls at runtime, **cache by input** — this tool is deterministic, so the same input always returns the same output.

Add the MiniWebtool MCP server to this project, then use the `biweekly-mortgage-payment-calculator` tool from it. Server URL: https://api.miniwebtool.com/v1/mcp Transport: HTTP (Streamable HTTP / JSON-RPC 2.0) Auth header: `Authorization: Bearer <MINIWEBTOOL_API_KEY>` Claude Code: ```bash claude mcp add --transport http miniwebtool https://api.miniwebtool.com/v1/mcp \ --header "Authorization: Bearer $MINIWEBTOOL_API_KEY" ``` Or add it to the MCP config file your client uses: ```json { "mcpServers": { "miniwebtool": { "type": "http", "url": "https://api.miniwebtool.com/v1/mcp", "headers": { "Authorization": "Bearer ${MINIWEBTOOL_API_KEY}" } } } } ``` Once connected, `tools/list` exposes `biweekly-mortgage-payment-calculator` with its JSON Schema, so you can call it directly instead of writing an HTTP client. ## Credit budget — follow these exactly This API is metered. A live call costs 2 credits; the free tier includes 1,000 credits per month. Burning them during integration is the single most common way to waste this key. 1. **Do all wiring against `/dry-run`, which costs 0 credits.** It validates the payload for real and returns a sample result with the exact response shape. Iterate there until your request builds and your parsing works. 2. **Make at most ONE live `/run` call** — a single end-to-end confirmation once dry-run passes. Print the result, then stop. 3. **Never call the API from unit tests, examples, or a retry loop.** Assert against the sample response captured from `/dry-run` instead. 4. **On 4xx, fix the payload — do not retry.** The error body is RFC 7807 `application/problem+json` and says exactly what is wrong. 5. **On 429, honour `Retry-After`** and back off; do not tighten the loop. 6. **Read `X-MWT-Credits-Remaining`** on every response. If it drops below 50, stop making live calls and tell me. 7. If the integration needs repeated calls at runtime, **cache by input** — this tool is deterministic, so the same input always returns the same output.

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 (biweekly-mortgage-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=="biweekly-mortgage-payment-calculator")'

Biweekly Mortgage Payment Calculator API

Endpoint

Request body

Cost & access

Response envelope

Try it

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Code examples