# Saylor Innovations Loan Payoff Calculator with Extra Payments

> Saylor Innovations Loan Payoff Calculator with Extra Payments is a paid API for AI agents from saylorinnovations.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-27).

Calculates the impact of making extra monthly payments on a loan — showing monthly payment, months and interest saved, new payoff length, and totals versus the original schedule

## Facts

- Endpoint: GET https://saylorinnovations.com/api/finance/loan-payoff?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/saylor-innovations-loan-payoff-calculator-with-extra-payments-83d0ddfc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__XK5k07bVGI-RxhnDHH8A

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability saylor-innovations-loan-payoff-calculator-with-extra-payments-83d0ddfc
```

Example prompt: If I have a $250,000 mortgage at 6.5% APR over 360 months and I pay an extra $300 each month, how much interest will I save and how many months sooner will I pay it off?

## When to prefer this

Use this endpoint when you need a quick, accurate computation of the financial impact of extra loan payments — covering savings in interest and time — compared to the original amortization schedule. It is ideal for personal finance agents, mortgage advisors, or budgeting tools that want to show users a clear before/after comparison without building their own amortization engine. Prefer this over a full amortization table endpoint when the user only needs summary savings figures rather than a month-by-month breakdown.

## Known failure modes

- Missing required parameters (principal, apr, or term_months) returns an error
- Non-numeric or negative values for principal, APR, or term cause validation errors
- APR of 0% may produce division edge cases or unexpected output
- Very large extra payments that exceed the loan balance may produce unexpected results
- Invalid query parameter formatting (e.g. letters instead of numbers) returns a bad request error

## How this service works

Loan payoff with extra payments - monthly payment, months and interest saved, new payoff length and totals versus the original schedule

## Output

Returns the standard monthly payment, a baseline schedule showing total months, total interest and total paid under the original plan, and a with-extra breakdown showing reduced payoff length, total interest paid, total paid, months saved, interest saved, and years to payoff with the extra payment applied each month.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "principal",
      "apr",
      "term_months"
     ],
     "properties": {
      "apr": {
       "type": "string",
       "description": "Annual rate in percent"
      },
      "principal": {
       "type": "string",
       "description": "Loan amount"
      },
      "term_months": {
       "type": "string",
       "description": "Loan term in months"
      },
      "extra_monthly": {
       "type": "string",
       "description": "optional extra payment each month"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "required": [
      "monthly_payment",
      "baseline",
      "with_extra"
     ],
     "properties": {
      "source": {
       "type": "string",
       "description": "Data source the values come from"
      },
      "baseline": {
       "type": "object",
       "description": "Original schedule: months, total interest and total paid"
      },
      "principal": {
       "type": "number",
       "description": "Starting principal amount"
      },
      "with_extra": {
       "type": "object",
       "description": "With extra"
      },
      "apr_percent": {
       "type": "number",
       "description": "Apr, as a percentage"
      },
      "term_months": {
       "type": "number",
       "description": "Term months"
      },
      "months_saved": {
       "type": "number",
       "description": "Months saved"
      },
      "interest_saved": {
       "type": "number",
       "description": "Interest saved"
      },
      "monthly_payment": {
       "type": "number",
       "description": "Monthly payment amount"
      },
      "payoff_years_with_extra": {
       "type": [
        "number",
        "null"
       ],
       "description": "Payoff years with extra"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/saylor-innovations-loan-payoff-calculator-with-extra-payments-83d0ddfc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from saylorinnovations.com](https://www.zero.xyz/host/saylorinnovations.com/llms.txt)