Tool detail
Mortgage & Loan Amortization Cal
Return the monthly payment and full amortization schedule for a fixed-rate loan, with optional extra-payment and lump-sum what-if savings.
Categories: Utilities
Use when
- calculate a mortgage's monthly payment and full payment schedule
- find the interest and time saved from an extra monthly payment or lump sum
Not for
- not variable-rate or adjustable loans -- fixed-rate amortization only
Inputs
POST JSON body: principal, annual_rate_percent, term_months, start_date (all required); extra_monthly_payment, one_time_payments, summary_only, rounding optional.
Inputs undocumented: array without items
Endpoint
- Method
POST- URL
https://mortgage-amortization.underscoredone.com/calculate
Payment
- Protocol
- x402
- Listed price
- 0.01 USDC per call on Base.
- Payment method
- exact
- Network
- eip155:8453
- Asset
- 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Listed terms are catalog metadata. The caller supplies inputs and calls the tool outside Onelayer. If payment is required, the caller uses a compatible wallet to pay.
Source
- Directory
- Coinbase x402 Bazaar
- Record
- POST https://mortgage-amortization.underscoredone.com/calculate
- Retrieved
- 2026-09-30T20:37:07.382Z
- Catalog file SHA-256
6837ccddf886f0007cf3727ea9d27faaa5047b51b4f425345c554ce1c271a524- Catalog built
- 2026-09-30T22:31:58.034Z