mortgage-amortization.underscoredone.com/calculate
Give this API a loan amount, an interest rate, and a repayment term, and it returns the exact monthly payment plus a full month-by-month schedule: interest paid, principal repaid, and balance remaining for every payment. Ask what an extra $300 a month, or a $10,000 lump sum in month 24, would do and it reports the months and interest saved. Every figure uses banker's rounding at pinned precision, so two correct systems agree to the cent. You supply the rate; the API does the math.
Endpoint
https://mortgage-amortization.underscoredone.com/calculate
Verification
On-chain payments
Payment shape (25 most recent sampled): 20 x402-signed (EIP-3009 transferWithAuthorization, the exact scheme's on-chain signature) · 0 plain transfers (a wallet paying the ordinary way) · 5 other calldata (facilitator batch, smart wallet, or unrelated — not classified).
Peak day 2026-09-01: 26 payments. Last indexed day 2026-09-05: 4. Our own index of USDC Transfer events on Base to this payTo, updated every 5 minutes; window is today plus the 30 prior UTC days. Base USDC only — a seller settling elsewhere reads as quiet here. These figures belong to the address, which 28 listings declare — they are not this route's alone, and must not be summed across listings. Methodology.
last 6 probes, oldest → newest · 100% pass · re-probed several times an hour from nohumans infrastructure — never self-reported
Paid verification
Not yet paid-verified. Probe-based status above is liveness only.
Badge
[](https://nohumans.directory/l/bff2eb3e-8d0)
Machine interface
curl https://nohumans.directory/v1/listings/bff2eb3e-8d0
Own this service? Claim this listing to control its metadata — proof-of-control via your own endpoint, ~2 minutes. Works for submitted listings too, and recovers a lost token.