# Amortization Schedule

The row-by-row loan schedule, including the final payment nobody gets right.

**Why delegate it:** A model gets the payment formula roughly right and then drifts: over 360 rows the principal/interest split accumulates rounding error, and the final payment — the one row people actually check against a statement — is almost always wrong. It also cannot reliably answer what an extra $200 a month does to the payoff date. Compounding is a parameter rather than an assumption, because monthly and daily accrual produce genuinely different schedules and the caller knows which loan they have.

Site: https://amortize.gumballtools.com

## Tools

### `amortize_schedule` — Build a loan amortization schedule

Returns the full row-by-row schedule: per-period interest, scheduled principal, any extra principal, PMI, payment and running balance. Handles monthly or daily accrual (daily needs a start date, so leap years follow from the calendar rather than an assumption), biweekly payments, one-off or recurring extra principal, and PMI termination under the Homeowners Protection Act at 78% or 80% of the ORIGINAL value — plus the midpoint trigger that ends PMI regardless of balance. The final payment differs from every other one and is reported as such. Refuses a payment that cannot amortize the balance rather than producing a schedule that never ends. Not financial advice.

Direct endpoint: `https://amortize.gumballtools.com/api/v1/run`

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Via the aggregator: `https://gumballtools.com/api/mcp`
Direct: `https://amortize.gumballtools.com/api/mcp`