Closing Costs & Cash-to-Close Estimator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t4-044

Effect

Computation or source lookup only

Input and validation requirements

An extreme but numerically valid JavaScript input produces 2e308, which overflows to Infinity. The estimator should reject, cap, or otherwise handle non-finite results rather than displaying Infinity as a cash-to-close amount.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "currency": "USD",
    "purchase_price": 400000,
    "down_percent": 20,
    "closing_cost_mode": "percent_of_loan",
    "closing_cost_rate_percent": 3,
    "credits": 2500
  },
  "expected_outputs": {
    "down_payment": 80000,
    "loan_amount": 320000,
    "closing_costs": 9600,
    "credits": 2500,
    "cash_to_close": 87100
  },
  "working": "down_payment = 400000 × 20 ÷ 100 = 80000; loan_amount = 400000 - 80000 = 320000; closing_costs = 320000 × 3 ÷ 100 = 9600; cash_to_close = 80000 + 9600 - 2500 = 87100."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json