{"name":"mortgage-payment-calculator","description":"Calculates a full monthly mortgage payment including principal, interest, taxes, insurance, HOA, and PMI. Computes loan amount, principal-and-interest payment, escrow components, total monthly payment, optional housing DTI, score, drivers, and recommendation. Use it as a mortgage payment calculator API, PITI calculator, or home affordability payment estimator.","price":"$0.01","method":"POST","input_schema":{"properties":{"home_price":{"type":"number","description":"Purchase price or property value."},"down_payment":{"type":"number","description":"Cash down payment. Default 0."},"loan_amount":{"type":"number","description":"Optional explicit loan amount; defaults to home_price minus down_payment."},"annual_rate":{"type":"number","description":"Annual mortgage rate as percent, e.g. 6.75."},"term_years":{"type":"number","description":"Loan term in years."},"annual_property_tax":{"type":"number","description":"Annual property tax. Default 0."},"annual_insurance":{"type":"number","description":"Annual homeowners insurance. Default 0."},"monthly_hoa":{"type":"number","description":"Monthly HOA dues. Default 0."},"monthly_pmi":{"type":"number","description":"Monthly PMI. Default 0."},"gross_monthly_income":{"type":"number","description":"Optional borrower gross monthly income for housing DTI."}},"required":["home_price","annual_rate","term_years"]},"input_example":{"home_price":650000,"down_payment":130000,"annual_rate":6.75,"term_years":30,"annual_property_tax":7800,"annual_insurance":1800,"monthly_hoa":125,"gross_monthly_income":16000},"output_example":{"calculator":"mortgage-payment-calculator","score":74.2,"grade":"strong","recommendation":"Proceed with standard diligence and covenant checks.","metrics":{"total_monthly_payment":4568.21,"housing_dti_pct":28.55},"drivers":[{"name":"debt_service_coverage","score":83.6,"weight":0.3,"note":"1.42x DSCR"}],"warnings":[],"source":"deterministic in-process finance calculator; no upstream API"},"x402_payment_required":true,"x402_facilitator":"https://api.cdp.coinbase.com/platform/v2/x402"}