RealVest Real Estate MCP Server

export class MortgageAffordabilityCalculator { getSchema() { return { type: 'object', properties: { annual_income: { type: 'number', description: 'Annual gross income in dollars', minimum: 0 }, co_borrower_income: { type: 'number', description: 'Co-borrower annual income (default: 0)', default: 0 }, other_monthly_income: { type: 'number', description: 'Other monthly income (rental, investments, etc.)', default: 0 }, car_payment: { type: 'number', description: 'Monthly car loan/lease payments', default: 0 }, student_loans: { type: 'number', description: 'Monthly student loan payments', default: 0 }, credit_cards: { type: 'number', description: 'Monthly credit card minimum payments', default: 0 }, other_debts: { type: 'number', description: 'Other monthly debt payments', default: 0 }, down_payment: { type: 'number', description: 'Down payment amount in dollars', minimum: 0 }, down_payment_percent: { type: 'number', description: 'Down payment percentage (3.5, 5, 10, 15, 20, etc.)', default: 20 }, interest_rate: { type: 'number', description: 'Annual interest rate as a percentage (e.g., 7.0 for 7.0%)', minimum: 0, maximum: 20 }, loan_term: { type: 'number', description: 'Loan term in years (15 or 30)', enum: [15, 30], default: 30 }, property_tax_rate: { type: 'number', description: 'Annual property tax rate as percentage of home value (default: 1.2%)', default: 1.2 }, insurance_annual: { type: 'number', description: 'Annual homeowners insurance cost (default: $1200)', default: 1200 }, hoa_monthly: { type: 'number', description: 'Monthly HOA fees (default: 0)', default: 0 } }, required: ['annual_income', 'down_payment', 'interest_rate'] }; } calculate(params) { const { annual_income, co_borrower_income = 0, other_monthly_income = 0, car_payment = 0, student_loans = 0, credit_cards = 0, other_debts = 0, down_payment, down_payment_percent = 20, interest_rate, loan_term = 30, property_tax_rate = 1.2, insurance_annual = 1200, hoa_monthly = 0 } = params; // Calculate total income and debts const totalAnnualIncome = annual_income + co_borrower_income + (other_monthly_income * 12); const monthlyIncome = totalAnnualIncome / 12; const totalMonthlyDebts = car_payment + student_loans + credit_cards + other_debts; // Calculate maximum monthly housing payment (28% rule) const maxHousingPayment = monthlyIncome * 0.28; // Calculate maximum total debt payment (36% rule) const maxTotalDebt = monthlyIncome * 0.36; const availableForHousing = maxTotalDebt - totalMonthlyDebts; // Use the lower of the two const maxMonthlyPayment = Math.min(maxHousingPayment, availableForHousing); // Calculate other monthly costs const monthlyInsurance = insurance_annual / 12; const monthlyHOA = hoa_monthly; // Estimate property tax (will refine later) const estimatedHomePrice = maxMonthlyPayment * 150; // Rough estimate const monthlyPropertyTax = (estimatedHomePrice * (property_tax_rate / 100)) / 12; // Calculate PMI if down payment < 20% let monthlyPMI = 0; if (down_payment_percent < 20) { monthlyPMI = estimatedHomePrice * 0.005 / 12; // 0.5% annually } // Available for principal and interest const availableForPI = maxMonthlyPayment - monthlyPropertyTax - monthlyInsurance - monthlyPMI - monthlyHOA; // Calculate max loan amount const monthlyRate = interest_rate / 100 / 12; const numPayments = loan_term * 12; const maxLoanAmount = availableForPI * ((1 - Math.pow(1 + monthlyRate, -numPayments)) / monthlyRate); // Calculate max home price based on down payment let maxHomePrice; if (down_payment_percent > 0) { maxHomePrice = maxLoanAmount / (1 - down_payment_percent / 100); } else { maxHomePrice = maxLoanAmount + down_payment; } // Recalculate with actual home price const actualMonthlyTax = (maxHomePrice * (property_tax_rate / 100)) / 12; const actualMonthlyPMI = down_payment_percent < 20 ? (maxHomePrice * 0.005 / 12) : 0; const monthlyPI = availableForPI; const totalMonthlyPayment = monthlyPI + actualMonthlyTax + monthlyInsurance + actualMonthlyPMI + monthlyHOA; // Calculate DTI ratios const frontEndRatio = (totalMonthlyPayment / monthlyIncome) * 100; const backEndRatio = ((totalMonthlyPayment + totalMonthlyDebts) / monthlyIncome) * 100; // Calculate alternative scenarios const conservativePayment = monthlyIncome * 0.25; const moderatePayment = monthlyIncome * 0.28; const aggressivePayment = monthlyIncome * 0.36 - totalMonthlyDebts; // Calculate prices for each scenario const calculatePriceForPayment = (payment) => { const availablePI = payment - actualMonthlyTax - monthlyInsurance - actualMonthlyPMI - monthlyHOA; const loanAmt = availablePI * ((1 - Math.pow(1 + monthlyRate, -numPayments)) / monthlyRate); return down_payment_percent > 0 ? loanAmt / (1 - down_payment_percent / 100) : loanAmt + down_payment; }; return { income_analysis: { monthly_income: Math.round(monthlyIncome), total_annual_income: Math.round(totalAnnualIncome), primary_income: annual_income, co_borrower_income: co_borrower_income, other_monthly_income: other_monthly_income }, debt_analysis: { total_monthly_debts: Math.round(totalMonthlyDebts), car_payment: car_payment, student_loans: student_loans, credit_cards: credit_cards, other_debts: other_debts }, affordability_results: { max_home_price: Math.round(maxHomePrice), max_loan_amount: Math.round(maxLoanAmount), required_down_payment: Math.round(maxHomePrice * (down_payment_percent / 100)), down_payment_percent: down_payment_percent }, monthly_payment_breakdown: { principal_interest: Math.round(monthlyPI), property_tax: Math.round(actualMonthlyTax), insurance: Math.round(monthlyInsurance), pmi: Math.round(actualMonthlyPMI), hoa: monthlyHOA, total_monthly_payment: Math.round(totalMonthlyPayment) }, debt_to_income_ratios: { front_end_ratio: frontEndRatio.toFixed(1) + '%', back_end_ratio: backEndRatio.toFixed(1) + '%', front_end_limit: '28%', back_end_limit: '36%', front_end_status: frontEndRatio <= 28 ? 'Good' : frontEndRatio <= 33 ? 'Caution' : 'Over Limit', back_end_status: backEndRatio <= 36 ? 'Good' : backEndRatio <= 43 ? 'Caution' : 'Over Limit' }, alternative_scenarios: { conservative_25_percent: { max_price: Math.round(calculatePriceForPayment(conservativePayment)), monthly_payment: Math.round(conservativePayment), description: 'Lower risk, more financial flexibility' }, moderate_28_percent: { max_price: Math.round(calculatePriceForPayment(moderatePayment)), monthly_payment: Math.round(moderatePayment), description: 'Standard lending guideline' }, aggressive_36_percent: { max_price: Math.round(calculatePriceForPayment(aggressivePayment)), monthly_payment: Math.round(aggressivePayment), description: 'Maximum typical approval' } }, loan_details: { interest_rate: interest_rate + '%', loan_term: loan_term + ' years', total_payments: numPayments, pmi_required: down_payment_percent < 20, total_interest_paid: Math.round((monthlyPI * numPayments) - maxLoanAmount) }, recommendations: this.generateRecommendations(frontEndRatio, backEndRatio, down_payment_percent, maxHomePrice) }; } generateRecommendations(frontEndRatio, backEndRatio, downPaymentPercent, maxHomePrice) { const recommendations = []; if (frontEndRatio > 28) { recommendations.push("Your housing ratio exceeds 28%. Consider reducing debt or increasing income."); } if (backEndRatio > 36) { recommendations.push("Your total debt ratio exceeds 36%. Pay down existing debts before home shopping."); } if (downPaymentPercent < 20) { recommendations.push("With less than 20% down, you'll pay PMI. Consider saving more to avoid this cost."); } if (maxHomePrice < 200000) { recommendations.push("Consider increasing income, reducing debts, or looking at first-time buyer programs."); } if (frontEndRatio <= 25 && backEndRatio <= 32) { recommendations.push("Great job! Your debt ratios are excellent. You have room for a higher price range if desired."); } return recommendations; } }