The /property-estimate endpoint provides a complete investment projection for a ZIP code — combining market stats, rental data, and standard underwriting assumptions to produce cap rate, monthly cash flow, and cash-on-cash return estimates.

Request

GET /property-estimate?zip_code={zip_code} Parameters: zip_code (string, required) — 5-digit US ZIP code Headers: x-rapidapi-proxy-secret: YOUR_API_KEY

Response Schema

The investment figures are nested under investment_metrics and the model inputs under assumptions — parse those objects, not the top level, for the derived numbers.

{ "zip_code": "78701", "estimated_value": 475000, "value_range_low": 418000, "value_range_high": 532000, "gross_yield_pct": 4.67, "data_source": "redfin_mls", "rent_data_source": "hud_fmr", "investment_metrics": { "monthly_cash_flow": -1418, "cap_rate_pct": 2.8, "cash_on_cash_return_pct": -17.91, "investment_rating": "Negative Cash Flow ⚠️", "down_payment_20pct": 95000, "monthly_mortgage": 2528, "estimated_monthly_rent": 1850 }, "assumptions": { "down_payment_pct": 20, "mortgage_rate_pct": 7.0, "loan_term_years": 30, "expense_ratio_pct": 40, "bedrooms": 2 } }

When a ZIP has too little loaded data to model, the response carries data_source: "unavailable" and a data_note instead of the metrics block — check for investment_metrics before reading it.

How the Worked Example Adds Up

Every figure above is derived from the two inputs — a 78701 median sale price of $475,000 and a 2-bedroom HUD FMR of $1,850/month — using only the stated assumptions:

Net rent = 1850 × (1 − 0.40) = 1110/month Annual NOI = 1110 × 12 = 13320 Cap rate = 13320 / 475000 = 2.8% Loan = 475000 × (1 − 0.20) = 380000 Mortgage = 380000 at 7.0% over 30 years = 2528/month Cash flow = 1110 − 2528 = -1418/month Cash-on-cash = (-1418 × 12) / 95000 = -17.91%

This example is deliberately a negative-cash-flow market: a downtown ZIP with a high median price against a modest 40th-percentile HUD rent. That is what the numbers say, and the endpoint reports it rather than flattering it.

Assumptions Used

ParameterAssumption
Down payment20% of the estimated value
Mortgage rate7.0% fixed, 30-year amortising term
Expense ratio40% of gross rent (vacancy, management, maintenance, insurance, tax)
Bedroom count2-bedroom (HUD BR2 FMR)
Cash-on-cash basisDown payment only — closing costs and capex reserves are excluded

Cash flow is net operating income minus principal and interest; it excludes closing costs, capex reserves and HOA dues. These are standardised assumptions for screening purposes. Your actual results will vary based on purchase price negotiated, financing terms, property-specific expenses, and local management costs. Always verify with a full underwriting model before purchasing.