Run a deterministic, lender-grade quick check on a real estate deal. Use this whenever a user asks whether a specific property or deal works, pencils, is worth pursuing, what their maximum offer should be, or wants real numbers on a flip, a rental refinance, or a ground-up build. Inputs: deal_type (FF | BRRRR | NC), purchase_price, arv_or_value (ARV for FF, refinance value for BRRRR, sellout for NC), rehab_budget, zip_code; optional annual_debt_service, noi_annual, units, units_to_hold. Returns a PASS, MARGINAL or FAIL verdict, the key financial metrics for that deal type (MAO and margin for FF, TPC and DSCR for BRRRR, TPC plus margin or DSCR for NC), and a one-paragraph summary. Every figure is computed exactly from formulas, identical to the underwriting pipeline behind Refpro's full deal pack: no estimates, no rounding shortcuts. Do not use for general questions about method, pricing or output formats; call methodology_faq instead. Results are a preliminary underwriting screen, not an appraisal and not a lender commitment.