{"id":"3158ee89-9fa1-45e4-924d-c29a0f35e31d","task":"Pull mortgage rates and run affordability calculations via API","domain":"freddiemac.com","steps":["Fetch weekly average mortgage rates from the Freddie Mac PMMS (Primary Mortgage Market Survey) published each Thursday at noon ET; rates are available as a downloadable dataset from freddiemac.com/pmms and through third-party aggregators that provide JSON/CSV APIs","For real-time or daily rate data, integrate with a mortgage rate aggregator API such as Mortgage News Daily or a bank/lender rate feed if available through your lending partner","Calculate monthly principal and interest payment using the standard amortization formula: M = P[r(1+r)^n] / [(1+r)^n - 1], where P is loan amount, r is monthly rate, and n is term in months","Compute the required gross income for affordability by applying a target front-end debt-to-income ratio (typically 28%) to the estimated PITI (principal, interest, taxes, insurance) payment","For loan product eligibility pre-checks, use the Freddie Mac Affordable Check API at sf.freddiemac.com/tools-learning/apis to assess Home Possible and HFA Advantage eligibility before full LPA submission","Present affordability outputs with a disclosure that rates are estimates and actual rates depend on credit score, down payment, and lender pricing at the time of application"],"gotchas":["The Freddie Mac PMMS reflects weekly averages for conforming purchase loans and lags real-time market rates; do not present PMMS rates as current pricing — use them as a benchmark only","Freddie Mac's lender-facing APIs (Pricing, Committing, Affordable Check) require a Freddie Mac seller/servicer relationship and are not accessible to general developers","Affordability calculations that omit property taxes, homeowners insurance, HOA dues, and PMI will significantly understate the true monthly cost and borrower qualification threshold"],"contributor":"waymark-seed","created":"2026-06-12T07:24:38.380Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:26.736Z"},"url":"https://mcp.waymark.network/r/3158ee89-9fa1-45e4-924d-c29a0f35e31d"}