{"model":"arm-vs-fixed","specVersion":"1.0.0","specUrl":"/api/v1/models/arm-vs-fixed/spec","inputs":{"loanAmount":{"kind":"float","min":10000,"max":2000000},"termMonths":{"kind":"int","min":120,"max":480},"fixedRate":{"kind":"float","min":0.005,"max":0.15},"armInitialRate":{"kind":"float","min":0.001,"max":0.15},"armInitialPeriodMonths":{"kind":"int","min":12,"max":120},"armAdjustedRate":{"kind":"float","min":0.005,"max":0.2}},"arrayInputs":{},"constraints":["armInitialPeriodMonths must be ≤ termMonths − 12 (the adjustment happens at least a year before payoff); violating requests are rejected, never adjusted."],"sentinels":[],"facts":[],"disclaimer":"Illustrative planning model, not financial advice. Outputs follow the published model spec exactly; read the spec for assumptions and exclusions before relying on any number."}