{"query":{"lat":40.015,"lon":-105.27,"altitude_km":0.0,"decimal_year":2026.48219,"input_when":"2026-06-26"},"declination_deg":7.6892,"compass_note":"magnetic north is 7.69 deg east of true north","inclination_deg":66.0322,"horizontal_intensity_nT":20779.63,"north_X_nT":20592.79,"east_Y_nT":2780.29,"down_Z_nT":46742.49,"total_intensity_nT":51153.24,"secular_variation":{"dDeclination_deg_per_yr":-0.0806,"dInclination_deg_per_yr":-0.0498,"dHorizontal_nT_per_yr":-8.9612,"dX_nT_per_yr":-4.9696,"dY_nT_per_yr":-30.1668,"dZ_nT_per_yr":-129.5636,"dTotal_nT_per_yr":-122.0321},"model":"WMM-2025","model_epoch":2025.0,"valid_range":[2025.0,2030.0],"units":{"declination_deg":"degrees, positive east of true north","inclination_deg":"degrees, positive down","intensity":"nanotesla (nT)","secular_variation":"per year"},"deterministic":true,"engine":"WMM2025 spherical-harmonic synthesis (geomag70 algorithm)","demo":true,"demo_inputs":{"lat":40.015,"lon":-105.27,"altitude_km":0.0,"when":"2026-06-26"},"note":"No inputs were given, so this is a worked example on default inputs — the same computation the paid route performs. Pass your own query parameters (see /openapi.json) for a real answer."}