{"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)","attestation":{"attested":true,"endpoint":"field","inputs":{"lat":40.015,"lon":-105.27,"altitude_km":0.0,"when":"2026-06-26"},"output_sha256":"62baad33ddf7e176c5972a341e272f6ce9635b3af839fe7a9d9ea7a6f3ec7ff1","authority":{"name":"World Magnetic Model 2025 (WMM2025), US/UK public domain","version":"WMM-2025","engine":"WMM2025 spherical-harmonic synthesis (geomag70 algorithm)","data_file":"WMM2025.COF","data_sha256":"dfa8597825af4e0b87ff4198a5b4fb661b3c49f4cd090cd0164e0259b075582f","matches_published_test_values":"NOAA's published WMM2025 test values to printed precision"},"deterministic":true,"reproduce":"recompute /field with these inputs against World Magnetic Model 2025 (WMM2025), US/UK public domain (WMM2025.COF, sha256 dfa8597825af…); same input -> same bytes; sha256 of the canonical (sorted, attestation-stripped) JSON output must equal output_sha256.","signature":{"signer":"0xA947551dEBB8F0171F16311b1Ce8b5A8f59A8814","scheme":"EIP-191 personal_sign (secp256k1)","statement":"almanac/v1 attests: endpoint=field output_sha256=62baad33ddf7e176c5972a341e272f6ce9635b3af839fe7a9d9ea7a6f3ec7ff1","signature":"0x5920d50dadcd41275939db79663939a3ea3c4bd33071cd1e4d4458f1d39632e4125d976cdc191c0dabb7db18ff58f585210bd60591f0df8a73d944406197448a1b","verify":"EIP-191 recover the signer address from (statement, signature); it must equal `signer`. `signer` is almanac's attestation key — see `endorsed_by` for the earning wallet that authorized it.","endorsed_by":{"earning_wallet":"0xa3091005a76b1480F1897a9D0C2e1c55B7767674","attestation_key":"0xA947551dEBB8F0171F16311b1Ce8b5A8f59A8814","statement":"almanac/v1 endorsement: earning wallet 0xa3091005a76b1480F1897a9D0C2e1c55B7767674 authorizes attestation key 0xA947551dEBB8F0171F16311b1Ce8b5A8f59A8814 to sign deterministic-truth attestations","signature":"0xce89c47280aa480298974acfbcc7b03ee538a24a47e3dc733889261083edcdb01bb3849b2ba892c086c4528f74a37c06df5311dfd2734f232636343f067630621b","scheme":"EIP-191 personal_sign (secp256k1)","verify":"EIP-191 recover the signer from (statement, signature); must equal earning_wallet — the same address that receives x402 payment."}}}}