{"data":{"status":"pass","results":[{"label":"Land's End to John o' Groats","haversineMeters":968876.038,"vincentyMeters":969954.166,"vincentyConverged":true,"vincentyIterations":4,"initialBearingDeg":9.1419,"finalBearingDeg":11.2972,"bearingBasis":"vincenty","haversineMinusVincentyMeters":-1078.129,"claimOk":true}],"engine":"haversine-iugg-r1+vincenty-inverse-wgs84-v1","witnesses":[],"versions":{"engine":"haversine-iugg-r1+vincenty-inverse-wgs84-v1","ellipsoid":"WGS-84 a=6378137 1/f=298.257223563 (EPSG:7030, https://epsg.io/7030-ellipsoid.json, as of 2026-11-04)","meanRadius":"IUGG R1 = (2a+b)/3 = 6371008.7714 m (https://en.wikipedia.org/wiki/Earth_radius, as of 2026-11-04)","vincenty":"Vincenty 1975 inverse, tolerance 1e-12 rad, iteration cap 200","testVectors":"chrisveness/geodesy latlon-ellipsoidal-vincenty-tests.js (as of 2026-11-04)"},"limits":["Ellipsoidal heights are ignored.","Nearly antipodal pairs do not converge in Vincenty and return unknown with the haversine value only."],"deterministic":true},"_provenance":{"version":"writerslogic-provenance/1","issuer":"did:web:agents.writerslogic.com","verify":{"endpoint":"POST /api/v1/verify-provenance","did":"did:web:agents.writerslogic.com"},"manifest":{"format":"application/json","instance_id":"xmp:iid:cf383b2e-45bc-4386-ba65-44745cd9b08c","claim_generator_info":[{"name":"WritersLogic x402 Agent Hub","version":"2.0.0"}],"title":"Great-circle and WGS-84 ellipsoidal distance between coordinates","assertions":[{"label":"c2pa.actions.v2","data":{"actions":[{"action":"c2pa.created","when":"2026-11-06T01:30:32.638Z","softwareAgent":{"name":"writerslogic-agent-hub/geo-distance","version":"2.0.0"},"digitalSourceType":"http://cv.iptc.org/newscodes/digitalsourcetype/algorithmicMedia","parameters":{"endpoint":"POST /api/v1/geo-distance","inputDigest":{"alg":"sha256","hash":"2e2f341d804843ed53f39e5b6cd53156cbbd635673b791c3eec475b7350c79b1","canonicalization":"JCS"}}}]}},{"label":"c2pa.hash.data","data":{"alg":"sha256","hash":"99d756c554b8611e5ca881e00373607f15a30950364a965f9dfedba0abd6b888","name":"jcs-canonical-json(data)"}}]},"credential":{"@context":["https://www.w3.org/ns/credentials/v2"],"id":"urn:uuid:3d31679e-6444-449e-9004-55c200fe9bc0","type":["VerifiableCredential","AgentOutputCredential"],"issuer":"did:web:agents.writerslogic.com","validFrom":"2026-11-06T01:30:32.638Z","credentialSubject":{"id":"urn:sha256:99d756c554b8611e5ca881e00373607f15a30950364a965f9dfedba0abd6b888","agent":"geo-distance","endpoint":"POST /api/v1/geo-distance","outputDigest":{"alg":"sha256","value":"99d756c554b8611e5ca881e00373607f15a30950364a965f9dfedba0abd6b888","canonicalization":"JCS"},"inputDigest":{"alg":"sha256","value":"2e2f341d804843ed53f39e5b6cd53156cbbd635673b791c3eec475b7350c79b1","canonicalization":"JCS"},"manifestDigest":{"alg":"sha256","value":"bd0326de8224bd865a0721488573d3eec508b17a18c98cfde2d092ac6bc019fa","canonicalization":"JCS"},"ingredients":[],"payment":{"scheme":"api-key","network":"eip155:8453","payer":"sample"}},"proof":{"type":"DataIntegrityProof","cryptosuite":"eddsa-jcs-2022","created":"2026-11-06T01:30:32.638Z","verificationMethod":"did:web:agents.writerslogic.com#key-1","proofPurpose":"assertionMethod","proofValue":"z3G5nLQfe1P2GwxySekJSe7Pz9VNSpdseU6TpSUhNp2AUwuVYKWwm5jrNVrMsP9qS46c6HkA7o9qZ5k4zk4id752t"}},"ethSignature":{"type":"EIP-191","signer":"did:pkh:eip155:8453:0x3DBd42560cA7a7E448A2c7DfC9E785526189411f","address":"0x3DBd42560cA7a7E448A2c7DfC9E785526189411f","message":"writerslogic-provenance:79f067d8a05d7a47c328918c6049f26820fb8b114c26721949be1bd564ac2822","signature":"0xdedb60fb7c9a6b483ca89ae90fceb0c2ecf07e69a702f31119998bd01b0a90cb1ef52ff36c27e9188f15baf7fac0f802c1fef553db1f902d939c9e0b3f2e0ecd1c"}}}