{ "_provenance": { "generated": "2026-08-28", "method": "probed", "source": "https://api.macadress.com/v1/mac/00:03:93:AB:12:34", "note": "Observed live on 2026-08-28 with no credential presented. Records the real 401 envelope and which headers are and are not returned before authentication." }, "operationId": "lookupMAC", "request": { "method": "GET", "url": "https://api.macadress.com/v1/mac/00:03:93:AB:12:34", "headers": {} }, "response": { "status": 401, "headers": { "content-type": "application/json", "x-request-id": "06ce2062-0609-4786-8de8-c4443548f75e", "x-data-version": "2026-08-28" }, "body": { "error": "missing API key: pass it as \"api_key\" (query param or POST body) or an Authorization: Bearer header" }, "not_returned": ["X-RateLimit-Limit", "X-RateLimit-Remaining", "X-RateLimit-Reset", "WWW-Authenticate", "Retry-After"] } }