{
 "measurement": "x401 (Proof/Notarize) adoption across the x402 catalogue",
 "measured_at": "2026-09-07",
 "catalog_source": "weekly scan 2026-09-06",
 "probed": 15686,
 "x401_emitters": 0,
 "by_generation": {},
 "by_status_top": {
  "402": 10603,
  "404": 1991,
  "405": 1021,
  "unreachable": 917,
  "400": 550,
  "200": 268,
  "401": 89,
  "503": 63,
  "429": 52,
  "410": 37,
  "403": 36,
  "204": 25
 },
 "method": "response-header survey of the full weekly x402 catalogue; both x401 spec generations (v0.1.0 PROOF-REQUIRED/PRESENTATION/RESPONSE and v0.2.0 PROOF-REQUEST/RESPONSE/RESULT), case-insensitive"
}