Evidence row 451343

What was observed

{
  "endpoints": [
    [
      "x402",
      "https://canary.countersignpay.com/v1/base/head"
    ]
  ],
  "name": "canary.countersignpay.com/v1/base/head",
  "owner_address": "0xa0f3c29f25778ddf46fce2cab5f7e7c25e6a1451",
  "raw": {
    "accepts": [
      {
        "amount": "10000",
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "maxTimeoutSeconds": 300,
        "network": "eip155:8453",
        "payTo": "0xa0f3c29f25778dDf46fce2cAB5f7e7C25E6a1451",
        "scheme": "exact"
      }
    ],
    "description": "Current Base mainnet block height and base fee per gas in wei, read from the chain at request time",
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "method": "GET",
            "queryParams": {},
            "type": "http"
          },
          "output": {
            "example": {
              "baseFeePerGas": "1043211",
              "blockHeight": "35812044",
              "network": "eip155:8453",
              "observedAt": "2026-09-15T14:00:00.000Z"
            },
            "type": "json"
          }
        },
        "schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "properties": {
            "input": {
              "additionalProperties": false,
              "properties": {
                "method": {
                  "enum": [
                    "GET"
                  ],
                  "type": "string"
                },
                "queryParams": {
                  "properties": {},
                  "type": "object"
                },
                "type": {
                  "const": "http",
                  "type": "string"
                }
              },
              "required": [
                "type",
                "method"
              ],
              "type": "object"
            },
            "output": {
              "properties": {
                "example": {
                  "properties": {
                    "baseFeePerGas": {
                      "description": "Base fee per gas of that block, in wei, decimal string",
                      "type": "string"
                    },
                    "blockHeight": {
                      "description": "Latest block number on Base mainnet, decimal string",
                      "type": "string"
                    },
                    "network": {
                      "description": "CAIP-2 chain id, always eip155:8453",
                      "type": "string"
                    },
                    "observedAt": {
                      "description": "ISO 8601 time the chain was read",
                      "type": "string"
                    }
                  },
                  "required": [
                    "blockHeight",
                    "baseFeePerGas",
                    "network",
                    "observedAt"
                  ],
                  "type": "object"
                },
                "type": {
                  "type": "string"
                }
              },
              "required": [
                "type"
              ],
              "type": "object"
            }
          },
          "required": [
            "input"
          ],
          "type": "object"
        }
      }
    },
    "lastUpdated": "2026-10-27T10:04:43.7Z",
    "quality": {
      "l30DaysTotalCalls": 13,
      "l30DaysUniquePayers": 7,
      "lastCalledAt": "2026-10-22T21:30:34.111Z"
    },
    "resource": "https://canary.countersignpay.com/v1/base/head",
    "type": "http",
    "x402Version": 2
  },
  "source": "x402_bazaar",
  "summary": "Current Base mainnet block height and base fee per gas in wei, read from the chain at request time"
}

What the leaf hashes

{"body":"3d8ac492be3ba39d24e2aaa057b363bb9af71733afb8970f0141c747d5975d5a","id":451343,"kind":"listing","method":"sync.x402_bazaar/1","observed_us":1793100494732588,"prev":72112,"subject":"x402_bazaar:https://canary.countersignpay.com/v1/base/head","subject_kind":"source_record"}

Proof

Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of 2026-10-27 (273461 rows).

1. 0x54550903ec0fabd3a06aac8ce8aa147da90fc5a464bd8c5227c6d015c509a22d
2. 0x4d6c1352c3d4d3fd20270cf5493be8951e765e9d9ceefc22a3cf70b7aa3deb63
3. 0xaf8ce630c7a95c36942527335e396185b7b740d551e36144059ebf281fbf2b2b
4. 0xb1ce3f927c4bdc2764a8e7ce086e08a1c3d08e28bfeadd6b52a6549782341511
5. 0xbaabee0fb04601c982af10ba25a2ff3adb687d4d72b59747d4dc22bbac879425
6. 0x2f25499c0e0f3d651ec10678a0e33e808401bec4fac9d1b669e258549aaf0056
7. 0x0e4a830e5d269f57b91d0de39203d1aa0fc2a794dacf2d6e1acfe0881a0a1825
8. 0xdfcdbe1ba7813feb50f33779729d2dfa1c5ea5232f69ee362164f004b4c7f112
9. 0x83dd5ce2cac215d14b6396c4ddb78b6390e1e7a63f858ba3bf6c3134b41d3f47
10. 0x7919d7a2c8df293656e34c2d3af4c55ec25ccb6856c4db5cc3788b097d7dd69c
11. 0x64281736f78eb01af3a70566cf7e4fb98158dc598b5edcaf617b2e0560a28c6d
12. 0xf8587b476357dd9dd2bdcf36df59b8f5ada3a7d06a3872295a01a0dd6b9e36d1
13. 0x996f3d89f9508378f3c194c9828b500725dd599c52fd040349190982338d96f2
14. 0x9ea0c6a53f80a30b6f13671109f98a000cf98e581875129f4be4b57131d06364
15. 0xb78ea6a255dd06e2f402a1a733bca392fa6243920bcba95e8b80bdfc6ce5f553
16. 0x3ed50f053eca72dfd3a9d45a11935240bfe691e57835c367ddebe2cbc49efe9d
17. 0x0e01aa9525097570a6edaf32bfc959de57bf5c24317cf10c0716affea85ca60d
18. 0xa20d48798a34aba12eb9c7297722982d910f06c148f5e27ac59307422964a585
19. 0x9fc354c0ea3efc3f1b6548bb77ea902a50f2c9647647ea61592efce2bd795699

Day root

0xdd77e5e99da32c3f154180d63e3c3e6fe11e896a2c6896412ef6b5c4bcf7e795

Chained

0x23bb4dfd09f55c15ac3962f53578e02c6114d5bfd9bb451cf8794fb6e2817ef4

Published

On Arc Testnet, block 69414147: 0xb2ebd83aafeb765a0ce66e76aefb133ed06606c98038fd56191e2bcd1dcb77b4