Evidence row 525682

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": 14,
      "l30DaysUniquePayers": 8,
      "lastCalledAt": "2026-10-27T10:04:43.421Z"
    },
    "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":"f307f774c4e43a719d287567932b3ce934e9e47382c793f3512a12462bd8b950","id":525682,"kind":"listing","method":"sync.x402_bazaar/1","observed_us":1793124763780593,"prev":451343,"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. 0x90f50e37c5355b6cb5e52817feab80b487e9e62b382f7cb7ce49296d71907080
2. 0xa33c37f6c58a4c73c1f63e37e73597cec2eb9d367411b52666d1790169e91c7a
3. 0x9f83e3b7277c7121da97ba4980eba0a806bbe19cd5a0dde29b8b187f4d3e9d35
4. 0x8815c29b3cc34e54edc0c5807dd5d41d6603134a83f6a2cd005c3b0ab0c8ef54
5. 0x3117a3a2506acc12f796517c0966b09b7ce9dea418eed2fda17c56b6c7bb1ab3
6. 0x7f79502c14c8423ef13c8c77703f33eedd9560027d92ea2532d87a778bb523b0
7. 0x441603b7611e1aa0531a72f9d958b0c8f97297f6b81a7ef937b3c5eb4b783f23
8. 0xb9d87578605cb783879caa148a8226c4ace2a13783f52b56a88f340c933f52e9
9. 0x8f565cdd57d6208f088fe2949de871ede4952d2764ef9a4ae54a284341e6585d
10. 0xcf1579124a36b994ebce625361a328f39495c357c67b5a9dc898c6b372112fc1
11. 0xe4e0761e46bc22777bc9e4a5791f18fb8244210f2d943234802b8ccdc8d058dc
12. 0xfd2b06953e26e4e360d929209ec04f8c67b7bbdc4861dbc60618fbc5f9b393f0
13. 0x5c9cbca5bb1d6be4d84e301b4e4c1a280536eb16ee98ed4add9057142c132dde
14. 0x06e3b43165f5b3c31d850bc32f20b2e25b844564c4e042c141b9748c26a5a600
15. 0xb4f7223140c8a36cb87a63d77cf617086d9968dc4658f03e102571ebe06e9ed6
16. 0xfecf3d4646dd4984a13dd715499e842c3fde63692336d97394c2bfd8e877ca5d
17. 0xf30fddbf4811226c58e8f0daf36fddd79fc5f1356b592bb1d99a8061ddbabe66
18. 0x2bf8151e5f157dd183b9de6fa00469551932a7a6e3f33a694895000ac9061197
19. 0x9fc354c0ea3efc3f1b6548bb77ea902a50f2c9647647ea61592efce2bd795699

Day root

0xdd77e5e99da32c3f154180d63e3c3e6fe11e896a2c6896412ef6b5c4bcf7e795

Chained

0x23bb4dfd09f55c15ac3962f53578e02c6114d5bfd9bb451cf8794fb6e2817ef4

Published

On Arc Testnet, block 69414147: 0xb2ebd83aafeb765a0ce66e76aefb133ed06606c98038fd56191e2bcd1dcb77b4