Evidence row 72306

What was observed

{
  "endpoints": [
    [
      "x402",
      "https://checksum.openverbs.com/v1/fletcher"
    ]
  ],
  "name": "Fletcher-16 / Fletcher-32",
  "owner_address": "0xb3f4de103f34b99f0da19b4f16d6b53a14c2194a",
  "raw": {
    "accepts": [
      {
        "amount": "2000",
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "maxTimeoutSeconds": 300,
        "network": "eip155:8453",
        "payTo": "0xb3f4de103F34b99f0Da19B4F16D6B53a14C2194A",
        "scheme": "exact"
      }
    ],
    "description": "Fletcher checksum over the input payload, in 16-bit (default) or 32-bit width. Returns the checksum as an unsigned integer and hex. Non-cryptographic.",
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "bits": 16,
              "data": "example",
              "encoding": "utf8"
            },
            "bodyType": "json",
            "method": "POST",
            "type": "http"
          }
        },
        "schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "properties": {
            "input": {
              "additionalProperties": false,
              "properties": {
                "body": {
                  "additionalProperties": false,
                  "properties": {
                    "bits": {
                      "description": "Checksum width in bits. Default 16.",
                      "enum": [
                        16,
                        32
                      ],
                      "type": "integer"
                    },
                    "data": {
                      "description": "Input payload.",
                      "maxLength": 5000000,
                      "type": "string"
                    },
                    "encoding": {
                      "description": "How to decode `data`. Default utf8.",
                      "enum": [
                        "utf8",
                        "hex",
                        "base64"
                      ],
                      "type": "string"
                    }
                  },
                  "required": [
                    "data"
                  ],
                  "type": "object"
                },
                "bodyType": {
                  "enum": [
                    "json",
                    "form-data",
                    "text"
                  ],
                  "type": "string"
                },
                "method": {
                  "enum": [
                    "POST"
                  ],
                  "type": "string"
                },
                "type": {
                  "const": "http",
                  "type": "string"
                }
              },
              "required": [
                "type",
                "method",
                "bodyType",
                "body"
              ],
              "type": "object"
            }
          },
          "required": [
            "input"
          ],
          "type": "object"
        }
      }
    },
    "lastUpdated": "2026-10-05T13:26:26.746Z",
    "quality": {
      "l30DaysTotalCalls": 1,
      "l30DaysUniquePayers": 1,
      "lastCalledAt": "2026-10-05T13:26:26.48Z"
    },
    "resource": "https://checksum.openverbs.com/v1/fletcher",
    "serviceName": "Fletcher-16 / Fletcher-32",
    "tags": [
      "fletcher checksum",
      "fletcher16 checksum",
      "fletcher32 checksum",
      "calculate fletcher",
      "fletcher api"
    ],
    "type": "http",
    "x402Version": 2
  },
  "source": "x402_bazaar",
  "summary": "Fletcher checksum over the input payload, in 16-bit (default) or 32-bit width. Returns the checksum as an unsigned integer and hex. Non-cryptographic."
}

What the leaf hashes

{"body":"97b1337178adddc2045eaee56fa60553439c31ddc9832780f900d3b15bbd0a01","id":72306,"kind":"listing","method":"baseline/1","observed_us":1793025485616743,"prev":null,"subject":"x402_bazaar:https://checksum.openverbs.com/v1/fletcher","subject_kind":"source_record"}

Proof

Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of 2026-10-26 (296695 rows).

1. 0xac7b873173f7bed538e67c0f1712d755c4ae937159f20003b856f7cb2c76375b
2. 0x4262c9d205e08d9b4d7e0ac5050bd4315e1f7bc58f91cf19ee2548d56b33804c
3. 0xb631baab90675c238a77133beb62c4746840f59f2a9f097e0291df6800d6834e
4. 0xe8cc4dce16daf1f886f2c62f041a4bd9c19e8b8906f64571e55880c07afe24dd
5. 0xf6b002a5731eb61421b8706297e5f70657b4ca017db2151a8d74a5a14392e98a
6. 0x909c60bb2d53bc623def6498678470b63315ae3c83d2c80d729493f1a96ee00d
7. 0xa7276cf2de8d13ed7cafa12c516e42c61e83f8b0923369e51d7dcad44bf54c9e
8. 0xdcf751e1326fa9d7a3d180688a02bbffe81d87be6331ab06f33f5e90ce299f9a
9. 0xb534cbe0be78469c8f0a3d0670c9d16c3638abf08efcaab7785e2519e34b3eda
10. 0xc97abdede7c4060ef185e84128116a0ad0ab1d598f63d28fa5df0730f940fb58
11. 0x3777e64f7ac9f40ae7e4f13404a570afc2a739656a377469485865c026d1c99c
12. 0xb7fae69bb7bd717d54a83df961404a3e4de2a5cfbcfa013fd83a38627fe13f7e
13. 0x4700d6dfdb40e52e2ceb8ffe62c75f3f708d23452f828255fd003d795f5d9d66
14. 0x3b4dba7d874fc323b0a364140a9c60f37bf547fe671897653118a9873fe03420
15. 0x1a74ed3b3756b9cd946da49701bcec120ec88645013da99fa9eea60b39e1a570
16. 0x123ec8bee20ddc55223eeef5a4f4d6c4b6416515adbb911c56759f5cde56e452
17. 0xd0651cb9bc8155eb52b5247d506e74b8a935057dc190ba52091702ac25ed3a40
18. 0x9a9024edb5069d88a324facb310a5ce8e495214bbaa968f077bede437390194f
19. 0x9b9ce5b74b9bab5121612ef6b64920a8d453cbf311096a423eef9702747e868a

Day root

0xf43e8dcc3d451a4788b26be904c55e8c4c0fa75c9666796c51db38d37e2c0df8

Chained

0x702d5ac508f08b0d1accf36af25822d8e5660367494edd17a642fb61e158a57a

Published

On Arc Testnet, block 69251483: 0x495162f8936e19f0039918feebe6c307f327cd6bf8c37219620b1970041fa9ae