Evidence row 2202144

What was observed

{
  "endpoints": [
    [
      "x402",
      "https://calendar-systems.x402tookit.com/leap-year"
    ]
  ],
  "name": "Calendar Systems",
  "owner_address": "0xb531320805c5bed1d46aeadcf4f008fdf172dbda",
  "raw": {
    "accepts": [
      {
        "amount": "20000",
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "maxTimeoutSeconds": 300,
        "network": "eip155:8453",
        "payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
        "scheme": "exact"
      },
      {
        "amount": "20000",
        "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "extra": {
          "feePayer": "D6ZhtNQ5nT9ZnTHUbqXZsTx5MH2rPFiBBggX4hY1WePM",
          "transactionVersions": [
            0
          ]
        },
        "maxTimeoutSeconds": 300,
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
        "scheme": "exact"
      },
      {
        "amount": "20000",
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "maxTimeoutSeconds": 300,
        "network": "eip155:137",
        "payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
        "scheme": "exact"
      },
      {
        "amount": "20000",
        "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "maxTimeoutSeconds": 300,
        "network": "eip155:42161",
        "payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
        "scheme": "exact"
      }
    ],
    "description": "Is a year a leap year in the Gregorian, Julian, Hebrew, Islamic (tabular) or Persian calendar? Rule and nearby leap years.",
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "method": "GET",
            "queryParams": {
              "calendar": "gregorian",
              "year": 1900
            },
            "type": "http"
          },
          "output": {
            "example": {
              "asOf": "2026-10-11T08:54:33.894Z",
              "calendar": "gregorian",
              "daysInYear": 365,
              "degraded": false,
              "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
              "leapCycle": "400 years: 97 leap years",
              "leapYear": false,
              "nextLeapYear": 1904,
              "notChecked": [
                "the Chinese calendar (leap months depend on astronomy and are not covered here)",
                "historical errors: the Julian calendar was misapplied in Rome until about 8 CE",
                "…2 more"
              ],
              "previousLeapYear": 1896,
              "reasons": [
                "Divisible by 4, except century years, which must be divisible by 400 (1900 is not leap, 2000 is).",
                "A common year has no added period."
              ],
              "rule": "Divisible by 4, except century years, which must be divisible by 400 (1900 is not leap, 2000 is).",
              "source": "Published leap rules (Reingold and Dershowitz; Persian by Meeus equinox), computed locally",
              "summary": "1900 is not a leap year in the gregorian calendar (365 days).",
              "verdict": "COMMON_YEAR",
              "year": 1900
            },
            "type": "json"
          }
        },
        "schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "properties": {
            "input": {
              "additionalProperties": false,
              "properties": {
                "method": {
                  "enum": [
                    "GET"
                  ],
                  "type": "string"
                },
                "queryParams": {
                  "properties": {
                    "calendar": {
                      "description": "gregorian (default), julian, hebrew, islamic or persian",
                      "enum": [
                        "gregorian",
                        "julian",
                        "hebrew",
                        "islamic",
                        "persian"
                      ],
                      "type": "string"
                    },
                    "year": {
                      "description": "Year number in the chosen calendar",
                      "type": "integer"
                    }
                  },
                  "required": [
                    "year"
                  ],
                  "type": "object"
                },
                "type": {
                  "const": "http",
                  "type": "string"
                }
              },
              "required": [
                "type",
                "method"
              ],
              "type": "object"
            },
            "output": {
              "properties": {
                "example": {
                  "properties": {
                    "asOf": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "calendar": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "daysInYear": {
                      "type": [
                        "null",
                        "number"
                      ]
                    },
                    "degraded": {
                      "type": [
                        "boolean",
                        "null"
                      ]
                    },
                    "disclaimer": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "leapCycle": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "leapYear": {
                      "type": [
                        "boolean",
                        "null"
                      ]
                    },
                    "nextLeapYear": {
                      "type": [
                        "null",
                        "number"
                      ]
                    },
                    "notChecked": {
                      "items": {
                        "type": "string"
                      },
                      "type": [
                        "array",
                        "null"
                      ]
                    },
                    "previousLeapYear": {
                      "type": [
                        "null",
                        "number"
                      ]
                    },
                    "reasons": {
                      "items": {
                        "type": "string"
                      },
                      "type": [
                        "array",
                        "null"
                      ]
                    },
                    "rule": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "source": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "summary": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "verdict": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "year": {
                      "type": [
                        "null",
                        "number"
                      ]
                    }
                  },
                  "type": "object"
                },
                "type": {
                  "type": "string"
                }
              },
              "required": [
                "type"
              ],
              "type": "object"
            }
          },
          "required": [
            "input"
          ],
          "type": "object"
        }
      }
    },
    "lastUpdated": "2026-11-01T22:40:27.049Z",
    "quality": {
      "l30DaysTotalCalls": 2,
      "l30DaysUniquePayers": 2,
      "lastCalledAt": "2026-11-01T22:40:26.893Z"
    },
    "resource": "https://calendar-systems.x402tookit.com/leap-year",
    "serviceName": "Calendar Systems",
    "tags": [
      "leap-year",
      "calendar",
      "dates"
    ],
    "type": "http",
    "x402Version": 2
  },
  "source": "x402_bazaar",
  "summary": "Is a year a leap year in the Gregorian, Julian, Hebrew, Islamic (tabular) or Persian calendar? Rule and nearby leap years."
}

What the leaf hashes

{"body":"1eb6531249501b418f38bdbb5235399527f6b9b1f22b8a673e64917aec19dc02","id":2202144,"kind":"listing","method":"sync.x402_bazaar/1","observed_us":1793646813484067,"prev":null,"subject":"x402_bazaar:https://calendar-systems.x402tookit.com/leap-year","subject_kind":"source_record"}

Proof

Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of 2026-11-02 (444186 rows).

1. 0xd254429612badfba7011dcc5a65e7d05e4aae310a30d379351a303f490103dc6
2. 0x340e0e9422b1ec43abafa6828f068750f56461e59354f89aeeee9f9f848dca7e
3. 0x6edd3efd370b52a1e0466c7f0447fee10d26a73b708ce5a44af7dc87baf0450b
4. 0x7b9155797abdec0199303c9205035b201018068f985b8b097496c83792d0f276
5. 0xfecb15c00b9e0fe619a17da01254224c1a12b0510d5184062213953bf783583c
6. 0x5e422427a7d756279b882265a3d87a510ff8175b02c2c893f05fee0efbb0d36f
7. 0x5732d4304e126a710c50c2f2d61d7b844d8daad3f4c57d42928318839adecc60
8. 0x71e360f24564887ef3cedbc932d55a9dfe7937c4312c32d7d65cd30336cc64aa
9. 0xe8f58e22f1a197dc7f2eb80fa3d5ffd54c3de8791f94ce78b1a7533095ef3009
10. 0x682faa10845eeb05817001387d51667c15cc99ecedc2a81a3da845319a26def9
11. 0xe2dbc974d9b12796dffe1a22ce6c9cf9b5f24a00a6f898b1bd707086afabbf8d
12. 0x8f7ec337f2782ee71c5fcf875ded67ab29b3a792b4ec497a9bd69388793bc4bb
13. 0x0ee251e21135d18ee3004d16c3618e1f970e8952654b422f2554f8aa0ae09b4f
14. 0x0a363925e7ecbf308dcd4c5e94385984a43aafeb977e419f632e8dc2019e0553
15. 0xa9134f4ed9cec34e13ba243b6a51db73753dbbb3b48c63bd82b22694813d2b02
16. 0x7ddefa7d79e7640c3fed21ee4472689415182c41a0258ab04a81d60495f4c40a
17. 0xdb8bd933619a267f9790faac9839143d202be46af284371cc369cdf683f897ba
18. 0x98cbbf2c68ab4c0b4db782aeb88bea1f30b02178cf8b5d3d24a931d19492ea6d
19. 0x252cce55f1a3d5391c16f82d7f62494429a5f69b03486d4cfcfb7b2c96d6c884

Day root

0x78fecaabbe319e56f5c4b80fc02e2052e198ad24781da8832a475ff65f2002d1

Chained

0xdc35957db5d1371ca382b9152878ffece28ec7c5cb4f98fd71ddb367f8b999b2

Published

On Arc Testnet, block 70432815: 0x56b814612eb2e3e544153df3e91e1f7199106d1e430c7d8c6b653feeb9ebe9af