Evidence row 291573

What was observed

{
  "count": 4,
  "tools": [
    {
      "description": "The current .ots proof of one stamp, base64. Once get_stamp says complete, fetch it again: the complete proof carries the Bitcoin attestation and can be verified by anyone, without us. Save it next to the file as <file>.ots. Free.",
      "inputSchema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "id": {
            "description": "The stamp id (stp_…), as returned by stamp_hashes",
            "minLength": 1,
            "type": "string"
          }
        },
        "required": [
          "id"
        ],
        "type": "object"
      },
      "name": "get_proof"
    },
    {
      "description": "Status of one stamp: pending, complete (with the Bitcoin block height and time, and a statement of what it proves) or failed (not confirmed within 7 days). Free.",
      "inputSchema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "id": {
            "description": "The stamp id (stp_…), as returned by stamp_hashes",
            "minLength": 1,
            "type": "string"
          }
        },
        "required": [
          "id"
        ],
        "type": "object"
      },
      "name": "get_stamp"
    },
    {
      "description": "Timestamp 1-100 SHA-256 hashes in Bitcoin. Paid per hash with x402: without a payment the tool returns an error whose structuredContent is an x402 PaymentRequired (x402Version 2, exact scheme, USDC on Base). Retry with the same arguments and the signed PaymentPayload in the request's _meta[\"x402/payment\"] (the x402 MCP transport), or, if your client cannot set _meta, in the `payment` argument. The settlement comes back in _meta[\"x402/payment-response\"]. Returns a batch with, per hash, the stamp id, a pending .ots proof (base64: save it now) and its ots_url, plus a receipt signed by us. Invalid input is never charged; retrying with the same payment and arguments returns the same answer without paying twice.",
      "inputSchema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "hashes": {
            "description": "1-100 SHA-256 hashes, each only once (sha256sum file.pdf, shasum -a 256 file.pdf)",
            "items": {
              "description": "SHA-256 of the file, 64 hex characters",
              "type": "string"
            },
            "type": "array"
          },
          "payment": {
            "anyOf": [
              {
                "type": "string"
              },
              {
                "additionalProperties": {},
                "propertyNames": {
                  "type": "string"
                },
                "type": "object"
              }
            ],
            "description": "Only if your client cannot send _meta[\"x402/payment\"]: the x402 PaymentPayload, as an object or base64"
          },
          "webhook": {
            "description": "Optional webhook; deliveries are always signed with our Ed25519 key (see https://stampthisfile.com/llms.txt)",
            "properties": {
              "signing_key": {
                "description": "Optional whsec_<base64> for a Standard Webhooks HMAC (v1) signature",
                "type": "string"
              },
              "url": {
                "description": "Public https URL that gets one POST when the batch completes or fails",
                "type": "string"
              }
            },
            "required": [
              "url"
            ],
            "type": "object"
          }
        },
        "required": [
          "hashes"
        ],
        "type": "object"
      },
      "name": "stamp_hashes"
    },
    {
      "description": "Check an OpenTimestamps proof (from us or anyone) against the SHA-256 of a file. Returns valid with status complete (Bitcoin block and the time the file existed by), valid with status pending (not in Bitcoin yet), or invalid with a reason. A pending proof whose calendars have since committed it comes back complete with `upgraded: true` and the completed proof in `ots` (base64): save it in place of the pending one. Nothing is stored. Free.",
      "inputSchema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "hash": {
            "description": "SHA-256 of the file, 64 hex characters",
            "type": "string"
          },
          "ots": {
            "description": "The .ots proof, base64",
            "type": "string"
          }
        },
        "required": [
          "hash",
          "ots"
        ],
        "type": "object"
      },
      "name": "verify_proof"
    }
  ]
}

What the leaf hashes

{"body":"f4a1349d2726b4f5dbd099027bac76151683884848cdd6df9573b5de2fd81146","id":291573,"kind":"mcp.tools","method":"probe.mcp/1","observed_us":1793048173228835,"prev":null,"subject":"b9150897-8a9a-4bd0-97ee-378b6501d817","subject_kind":"endpoint"}

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. 0xf87e1d5d334e6886ae53868a8d535dd88ef5181b82b25e586ed9bfeef2c2b7db
2. 0xd685beb50a48ba5e1b793c774d64976434694577e912959f208cae8b3e02e37f
3. 0xd02057dd01402ecc7d9e019f1f21cc1d000b1553649ab5bf2ac104920759c9b3
4. 0xd3abf8ac9a5cc92b4acfd645b547f2cd307c2205b5ca6a3edd5b660c19884800
5. 0x202917599f00afa29e5c2c4282225f8c9baa0f6206a590056de4a50fd607511e
6. 0xb7a08a1fcc540d0c5d943affb51b7ed9a390fc536a7359cbdee66c1fff78b943
7. 0x3bb86c0efab6b6fd6946b2a3e2c0bb8db8e8e837da3f6aab2e030fa04f4079dc
8. 0x5f885a026b10d7405bc704cb4bfe296049a874f07c38fd50a9a9cec2a0d84f00
9. 0x60c913cb9f6ab365a73091fed8c4efa74ad0caddec29ccd05cb049370255c742
10. 0xedbb756c6884e1e4b4d8aa27e3c5a9118300a1c763d183c08ab09c58ee11482f
11. 0xe3be477672f672ad65922159dceef6444408759f2808a7a1e1ba87146cf5eee0
12. 0xf7eba200f6f1012d700fcc53fc6d57dcafd1019c920b1030d42fa21d4af95d94
13. 0x694eb701ea36a0e3dcde192253ab85a618738bdc1e3a6e582e6f8bf9647f7a6a
14. 0x44945ea9ad8b24e723ad5a8fd6d014024a49531783f74ff9229c2ab6930e84c8
15. 0x68d296b1e00b4899fb83c3fba36fffaefa311eac2903067dbebfe776a12b4a9a
16. 0x5fb5dda563336cd1bc1b9f44c52b76237ae72ed2145cb9290f39f304ca7dd678
17. 0x74a0a08e4e7ab9aa5bfbead33dec7e1c7e8e364cff69a63720d764bbe987aadc

Day root

0xf43e8dcc3d451a4788b26be904c55e8c4c0fa75c9666796c51db38d37e2c0df8

Chained

0x702d5ac508f08b0d1accf36af25822d8e5660367494edd17a642fb61e158a57a

Published

On Arc Testnet, block 69251483: 0x495162f8936e19f0039918feebe6c307f327cd6bf8c37219620b1970041fa9ae