Evidence row 2307528

What was observed

{
  "count": 7,
  "tools": [
    {
      "description": "Paid ($0.01 USDC on Base, x402). Full signed history and current values, verifiable offline. Agent memory: export the full signed history and current values of the paying wallet's persistent key-value store, for backup or proof. The export verifies offline against the public key in /menu, with no trust in the server. The optional since parameter returns only newer entries.. Settles before it runs (a free check refuses a call that would fail). Call once without payment to get the price, then retry with params._meta[\"x402/payment\"].",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "since": {
            "description": "Only entries after this seq",
            "minimum": 0,
            "type": "integer"
          }
        },
        "type": "object"
      },
      "name": "tabularium_export"
    },
    {
      "description": "Free. Free: signed head (seq + hash, no values), state and expiry for a wallet's workspace",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "wallet": {
            "pattern": "^0x[0-9a-fA-F]{40}$",
            "type": "string"
          }
        },
        "required": [
          "wallet"
        ],
        "type": "object"
      },
      "name": "tabularium_head"
    },
    {
      "description": "Free. Prices, payee, network, policy (term, grace, size limits) and the signing key for every call.",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {},
        "type": "object"
      },
      "name": "tabularium_menu"
    },
    {
      "description": "Paid ($0.002 USDC on Base, x402). Latest value for a key, with its chain entry. Agent memory: read the latest value for a key from the paying wallet's persistent key-value store, with its signed hash-chain entry. Reads keep working through the 90-day grace period after the term ends. A missing key returns 404 and is not charged.. Charged only if it succeeds. Call once without payment to get the price, then retry with params._meta[\"x402/payment\"].",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "key": {
            "description": "Key, e.g. notes/today",
            "pattern": "^[A-Za-z0-9._:\\/-]{1,128}$",
            "type": "string"
          }
        },
        "required": [
          "key"
        ],
        "type": "object"
      },
      "name": "tabularium_read"
    },
    {
      "description": "Paid ($0.25 USDC on Base, x402). Extend the workspace by 30 days from the later of now or its expiry. Agent memory: keep the paying wallet's persistent key-value store for 30 more days, counted from the later of now or its current expiry. A free pre-check rejects a wallet with no workspace before any charge.. Settles before it runs (a free check refuses a call that would fail). Call once without payment to get the price, then retry with params._meta[\"x402/payment\"].",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {},
        "type": "object"
      },
      "name": "tabularium_renew"
    },
    {
      "description": "Paid ($0.005 USDC on Base, x402). Fetch a web page as text, with a signed record of what was served and when. Returns the page's readable text plus an Ed25519-signed record (final URL after redirects, fetch time, status, sha256 of the body and of the text) that verifies offline. Charged only for 2xx text pages; refused URLs cost nothing.. Charged only if it succeeds. Call once without payment to get the price, then retry with params._meta[\"x402/payment\"].",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "max_chars": {
            "description": "Most characters of text to return (default 50000); the signature covers exactly what is returned",
            "maximum": 200000,
            "minimum": 1000,
            "type": "integer"
          },
          "url": {
            "description": "Public http(s) page to fetch",
            "maxLength": 2048,
            "pattern": "^https?://",
            "type": "string"
          }
        },
        "required": [
          "url"
        ],
        "type": "object"
      },
      "name": "tabularium_snapshot_fetch"
    },
    {
      "description": "Paid ($0.003 USDC on Base, x402). Append a value under a key in the paying wallet's workspace. Agent memory: save a value under a key in a persistent key-value store owned by the paying wallet. The first write opens a 30-day workspace. Memory survives restarts, new machines and hand-offs between agents. Every write is hash-chained and signed (Ed25519), so the history verifies offline. Values up to 64 KB; failed writes are not charged.. Charged only if it succeeds. Call once without payment to get the price, then retry with params._meta[\"x402/payment\"].",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "idempotency_key": {
            "description": "Optional retry id, kept 7 days",
            "pattern": "^[A-Za-z0-9._:-]{1,128}$",
            "type": "string"
          },
          "key": {
            "description": "Key, e.g. notes/today",
            "pattern": "^[A-Za-z0-9._:\\/-]{1,128}$",
            "type": "string"
          },
          "value": {
            "description": "UTF-8 string; store JSON as a string",
            "maxLength": 65536,
            "type": "string"
          }
        },
        "required": [
          "key",
          "value"
        ],
        "type": "object"
      },
      "name": "tabularium_write"
    }
  ]
}

What the leaf hashes

{"body":"264e99ddc1fc60622e049c2edae6199f14823fb67b1fa5416a1723a2c1614e04","id":2307528,"kind":"mcp.tools","method":"probe.mcp/1","observed_us":1793664995634871,"prev":null,"subject":"de424ed8-2fa7-4d31-b7bb-8f30041e1621","subject_kind":"endpoint"}

Proof

Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of 2026-11-03 (425475 rows).

1. 0xfa5a5a4acfd4ab5079615735a635cfad05c9bc0a47594871c9493faefbf2bf59
2. 0x6b07186b8e43d20cf07e6746469c3075adb04da7cb89a111e4636afbf985b170
3. 0x184b4318e81dcb770a1d74246228f297a01c8928bd64fa36b8c32c0f12e1afc1
4. 0x284f7ff34d11783b76d3b5fc3833aff4173360d160c886cb5c4aa7073641e27c
5. 0x39bbbfa360b5521becaa8571e2df39c1f81d9d202c983ad020a9271f47b76eb1
6. 0x2fd398480c5bc58c0b00c562f4005fd735bd94cfe27c2724cb04fbc3c96c5ed8
7. 0xc12f655b76c94d2b407d4ed921b5aa1c27c6561bccdb1d4722c1843653ad8d17
8. 0x54973009d0042cc8b8b62ecb5c3df309fa7c6b628d092cbd098316827f79a011
9. 0x1b1a18dce491c5dd31b7bdb731fb65da1a45b32105e289c854824b0d836dee71
10. 0x568a7ca3d883b5f9ab12aea40e896745ba1de3ad7025f1d1d52f75966206ae84
11. 0x5347970a2e3cc99ef6cb7802bb643fe1ee6fa23b78417319f72f3e907b734a05
12. 0x423535da8f6395a7fb334eef87c2b331f4a5ce17b0d6ed003ebf18a441197d29
13. 0x4a5043efd66a24ab6ad0989ba3f77d8ad9e29bff006d40f6030cad40e00e02af
14. 0xb67cf31c0f6dfa9976040b7caae9f293217f9d9984435c203bc54a3676e0551b
15. 0xaaf692e701ee622e9e0fa24c7d0f9f672df8c586de5a6f0375f8cadaf0c678a1
16. 0xd60b16e6a71fbffc93a233ee89f916e50c0206a56f52c852b85e5a246b6b417c
17. 0x85f3a27c16056a361d9ba33355a575ca7123f86de901b204c88953c4b8ea441a

Day root

0xb646ffa569e24bf8336b0a15a9d98d0a2f1239f58e10c2b18a9d22e43343566a

Chained

0x35e926359fd19031c6b5e08fb3b44f2524386a57c8fdd353336c185603f53d43

Published

On Arc Testnet, block 70601990: 0xa5f9dadba13cde129126b950e64b815e6833cb8ff53b75026c9dbe769c3768c7