Evidence row 265127

What was observed

{
  "count": 6,
  "tools": [
    {
      "description": "How the 152 servers that stated who compensates their operator actually did it - the field names observed in the wild, with counts. Not a specification we invented.",
      "inputSchema": {
        "properties": {},
        "type": "object"
      },
      "name": "mcp_observatory_disclosure_guide"
    },
    {
      "description": "What happened when we contacted one address, or an aggregate for one host. Returns the record hash and the procedure to recompute it. There is no tool here that lists addresses; you must already hold the one you are asking about.",
      "inputSchema": {
        "properties": {
          "address": {
            "description": "The full declared endpoint, e.g. https://example.com/mcp",
            "type": "string"
          },
          "host": {
            "description": "A host, e.g. example.com. Returns counts for that host, not a roster.",
            "type": "string"
          }
        },
        "type": "object"
      },
      "name": "mcp_observatory_lookup"
    },
    {
      "description": "Contact one https address now and report what we see: whether it speaks MCP, whether it carries an agent card, and whether that card names who compensates the operator. Read only; no tool is called. robots.txt is read first and honoured. This does NOT change the published record - the next full walk does that. Rate limited, because it contacts somebody else's server on your behalf.",
      "inputSchema": {
        "properties": {
          "address": {
            "description": "https endpoint, e.g. https://example.com/mcp",
            "type": "string"
          }
        },
        "required": [
          "address"
        ],
        "type": "object"
      },
      "name": "mcp_observatory_measure_now"
    },
    {
      "description": "How the walk was run, what we got wrong and corrected, and the four rules the report holds itself to.",
      "inputSchema": {
        "properties": {},
        "type": "object"
      },
      "name": "mcp_observatory_method"
    },
    {
      "description": "What was measured, when, over what population, and what the measurement cannot tell you. Read this before quoting any number from this server.",
      "inputSchema": {
        "properties": {},
        "type": "object"
      },
      "name": "mcp_observatory_state"
    },
    {
      "description": "The counts, as published and as corrected. How many addresses answered, how many tools they exposed, how many stated who compensates their operator.",
      "inputSchema": {
        "properties": {},
        "type": "object"
      },
      "name": "mcp_observatory_summary"
    }
  ]
}

What the leaf hashes

{"body":"54c7110a77fd6e11946c07d032d1a287dc7e8ad573bedcd7b08a8a7ad69887d8","id":265127,"kind":"mcp.tools","method":"probe.mcp/1","observed_us":1793034630817114,"prev":null,"subject":"13936b44-0ca2-46d3-a4e7-5322804e4f0f","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. 0xacfffcbfcb55735927be2d35a3f2c81c7731383223614f36260a483fce983da7
2. 0x1a11d4173405b4bddc3b28cf2a45e686269d443bc0e9a35f0042e92c86cb3775
3. 0xb7fb84e6bf4fc791f5d99a4d6567a9ea6366b8e46e162ee2126f870666258f13
4. 0x08a2c52d76a5262b357c212fc4569b821f300ba2761ab3dda450066c047a55a0
5. 0x848fadbef6faadb23039482ce0ea3f098b3da480886bcd35923ceba4b0bd71d3
6. 0x71faab2c3b0b854630b49e3d79fd81a8c8ed176a4d170f98d0b78762ee64a5f8
7. 0x1c02a2b741bbe5353d3601f509ae48825b406e1285981992e54d01721f087fe3
8. 0x97b55e3b14dfcc3d2146faa1981d79b9b55e21e81c1e3e188fbe625f035edbca
9. 0x7d003e0ec73961fa424e6d95f4fbcef6be41f6598324a2a84740eee0b3f23166
10. 0x69f5e36901c930d3d90499bc3b7d9e7644e48cf4f26d1ebf8d605ee5e9424913
11. 0x317c51a47b234292d19f812377ad1cc4d05ded07987c4ea1ac9ae1ad2b20f0d2
12. 0x51f06c175a7c946ebe50ef243d6f9370a8fe85c996e53eff19ffcc4585ea8c18
13. 0xe292b5a99219f136bce6647ce74b21240a1c7331d2475b1839220fd363c94217
14. 0x3b4dba7d874fc323b0a364140a9c60f37bf547fe671897653118a9873fe03420
15. 0x1a74ed3b3756b9cd946da49701bcec120ec88645013da99fa9eea60b39e1a570
16. 0x123ec8bee20ddc55223eeef5a4f4d6c4b6416515adbb911c56759f5cde56e452
17. 0xd0651cb9bc8155eb52b5247d506e74b8a935057dc190ba52091702ac25ed3a40
18. 0x9a9024edb5069d88a324facb310a5ce8e495214bbaa968f077bede437390194f
19. 0x9b9ce5b74b9bab5121612ef6b64920a8d453cbf311096a423eef9702747e868a

Day root

0xf43e8dcc3d451a4788b26be904c55e8c4c0fa75c9666796c51db38d37e2c0df8

Chained

0x702d5ac508f08b0d1accf36af25822d8e5660367494edd17a642fb61e158a57a

Published

On Arc Testnet, block 69251483: 0x495162f8936e19f0039918feebe6c307f327cd6bf8c37219620b1970041fa9ae