MCP Observatory: one read only walk over every https endpoint in the official registry

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Measured conclusion: Deep-tested. L2 outcome: tools_ok.

Public record of one read only walk over the official MCP registry: who answered, tools, who pays.

Author	io.github.ogasurfproject-jpg
Access	remote
Publisher key required	No
Measured state	Deep-tested
L1 liveness	alive
L1 latency	289 ms
Last measured	2026-10-26

Measured statistics

Tools measured	6
Latency, 30-day median (L1)	289 ms
Latency, latest (L1)	289 ms
Safe-call success	1/1 (100%)
30-day success rate (L2)	100%
Last checked	2026-10-26
Total checks	5

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "MCP Observatory: one read only walk over every https endpoint in the official registry": {
      "url": "https://observatory.horizonshield.dev/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (6)

mcp_observatory_state
What was measured, when, over what population, and what the measurement cannot tell you. Read this before quoting any number from this server.
Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared
mcp_observatory_summary
The counts, as published and as corrected. How many addresses answered, how many tools they exposed, how many stated who compensates their operator.
Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared
mcp_observatory_lookup
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.
Parameters:
- host — string — A host, e.g. example.com. Returns counts for that host, not a roster.
- address — string — The full declared endpoint, e.g. https://example.com/mcp
Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared
mcp_observatory_disclosure_guide
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.
Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared
mcp_observatory_measure_now
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.
Parameters:
- address (required) — string — https endpoint, e.g. https://example.com/mcp
Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared
mcp_observatory_method
How the walk was run, what we got wrong and corrected, and the four rules the report holds itself to.
Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

Publisher website Repository

Measured by MCPYP probing. Untested fields are omitted, never estimated. Listing is always free; MCPYP never proxies calls or stores user tokens.