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

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

CommunityOnlineNo sign-inGlobalFreeRead-only

What it can do

    What data it sees

    Do you need an account

    No: the server works without sign-in

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

    How to connect

    How to connect MCP Observatory: one read only walk over every https endpoint in the official registry to Claude

    The server address to paste into Claude settings:

    https://observatory.horizonshield.dev/mcp

    1. Open Claude (claude.ai or the desktop app).
    2. Go to Settings → Connectors.
    3. Click Add custom connector.
    4. Paste the server address copied below into Remote MCP server URL and click Add.
    5. In a chat, click + → Connectors and switch the new connector on.

    Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

    Authorization

    After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

    How to connect MCP Observatory: one read only walk over every https endpoint in the official registry to ChatGPT

    The server address to paste into ChatGPT settings:

    https://observatory.horizonshield.dev/mcp

    1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
    2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
    3. Open Settings → Connectors and click Create.
    4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
    5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
    6. In a new chat open + → Apps/Connectors and enable the connector.

    OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

    Authorization

    On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

    How to connect MCP Observatory: one read only walk over every https endpoint in the official registry to Cursor

    The server address to paste into Cursor settings:

    https://observatory.horizonshield.dev/mcp

    Fastest: click Open in Cursor below and confirm the prompt.

    Manually:

    1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
    2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
    3. Save the file. The server appears in the MCP list; authorize it there if asked.

    Authorization

    If the service needs sign-in, an authorize button appears next to the server in the MCP list.

    Server tool list (6)

    Raw names from tools/list. Only developers need these.

    mcp_observatory_stateWhat was measured, when, over what population, and what the measurement cannot tell you. Read this before quoting any number from this server.
    mcp_observatory_summaryThe counts, as published and as corrected. How many addresses answered, how many tools they exposed, how many stated who compensates their operator.
    mcp_observatory_lookupWhat 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.
    mcp_observatory_disclosure_guideHow 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.
    mcp_observatory_measure_nowContact 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.
    mcp_observatory_methodHow the walk was run, what we got wrong and corrected, and the four rules the report holds itself to.