io.github.GautamTalksDev/mcp-pin

mcp-pin

Is the mcp-pin MCP server down? No. It answered initialize and tools/list in the probe of 2026-11-01.

Check if an MCP server's tool definitions changed after approval, from a signed public log.

alive probed 2026-11-14 · unchanged since 2026-11-01

4tools

1.2ktokens in Claude Opus 5.5

0.6 %of Claude's 200k window

0.5×the median server

85 msto initialize

4 msto list tools

Run it: npx -y mcp-pin@0.2.4 (stdio, probed in a container with the network off)
Host: npmjs.com
Reports itself as: mcp-pin-lookup 0.2.4
Capabilities: tools
Instructions: 345 characters
Of a 1M window: 0.1 % of a 1M context window
Count: 1.2k tokens in Claude Opus 5.5, exact, measured 2026-10-16. With the Claude Code prefix mcp__…__ on each tool name: 1.2k. The o200k_base estimate is 759. Counted again when the tool definitions change. Method.
Repository: https://github.com/GautamTalksDev/mcp-pin
Website: https://mcp-pin.gautamkhosla.com
Registry: active, updated 2026-10-31 · registry entry

Most expensive tools

The Claude column scales the o200k estimate of each tool by this server's ratio of exact to estimate, 1.57×.

Tool	≈ Claude tokens	o200k estimate	Share of this server
mcp_pin_server_status	342	217	29 %
mcp_pin_change_summary	327	208	27 %
mcp_pin_how_to_protect	291	185	24 %
mcp_pin_my_servers	235	149	20 %

Other registry entries on npmjs.com, the ones next to this name; all of them.

Servers that mention definitions or approval.

The result of the latest probe, the tool count and the token cost. The feed has an entry for every probe that changed them.

Stops answering, comes back, tool set or cost changes. One confirmation mail first, a stop link in every mail.