Outside-in rankings for public MCP servers.
We score public MCP URLs from the outside: reach the server, negotiate the dialect, list tools, complete a call, and record whether the result looked like the job. A is 90 or above. See methodology for the formula.
Updated Oct 21, 2026·83,117 runs·3374 servers·~every 6 hours
How a letter is earned
35%
Reach
Share of probes in 7 days that reached the server. A 200 on the address is the start, not the letter.
30%
Tool success
Did the call complete, and did the result look like the job. Safe reads on the default path.
20%
Speed
Share of scored servers this one beats on P95. Relative to the Index, not a fixed time lid.
15%
Spec
After we negotiate, did transport, discovery, and invocation look like MCP.
2 runs in 7 days to rank. If tool success is missing, the other weights are rescaled. Named hosts scale the mix when we have measured them: untested hosts do not count, and if every measured host fails the score is cut in half. Full formula.
Servers with at least 2 probe runs. A # needs a named-host check. Host-tested sit first.
Index events live on the Index feed.
