io.github.Whoisjson/mcp-server
WhoisJSON
WHOIS, DNS, SSL, and domain availability lookups for AI assistants
alive probed 2026-10-15
4tools
757tokens in Claude Opus 5.5
797tokens in Claude Code
0.4 %of a 200k context window
415o200k_base estimate
237 msto initialize
4 msto list tools
- Run it
- npx -y @whoisjson/mcp-server@1.0.3 (stdio, probed in a container with the network off)
- Host
- npmjs.com
- Reports itself as
- @whoisjson/mcp-server 1.0.0
- Capabilities
- tools
- Instructions
- none
- Claude count
- Claude Opus 5.5, measured 2026-10-15. Counted again when the tool definitions change. Method.
- Repository
- https://github.com/Whoisjson/mcp-server
- Registry
- active, updated 2026-04-09 · registry entry
- Reachable
- 1 of the last 1 probe
Most expensive tools
| Tool | Tokens (o200k) | Share of this server |
|---|---|---|
| dns_lookup | 129 | 31 % |
| ssl_check | 108 | 26 % |
| whois_lookup | 97 | 23 % |
| domain_availability | 81 | 20 % |
Badge and feed
[](https://mcpcost.ulehla.dev/s/io.github.Whoisjson/mcp-server)
An entry for every probe that changed the result, the tool count or the token cost: Atom feed. Add it to a feed reader or a Slack RSS app to hear when the server stops answering or its tool set grows.