MCP server exposing 2 tools for crtsh.
This URL is a JSON-RPC 2.0 endpoint over HTTP. Issue POST requests with a JSON-RPC body. Browsers and search crawlers land here on GET.
POST https://gateway.pipeworx.io/crtsh/mcp
Content-Type: application/json
{"jsonrpc":"2.0","id":1,"method":"tools/list"}crtsh_search_domain — "Find subdomains of [domain]" / "what TLS certificates exist for [domain]" / "certificate transparency for [host]" / "who issued the cert for [site]" — every certificate ever logged to the public Certificate Transparency logs for a domain and (by default) its subdomains, from crt.sh. AUTHORITATIVE for subdomain discovery and certificate inventory: CAs are required to log every certificate they issue, so this finds hosts that appear in no DNS zone transfer and no web crawl. Returns issuer, validity window, serial number and the full SAN list per certificate, plus a de-duplicated list of every hostname seen. PREFER OVER WEB SEARCH for "what hostnames does this organisation have" and for spotting mis-issued or forgotten certificates.crtsh_certificate — "Show me certificate [crt.sh id]" / "get the PEM for cert [id]" / "which certificate has serial [hex]" — fetch one logged certificate from crt.sh by its crt.sh id or by its hex serial number. Returns the PEM body plus the logged metadata (issuer, common name, SANs, validity window). Use after crtsh_search_domain to pull the actual certificate for inspection, or to identify a certificate you only have a serial number for (e.g. from a CA revocation notice or a TLS error log).Code samples (curl / TypeScript / one-click client install), schemas, and the live playground are on the pack page:
https://pipeworx.io/packs/crtsh/
Pipeworx is an open MCP gateway connecting AI agents to live data. pipeworx.io