geproxy is a simple gemini server which accepts gemini urls (as url parameters) to proxy.
eg. gemini://localhost?gemini://gemini.circumlunar.space/docs/specification.gmi will return the response body from gemini://gemini.circumlunar.space/docs/specification.gmi
$ geproxy --help
Usage of ./geproxy:
-cert string
certificate PEM file (default "cert.pem")
-key string
key PEM file (default "key.pem")
-port string
listening port (default "1965")