I'm looking for something like cURL or httpie, but instead of connecting to an Internet socket and speaking HTTP 1.1 it connects to a Unix socket and speaks FastCGI.
This is for debugging purposes. ncat/socat do not quite cut it because of the nature of the protocol.
I have used the fast-cgi-client and it works fine.
https://github.com/hollodotme/fast-cgi-client
You can also try the pure fcgi-client