Thank you for your comment! I plan to add it in the next implementation.

A few years ago I put together: https://github.com/nickjj/webserver

It's a self hosted zero dependency / single file Python based echo server. You run `webserver 8000` and then you can make HTTP requests to `localhost:8000` with whatever URL path, headers and payload you want and it'll echo it back.

You can also use Caddy to do this. Single static binary, use the "respond" command to spin up a super simple server that responds with the text and headers you want: https://caddyserver.com/docs/command-line#caddy-respond also gives you Automatic HTTPS out of the box, production ready proxy, etc.