index.http

HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
Server: netcat!

<!doctype html>
<html><body><h1>A webpage served by netcat</h1></body></html>

client

#!/bin/bash

# Send a message to the server running on this machine using curl.
curl -X POST --data "Hello, server!" localhost:8080

server

#!/bin/bash

cat index.http | nc -l 8080

curl_jsonplaceholder

#!/bin/bash

curl -X POST \
  --url https://jsonplaceholder.typicode.com/posts \
  --header "Content-Type: application/json" \
  --header "Accept: application/json" \
  --data '{"title": "Welcome!", "body": "Hello and welcome to the blog!"}'