title: How to send transaction from metamask wallet to backend node js
body: <p>i am building simple dapp application where i want to verify something and then only make contract interaction but right now i am struggling to put a middleware which will act like user will make txn through metamask and then this txn or something will go to backend server on any language probably node js , and i will do some checking and if all good then Send it to block chain.</p>
  <p>Any suggestion?</p>
  <p>Right now its all in react Frontend and metamask browser extension.. and i can not make client side code restricted
  And i can not ask for private key even.</p>