title: How to implement Idempotent key into an asp.net web api?
body: <p>An app makes an HTTP post with Idempotency Key in the API request header.</p>
  <p>On the server-side, you want to check if the request with the Idempotent Key has been processed for this client or not.</p>
  <ul>
  <li>If the request has not been processed than we proceed with the method to CREATE, UPDATE  or DELETE.</li>
  <li>If the Idempotent Key has been used in the previous request, then we response back to the client with an error message.</li>
  </ul>
  <p>How do we track the API request, the API count, and the Idempotent Key used in request etc?</p>
  <p>By logging all API request in the database and make a round trip to the database to check this information everytime a new request is made? Or is there a better way?</p>