title: How do I map an application/json POST request to the params in rails?
body: <p>I am being passed in a json body for a post request, but i'm not sure the best way to map this json body to request params in rails:</p>
  
  <pre><code>{
     username: "example-user",
     password: "password",
     email: "example@gmail.com",
  }
  </code></pre>
  
  <p>and in the controller i wish to acccess params["username"], 
  is this possible? how should i do it?</p>