title: Duplicate Pinterest Facebook invite functionality
body: <p>I'm trying to duplicate Pinterest's "Invite Friends" functionality. In case you haven't seen what it looks like, it looks like this:
  <img src="https://i.stack.imgur.com/0OSfF.png" alt="enter image description here"></p>
  
  <p>This important points here are 1) there are multiple recipients and 2) you can type a custom message.</p>
  
  <p>So far, with the Facebook API, I've only found ways to send a custom message to a single user or send a pre-canned message to multiple users. I haven't found a way to send a custom message to multiple users.</p>
  
  <p>Here's what will let you send a custom message to just one user: <a href="https://developers.facebook.com/docs/reference/dialogs/send/" rel="noreferrer">https://developers.facebook.com/docs/reference/dialogs/send/</a></p>
  
  <p>And here's what will let you send a pre-canned message to multiple users:
  <a href="https://developers.facebook.com/docs/reference/dialogs/requests/" rel="noreferrer">https://developers.facebook.com/docs/reference/dialogs/requests/</a></p>
  
  <p>So how are they doing it? How can I allow my user to send a custom message to multiple recipients like Pinterest is doing?</p>