title: How long an attachment link will be available on Facebook Messenger
body: <p>When discussing on Facebook Messenger, you can upload files and send them to the person you're discussing with.  I'm actually developing a Messenger Bot (see <a href="https://developers.facebook.com/docs/messenger-platform" rel="nofollow noreferrer">documentation</a>) and therefore, I'm trying to find the limits of this upload tool.</p>
  
  <p>I found that it's not possible to upload files bigger than 25MB (I put <a href="https://stackoverflow.com/questions/38382639/facebook-messenger-bot-size-of-video-attachment-how-big-can-it-be/41767632#41767632">here</a> how I found this information).</p>
  
  <p>However, I couldn't find for how long these attachments are available once uploaded?  Indeed, Facebook Messenger is uploading the file on server and is sending a link to that resource in the communication.  But I couldn't find if this link will be available forever or if access to it will be limited in time (and therefore, I guess the attachment would be deleted after this duration).</p>