How to secure callback URLs in Dropbox Sign

You can secure your Dropbox Fax API callback url in two ways:

• Implement Basic Auth
  • This would be something like https://username:password@your.domain/callback
  • Note that basic auth credentials are redacted on Dropbox Fax's side
• Whitelist IPs from Dropbox Fax
  • Ask support@hellosign.com for the outbound IP addresses from Dropbox Fax's API
     

Learn more about callback events.

Learn how to send a fax using the Dropbox Fax API.