We have released support in the Box Sign API for
- Webhooks to enable custom applications to listen to specific Sign events to trigger other actions
 - Redirect flows to custom landing pages on completion of signers actions like signing and declining to sign
 
For more info, please refer the the documentation below:
Webhooks
- https://developer.box.com/guides/box-sign/#webhooks
 - https://developer.box.com/guides/webhooks/triggers/#sign-request
 - https://developer.box.com/reference/resources/webhook-invocation/#param-trigger
 
Redirect flows
- https://developer.box.com/reference/post-sign-requests/
 - https://developer.box.com/guides/box-sign/create-sign-request/
 - https://developer.box.com/changelog/#2022-06-24-new-redirect-url-parameters