Context.IO offers 2 webhook options: setting webhooks at the user level, or at the application level.
When to use user level webhooks
If you are using a unique identifier for callback urls, or if you are monitoring specific folders or senders that are specific to the user only, you should select user level webhooks.
A user-level webhook creates a webhook rule that only applies to the user, and therefore can be user-specific.
When to use application level webhooks
If all of your webhook rules are going to be the same (i.e. the webhook callback_url is not unique to each user, and you need to monitor the same folders for all users), you should use application level webhooks.
Application level webhooks apply to your entire user base.
Good candidates for application level webhooks would be applications where you have to monitor the Inbox and Sent folders. By default, a webhook with no filters monitors the Inbox and Sent folders, so setting an application level webhook with no filters would monitor the Inbox and Sent folders for all of the users in your user base.