Identifies this as a notification channel used to watch for changes to a resource, which is api#channel.

Date and time of notification channel expiration, expressed as a Unix timestamp, in milliseconds. Optional.

A Boolean value to indicate whether payload is wanted. Optional.

An arbitrary string delivered to the target address with each notification delivered over this channel. Optional.

The type of delivery mechanism used for this channel. Valid values are "web_hook" or "webhook".

The address where notifications are delivered for this channel.

An opaque ID that identifies the resource being watched on this channel. Stable across different API versions.

A version-specific identifier for the watched resource.

A UUID or similar unique string that identifies this channel.