Sync and cloud storage

*.apple-cloudkit.com

Hosts under apple-cloudkit.com belong to Apple's CloudKit, the iCloud service that apps use to store and sync data. Apple also lists api.apple-cloudkit.com for app notarization on macOS.

Run by ApplePorts: 443 TCPChecked: 1 November 2026

Short answer

Apple's CloudKit service. Apps sync their iCloud data through it, and Apple lists api.apple-cloudkit.com for app notarization on macOS.

Don’t block

Don't block it. iCloud sync for many apps stops, and macOS can't do notarization checks for apps.

Matches
*.apple-cloudkit.com

A name with *. covers every name under it: *.push.apple.com matches 1-courier.push.apple.com.

What it serves

Apple's enterprise host list names *.apple-cloudkit.com in its iCloud section, for “iCloud services”, on TCP port 443.

In the “Apps and additional content” section, Apple lists api.apple-cloudkit.com for “App notarization” on macOS. Gatekeeper's online checks need it.

On a Mac, cloudd backs CloudKit, so most CloudKit traffic shows under it. Apple Platform Security also says that Screen Time and iCloud Keychain data sync through CloudKit.

Processes that use it

clouddPart of macOS. It syncs the iCloud data of apps that use CloudKit, so its traffic belongs to those apps.Process →syspolicydPart of macOS. It runs the system policy that includes Gatekeeper, which checks new and changed apps for known malware and revoked certificates.Process →ScreenTimeAgentPart of macOS. It supports Screen Time, which can sync your usage and limits across your devices through iCloud.Process →secdPart of macOS. It controls access to keychain items. With iCloud Keychain on, your passwords and other synced items travel between your devices.Process →siriactionsdPart of macOS. It runs and syncs the shortcuts you make in the Shortcuts app, so iCloud sync of shortcuts can show under it.Process →

What breaks if you block it

Don’t block

Don't block it. iCloud sync for many apps stops, and macOS can't do notarization checks for apps.

What breaks if you block it

  • Apps that keep data in iCloud stop syncing between your devices.
  • Gatekeeper's notarization checks can't reach Apple.
  • Screen Time and iCloud Keychain sync stop, since Apple says that they use CloudKit.

With Kilobat Pro and the network filter, you can block a host for every app or for one app: in Connections, select a connection and choose Block. Apple’s own services are never blocked by Kilobat’s Protection lists.

Notes

Apple says that its services fail any connection that uses HTTPS interception. A proxy that inspects TLS breaks CloudKit.

Apple’s rules for its hosts

Apple’s list, Use Apple products on enterprise networks, says that devices open these connections, not Apple’s servers. Apple services fail any connection that uses HTTPS interception, so a proxy that inspects TLS should leave Apple’s hosts alone.

If a firewall allows hosts by name, allowing *.apple.com covers most Apple services, Apple says. A firewall that works only with addresses can allow 17.0.0.0/8 for IPv4, and 2403:300::/32, 2620:149::/32 and 2a01:b740::/32 for IPv6.

To see which app on your Mac opened a connection to this host, use Kilobat’s Connections tab, or the agent network log for AI agents.

Sources

Checked on 1 November 2026.