Deprecated Kernel Extensions and System Extension Alternatives -
Support
By Apple Inc.
Archived: 2026-04-06 00:38:39 UTC
System extensions on macOS Catalina 10.15 or later allow software, such as network extensions and endpoint
security solutions, to extend the functionality of macOS without requiring kernel-level access. As part of our
ongoing effort to modernize the platform, improve security and reliability, and enable more user-friendly
distribution methods, kernel extensions have been deprecated. Starting with macOS Big Sur, macOS releases no
longer load kernel extensions that use deprecated kernel programming interfaces (KPIs) by default.
Transitioning your kernel extensions
Certain kernel extensions are unsupported on macOS Big Sur. If your software uses deprecated and supported
KPIs for older versions of macOS, you’ll need to factor out deprecated components into a stand-alone system
extension. If your software uses new system extensions and legacy kernel extensions, you can distribute to
supported operating systems. Software that supports a broad range of macOS versions should continue to use
kernel extensions for older versions and run system extensions where supported.
Below is a list of unsupported KPIs as of macOS Big Sur. Any kernel extension using an unsupported KPI will not
load.*
KAUTH
Unsupported: macOS Big Sur 11.0
Deprecated: macOS Catalina 10.15
The following KPIs are unsupported in macOS Big Sur. Clients should use EndpointSecurity instead.
kauth_listen_scope
kauth_unlisten_scope
Socket
Deprecated: macOS Catalina 10.15
The following Socket KPIs continue to be deprecated in macOS Big Sur. Clients should use NetworkExtension
instead.
sock_accept
sock_bind
sock_close
https://developer.apple.com/support/kernel-extensions/
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sock_connect
sock_getpeername
sock_getsockname
sock_getsockopt
sock_gettype
sock_ioctl
sock_isconnected
sock_isnonblocking
sock_listen
sock_receive
sock_receivembuf
sock_release
sock_retain
sock_send
sock_sendmbuf
sock_setsockopt
sock_shutdown
sock_socket
Network filter
Unsupported: macOS Big Sur 11.0
Deprecated: macOS Catalina 10.15
The following Network Filter KPIs are unsupported in macOS Big Sur:
ipf_addv4
ipf_addv6
ipf_inject_input
ipf_inject_output
ipf_remove
sflt_attach
sflt_detach
sflt_register
sflt_unregister
sock_inject_data_in
sock_inject_data_out
sock_setpriv
sockopt_copyin
sockopt_copyout
sockopt_direction
sockopt_level
sockopt_name
sockopt_valsize
https://developer.apple.com/support/kernel-extensions/
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IOHIDFamily
Unsupported: macOS Big Sur 11.0
Deprecated: macOS Catalina 10.15
All KPIs in IOHIDFamily are unsupported in macOS Big Sur. Clients should use HIDDriverKit instead.
IOUSBFamily
Unsupported: macOS Big Sur 11.0
Deprecated: OS X El Capitan 10.11
All KPIs in IOUSBFamily are unsupported in macOS Big Sur. Clients should move to IOUSBHostFamily or
USBDriverKit, where appropriate and as outlined below.
USB networking
Unsupported: macOS Big Sur 11.0
Deprecated: macOS Catalina 10.15
The combination of using IONetworkingFamily KPIs as well as any USB KPI (IOUSBHostFamily or
IOUSBFamily) is unsupported in macOS Big Sur. USB KPIs have alternatives in USBDriverKit. Clients of
IONetworkingFamily KPIs should use NetworkingDriverKit instead.
USB serial
Unsupported: macOS Big Sur 11.0
Deprecated: macOS Catalina 10.15
The combination of using any IOSerialFamily KPI as well as any USB KPI (IOUSBHostFamily or
IOUSBFamily) is unsupported in macOS Big Sur. USB KPIs have alternatives in USBDriverKit. Clients of
IOSerialFamily KPIs should use SerialDriverKit or USBSerialDriverKit instead.
USB vendor-specific IPC
Unsupported: macOS Big Sur 11.0
Deprecated: macOS Catalina 10.15
Any kernel extension using USB KPI (IOUSBHostFamily or IOUSBFamily) that doesn't tie into the IO Family
subsystem and uses IOUserClient, or subclasses, for IPC is unsupported in macOS Big Sur. USB KPIs have
alternatives in USBDriverKit or consider IOUSBHost framework. DriverKit also has mechanisms for
communication channels.
PCI networking
https://developer.apple.com/support/kernel-extensions/
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Unsupported: macOS Big Sur 11.0
Deprecated: macOS Catalina 10.15
The combination of using IONetworkingFamily KPIs as well as IOPCIFamily KPIs is deprecated. PCI KPIs have
alternatives in PCIDriverKit. Clients of IONetworkingFamily KPIs should use NetworkingDriverKit instead.
IOAudioFamily
Deprecated: macOS Monterey 12.3
All KPIs in IOAudioFamily are deprecated in macOS Monterey 12.3. Clients should use AudioDriverKit instead.
IOBluetoothHIDDriver
Deprecated: macOS Monterey 12.3
All KPIs in IOBluetoothHIDDriver are deprecated in macOS Monterey 12.3. Bluetooth LE clients should use
CoreBluetooth instead. Bluetooth "Classic" is no longer supported.
IOSCSIParallelFamily
Deprecated: macOS Monterey 12.3
All KPIs in IOSCSIParallelFamily are deprecated in macOS Monterey 12.3. Clients should use
SCISControllerDriverKit instead.
Contacting us
Entitlements
To deploy drivers built with DriverKit or use the EndpointSecurity API, you’ll need an entitlement from Apple.
Request an entitlement
Feedback
Your feedback is valuable and helps inform the direction of our system extension development. Send us your API
enhancement requests or bug reports through Feedback Assistant.
Provide feedback
Source: https://developer.apple.com/support/kernel-extensions/
https://developer.apple.com/support/kernel-extensions/
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