diff --git a/unix/darwin_amd64_test.go b/unix/darwin_amd64_test.go
index b6dac524c..f89b50e71 100644
--- a/unix/darwin_amd64_test.go
+++ b/unix/darwin_amd64_test.go
@@ -22,6 +22,7 @@ var darwinTests = [...]darwinTest{
 	{"close", libc_close_trampoline_addr},
 	{"closedir", libc_closedir_trampoline_addr},
 	{"connect", libc_connect_trampoline_addr},
+	{"connectx", libc_connectx_trampoline_addr},
 	{"dup", libc_dup_trampoline_addr},
 	{"dup2", libc_dup2_trampoline_addr},
 	{"exchangedata", libc_exchangedata_trampoline_addr},
diff --git a/unix/darwin_arm64_test.go b/unix/darwin_arm64_test.go
index 5a310de02..5fc4feb44 100644
--- a/unix/darwin_arm64_test.go
+++ b/unix/darwin_arm64_test.go
@@ -22,6 +22,7 @@ var darwinTests = [...]darwinTest{
 	{"close", libc_close_trampoline_addr},
 	{"closedir", libc_closedir_trampoline_addr},
 	{"connect", libc_connect_trampoline_addr},
+	{"connectx", libc_connectx_trampoline_addr},
 	{"dup", libc_dup_trampoline_addr},
 	{"dup2", libc_dup2_trampoline_addr},
 	{"exchangedata", libc_exchangedata_trampoline_addr},
diff --git a/unix/mkerrors.sh b/unix/mkerrors.sh
index d07dd09eb..e14b766a3 100755
--- a/unix/mkerrors.sh
+++ b/unix/mkerrors.sh
@@ -552,6 +552,7 @@ ccflags="$@"
 		$2 !~ /^RTC_VL_(ACCURACY|BACKUP|DATA)/ &&
 		$2 ~ /^(NETLINK|NLM|NLMSG|NLA|IFA|IFAN|RT|RTC|RTCF|RTN|RTPROT|RTNH|ARPHRD|ETH_P|NETNSA)_/ ||
 		$2 ~ /^SOCK_|SK_DIAG_|SKNLGRP_$/ ||
+		$2 ~ /^(CONNECT|SAE)_/ ||
 		$2 ~ /^FIORDCHK$/ ||
 		$2 ~ /^SIOC/ ||
 		$2 ~ /^TIOC/ ||
diff --git a/unix/syscall_darwin.go b/unix/syscall_darwin.go
index 2d15200ad..099867dee 100644
--- a/unix/syscall_darwin.go
+++ b/unix/syscall_darwin.go
@@ -566,6 +566,43 @@ func PthreadFchdir(fd int) (err error) {
 	return pthread_fchdir_np(fd)
 }
 
+// Connectx calls connectx(2) to initiate a connection on a socket.
+//
+// srcIf, srcAddr, and dstAddr are filled into a [SaEndpoints] struct and passed as the endpoints argument.
+//
+//   - srcIf is the optional source interface index. 0 means unspecified.
+//   - srcAddr is the optional source address. nil means unspecified.
+//   - dstAddr is the destination address.
+//
+// On success, Connectx returns the number of bytes enqueued for transmission.
+func Connectx(fd int, srcIf uint32, srcAddr, dstAddr Sockaddr, associd SaeAssocID, flags uint32, iov []Iovec, connid *SaeConnID) (n uintptr, err error) {
+	endpoints := SaEndpoints{
+		Srcif: srcIf,
+	}
+
+	if srcAddr != nil {
+		addrp, addrlen, err := srcAddr.sockaddr()
+		if err != nil {
+			return 0, err
+		}
+		endpoints.Srcaddr = (*RawSockaddr)(addrp)
+		endpoints.Srcaddrlen = uint32(addrlen)
+	}
+
+	if dstAddr != nil {
+		addrp, addrlen, err := dstAddr.sockaddr()
+		if err != nil {
+			return 0, err
+		}
+		endpoints.Dstaddr = (*RawSockaddr)(addrp)
+		endpoints.Dstaddrlen = uint32(addrlen)
+	}
+
+	err = connectx(fd, &endpoints, associd, flags, iov, &n, connid)
+	return
+}
+
+//sys	connectx(fd int, endpoints *SaEndpoints, associd SaeAssocID, flags uint32, iov []Iovec, n *uintptr, connid *SaeConnID) (err error)
 //sys	sendfile(infd int, outfd int, offset int64, len *int64, hdtr unsafe.Pointer, flags int) (err error)
 
 //sys	shmat(id int, addr uintptr, flag int) (ret uintptr, err error)
diff --git a/unix/types_darwin.go b/unix/types_darwin.go
index 7ed32a1a5..36e2f045d 100644
--- a/unix/types_darwin.go
+++ b/unix/types_darwin.go
@@ -177,6 +177,12 @@ type XVSockPgen C.struct_xvsockpgen
 
 type _Socklen C.socklen_t
 
+type SaeAssocID C.sae_associd_t
+
+type SaeConnID C.sae_connid_t
+
+type SaEndpoints C.struct_sa_endpoints
+
 type Xucred C.struct_xucred
 
 type Linger C.struct_linger
diff --git a/unix/zerrors_darwin_amd64.go b/unix/zerrors_darwin_amd64.go
index 4308ac177..d73c4652e 100644
--- a/unix/zerrors_darwin_amd64.go
+++ b/unix/zerrors_darwin_amd64.go
@@ -237,6 +237,9 @@ const (
 	CLOCK_UPTIME_RAW_APPROX                 = 0x9
 	CLONE_NOFOLLOW                          = 0x1
 	CLONE_NOOWNERCOPY                       = 0x2
+	CONNECT_DATA_AUTHENTICATED              = 0x4
+	CONNECT_DATA_IDEMPOTENT                 = 0x2
+	CONNECT_RESUME_ON_READ_WRITE            = 0x1
 	CR0                                     = 0x0
 	CR1                                     = 0x1000
 	CR2                                     = 0x2000
@@ -1265,6 +1268,10 @@ const (
 	RTV_SSTHRESH                            = 0x20
 	RUSAGE_CHILDREN                         = -0x1
 	RUSAGE_SELF                             = 0x0
+	SAE_ASSOCID_ALL                         = 0xffffffff
+	SAE_ASSOCID_ANY                         = 0x0
+	SAE_CONNID_ALL                          = 0xffffffff
+	SAE_CONNID_ANY                          = 0x0
 	SCM_CREDS                               = 0x3
 	SCM_RIGHTS                              = 0x1
 	SCM_TIMESTAMP                           = 0x2
diff --git a/unix/zerrors_darwin_arm64.go b/unix/zerrors_darwin_arm64.go
index c8068a7a1..4a55a4005 100644
--- a/unix/zerrors_darwin_arm64.go
+++ b/unix/zerrors_darwin_arm64.go
@@ -237,6 +237,9 @@ const (
 	CLOCK_UPTIME_RAW_APPROX                 = 0x9
 	CLONE_NOFOLLOW                          = 0x1
 	CLONE_NOOWNERCOPY                       = 0x2
+	CONNECT_DATA_AUTHENTICATED              = 0x4
+	CONNECT_DATA_IDEMPOTENT                 = 0x2
+	CONNECT_RESUME_ON_READ_WRITE            = 0x1
 	CR0                                     = 0x0
 	CR1                                     = 0x1000
 	CR2                                     = 0x2000
@@ -1265,6 +1268,10 @@ const (
 	RTV_SSTHRESH                            = 0x20
 	RUSAGE_CHILDREN                         = -0x1
 	RUSAGE_SELF                             = 0x0
+	SAE_ASSOCID_ALL                         = 0xffffffff
+	SAE_ASSOCID_ANY                         = 0x0
+	SAE_CONNID_ALL                          = 0xffffffff
+	SAE_CONNID_ANY                          = 0x0
 	SCM_CREDS                               = 0x3
 	SCM_RIGHTS                              = 0x1
 	SCM_TIMESTAMP                           = 0x2
diff --git a/unix/zsyscall_darwin_amd64.go b/unix/zsyscall_darwin_amd64.go
index b622533ef..24b346e1a 100644
--- a/unix/zsyscall_darwin_amd64.go
+++ b/unix/zsyscall_darwin_amd64.go
@@ -841,6 +841,26 @@ var libc_pthread_fchdir_np_trampoline_addr uintptr
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func connectx(fd int, endpoints *SaEndpoints, associd SaeAssocID, flags uint32, iov []Iovec, n *uintptr, connid *SaeConnID) (err error) {
+	var _p0 unsafe.Pointer
+	if len(iov) > 0 {
+		_p0 = unsafe.Pointer(&iov[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := syscall_syscall9(libc_connectx_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(endpoints)), uintptr(associd), uintptr(flags), uintptr(_p0), uintptr(len(iov)), uintptr(unsafe.Pointer(n)), uintptr(unsafe.Pointer(connid)), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+var libc_connectx_trampoline_addr uintptr
+
+//go:cgo_import_dynamic libc_connectx connectx "/usr/lib/libSystem.B.dylib"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func sendfile(infd int, outfd int, offset int64, len *int64, hdtr unsafe.Pointer, flags int) (err error) {
 	_, _, e1 := syscall_syscall6(libc_sendfile_trampoline_addr, uintptr(infd), uintptr(outfd), uintptr(offset), uintptr(unsafe.Pointer(len)), uintptr(hdtr), uintptr(flags))
 	if e1 != 0 {
diff --git a/unix/zsyscall_darwin_amd64.s b/unix/zsyscall_darwin_amd64.s
index cfe6646ba..ebd213100 100644
--- a/unix/zsyscall_darwin_amd64.s
+++ b/unix/zsyscall_darwin_amd64.s
@@ -248,6 +248,11 @@ TEXT libc_pthread_fchdir_np_trampoline<>(SB),NOSPLIT,$0-0
 GLOBL	·libc_pthread_fchdir_np_trampoline_addr(SB), RODATA, $8
 DATA	·libc_pthread_fchdir_np_trampoline_addr(SB)/8, $libc_pthread_fchdir_np_trampoline<>(SB)
 
+TEXT libc_connectx_trampoline<>(SB),NOSPLIT,$0-0
+	JMP	libc_connectx(SB)
+GLOBL	·libc_connectx_trampoline_addr(SB), RODATA, $8
+DATA	·libc_connectx_trampoline_addr(SB)/8, $libc_connectx_trampoline<>(SB)
+
 TEXT libc_sendfile_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sendfile(SB)
 GLOBL	·libc_sendfile_trampoline_addr(SB), RODATA, $8
diff --git a/unix/zsyscall_darwin_arm64.go b/unix/zsyscall_darwin_arm64.go
index 13f624f69..824b9c2d5 100644
--- a/unix/zsyscall_darwin_arm64.go
+++ b/unix/zsyscall_darwin_arm64.go
@@ -841,6 +841,26 @@ var libc_pthread_fchdir_np_trampoline_addr uintptr
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func connectx(fd int, endpoints *SaEndpoints, associd SaeAssocID, flags uint32, iov []Iovec, n *uintptr, connid *SaeConnID) (err error) {
+	var _p0 unsafe.Pointer
+	if len(iov) > 0 {
+		_p0 = unsafe.Pointer(&iov[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := syscall_syscall9(libc_connectx_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(endpoints)), uintptr(associd), uintptr(flags), uintptr(_p0), uintptr(len(iov)), uintptr(unsafe.Pointer(n)), uintptr(unsafe.Pointer(connid)), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+var libc_connectx_trampoline_addr uintptr
+
+//go:cgo_import_dynamic libc_connectx connectx "/usr/lib/libSystem.B.dylib"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func sendfile(infd int, outfd int, offset int64, len *int64, hdtr unsafe.Pointer, flags int) (err error) {
 	_, _, e1 := syscall_syscall6(libc_sendfile_trampoline_addr, uintptr(infd), uintptr(outfd), uintptr(offset), uintptr(unsafe.Pointer(len)), uintptr(hdtr), uintptr(flags))
 	if e1 != 0 {
diff --git a/unix/zsyscall_darwin_arm64.s b/unix/zsyscall_darwin_arm64.s
index fe222b75d..4f178a229 100644
--- a/unix/zsyscall_darwin_arm64.s
+++ b/unix/zsyscall_darwin_arm64.s
@@ -248,6 +248,11 @@ TEXT libc_pthread_fchdir_np_trampoline<>(SB),NOSPLIT,$0-0
 GLOBL	·libc_pthread_fchdir_np_trampoline_addr(SB), RODATA, $8
 DATA	·libc_pthread_fchdir_np_trampoline_addr(SB)/8, $libc_pthread_fchdir_np_trampoline<>(SB)
 
+TEXT libc_connectx_trampoline<>(SB),NOSPLIT,$0-0
+	JMP	libc_connectx(SB)
+GLOBL	·libc_connectx_trampoline_addr(SB), RODATA, $8
+DATA	·libc_connectx_trampoline_addr(SB)/8, $libc_connectx_trampoline<>(SB)
+
 TEXT libc_sendfile_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sendfile(SB)
 GLOBL	·libc_sendfile_trampoline_addr(SB), RODATA, $8
diff --git a/unix/ztypes_darwin_amd64.go b/unix/ztypes_darwin_amd64.go
index 091d107f3..d003c3d43 100644
--- a/unix/ztypes_darwin_amd64.go
+++ b/unix/ztypes_darwin_amd64.go
@@ -306,6 +306,19 @@ type XVSockPgen struct {
 
 type _Socklen uint32
 
+type SaeAssocID uint32
+
+type SaeConnID uint32
+
+type SaEndpoints struct {
+	Srcif      uint32
+	Srcaddr    *RawSockaddr
+	Srcaddrlen uint32
+	Dstaddr    *RawSockaddr
+	Dstaddrlen uint32
+	_          [4]byte
+}
+
 type Xucred struct {
 	Version uint32
 	Uid     uint32
diff --git a/unix/ztypes_darwin_arm64.go b/unix/ztypes_darwin_arm64.go
index 28ff4ef74..0d45a941a 100644
--- a/unix/ztypes_darwin_arm64.go
+++ b/unix/ztypes_darwin_arm64.go
@@ -306,6 +306,19 @@ type XVSockPgen struct {
 
 type _Socklen uint32
 
+type SaeAssocID uint32
+
+type SaeConnID uint32
+
+type SaEndpoints struct {
+	Srcif      uint32
+	Srcaddr    *RawSockaddr
+	Srcaddrlen uint32
+	Dstaddr    *RawSockaddr
+	Dstaddrlen uint32
+	_          [4]byte
+}
+
 type Xucred struct {
 	Version uint32
 	Uid     uint32