diff --git a/internal/hooks/client_header.go b/internal/hooks/client_header.go
new file mode 100644
index 0000000..7823f28
--- /dev/null
+++ b/internal/hooks/client_header.go
@@ -0,0 +1,45 @@
+package hooks
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/sfcompute/sfc-go/internal/config"
+)
+
+// sfcClientHeader is the canonical header used by SFC services to identify
+// SDK clients. The server-side parser relies on this header rather than the
+// generated User-Agent so that our parsing does not break if Speakeasy
+// changes the User-Agent format.
+const sfcClientHeader = "x-sfc-client"
+
+// ClientHeaderHook sets the x-sfc-client header on every outgoing request.
+// The version is captured from the generated User-Agent at SDK init time.
+type ClientHeaderHook struct {
+	headerValue string
+}
+
+func (h *ClientHeaderHook) SDKInit(c config.SDKConfiguration) config.SDKConfiguration {
+	h.headerValue = "speakeasy/go-" + parseSDKVersion(c.UserAgent)
+	return c
+}
+
+func (h *ClientHeaderHook) BeforeRequest(_ BeforeRequestContext, req *http.Request) (*http.Request, error) {
+	req.Header.Set(sfcClientHeader, h.headerValue)
+	return req, nil
+}
+
+// parseSDKVersion extracts the SDK version (second token) from the
+// Speakeasy-generated User-Agent string of the form:
+//
+//	"speakeasy-sdk/go <sdkVersion> <generatorVersion> <docVersion> <module>"
+//
+// Returns "unknown" if the User-Agent is empty or does not have at least two
+// space-separated tokens.
+func parseSDKVersion(userAgent string) string {
+	parts := strings.Fields(userAgent)
+	if len(parts) < 2 {
+		return "unknown"
+	}
+	return parts[1]
+}
diff --git a/internal/hooks/client_header_test.go b/internal/hooks/client_header_test.go
new file mode 100644
index 0000000..7f6557f
--- /dev/null
+++ b/internal/hooks/client_header_test.go
@@ -0,0 +1,52 @@
+package hooks
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/sfcompute/sfc-go/internal/config"
+)
+
+func TestClientHeaderHook(t *testing.T) {
+	tests := []struct {
+		name      string
+		userAgent string
+		want      string
+	}{
+		{
+			name:      "speakeasy generated user agent",
+			userAgent: "speakeasy-sdk/go 0.0.1 2.881.17 0.1.0 github.com/sfcompute/sfc-go",
+			want:      "speakeasy/go-0.0.1",
+		},
+		{
+			name:      "empty user agent",
+			userAgent: "",
+			want:      "speakeasy/go-unknown",
+		},
+		{
+			name:      "single-token user agent",
+			userAgent: "speakeasy-sdk/go",
+			want:      "speakeasy/go-unknown",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			h := &ClientHeaderHook{}
+			h.SDKInit(config.SDKConfiguration{UserAgent: tc.userAgent})
+
+			req, err := http.NewRequest(http.MethodGet, "https://api.sfcompute.com/v1/foo", nil)
+			if err != nil {
+				t.Fatalf("NewRequest: %v", err)
+			}
+
+			if _, err := h.BeforeRequest(BeforeRequestContext{}, req); err != nil {
+				t.Fatalf("BeforeRequest: %v", err)
+			}
+
+			if got := req.Header.Get(sfcClientHeader); got != tc.want {
+				t.Errorf("x-sfc-client = %q, want %q", got, tc.want)
+			}
+		})
+	}
+}
diff --git a/internal/hooks/hooks.go b/internal/hooks/hooks.go
index 8651ce5..945b883 100644
--- a/internal/hooks/hooks.go
+++ b/internal/hooks/hooks.go
@@ -87,6 +87,8 @@ func New() *Hooks {
 		afterErrorHook:    []afterErrorHook{},
 	}
 
+	initHooks(h)
+
 	return h
 }
 
diff --git a/internal/hooks/registration.go b/internal/hooks/registration.go
new file mode 100644
index 0000000..c4b84f0
--- /dev/null
+++ b/internal/hooks/registration.go
@@ -0,0 +1,10 @@
+package hooks
+
+// initHooks is invoked by Hooks.New (in hooks.go) and registers all custom
+// hooks for this SDK. This file is user-owned and preserved across Speakeasy
+// regenerations.
+func initHooks(h *Hooks) {
+	clientHeader := &ClientHeaderHook{}
+	h.registerSDKInitHook(clientHeader)
+	h.registerBeforeRequestHook(clientHeader)
+}