Preserve context in action registration

action.go

@@ -36,6 +36,18 @@ type ActionRegistrar interface {
 	RegisterAction(name string, invoke func(map[string]any) (any, bool, error))
 }
 
+// ActionContextRegistrar publishes DNS actions while preserving caller context.
+//
+//	registrar.RegisterActionContext(
+//		ActionDiscover,
+//		func(ctx context.Context, values map[string]any) (any, bool, error) {
+//			return service.HandleActionContext(ctx, ActionDiscover, values)
+//		},
+//	)
+type ActionContextRegistrar interface {
+	RegisterActionContext(name string, invoke func(context.Context, map[string]any) (any, bool, error))
+}
+
 // ActionCaller resolves named actions from another Core surface.
 //
 //	aliases, ok, err := caller.CallAction(
@@ -148,6 +160,20 @@ func (service *Service) RegisterActions(registrar ActionRegistrar) {
 	if registrar == nil {
 		return
 	}
+
+	if contextRegistrar, ok := registrar.(ActionContextRegistrar); ok {
+		for _, definition := range service.ActionDefinitions() {
+			invoke := definition.InvokeContext
+			if invoke == nil {
+				invoke = func(ctx context.Context, values map[string]any) (any, bool, error) {
+					return definition.Invoke(values)
+				}
+			}
+			contextRegistrar.RegisterActionContext(definition.Name, invoke)
+		}
+		return
+	}
+
 	for _, definition := range service.ActionDefinitions() {
 		registrar.RegisterAction(definition.Name, definition.Invoke)
 	}

service_test.go

@@ -2145,6 +2145,49 @@ func TestServiceRegisterActionsPublishesAllActionsInOrder(t *testing.T) {
 	}
 }
 
+func TestServiceRegisterActionsUsesContextAwareRegistrarWhenAvailable(t *testing.T) {
+	type ctxKey string
+
+	registrar := &actionContextRecorder{}
+	service := NewService(ServiceOptions{
+		ChainAliasDiscoverer: func(ctx context.Context) ([]string, error) {
+			value, ok := ctx.Value(ctxKey("discover-token")).(string)
+			if !ok {
+				t.Fatal("expected discover context to be preserved")
+			}
+			if value != "preserved" {
+				t.Fatalf("unexpected discover context value: %q", value)
+			}
+			return []string{"gateway.charon.lthn"}, nil
+		},
+		HSDClient: NewHSDClient(HSDClientOptions{
+			URL: "http://127.0.0.1:1",
+		}),
+	})
+
+	service.RegisterActions(registrar)
+
+	invoke, ok := registrar.contextHandlers[ActionDiscover]
+	if !ok {
+		t.Fatal("expected context-aware registrar to receive discover action")
+	}
+
+	ctx := context.WithValue(context.Background(), ctxKey("discover-token"), "preserved")
+	payload, succeeded, err := invoke(ctx, nil)
+	if err == nil {
+		t.Fatal("expected discover action to fail without an HSD endpoint")
+	}
+	if succeeded {
+		t.Fatal("expected discover action to report failure")
+	}
+	if payload != nil {
+		t.Fatalf("expected no payload on failure, got %#v", payload)
+	}
+	if !strings.Contains(err.Error(), "connection refused") && !strings.Contains(err.Error(), "hsd rpc request failed") {
+		t.Fatalf("expected discover action to propagate the HSD client error, got %v", err)
+	}
+}
+
 func TestNewServiceWithRegistrarBuildsAndRegistersInOneStep(t *testing.T) {
 	registrar := &actionRecorder{}
 	service := NewServiceWithRegistrar(ServiceOptions{
@@ -2411,6 +2454,29 @@ func (recorder *actionRecorder) RegisterAction(name string, invoke func(map[stri
 	recorder.handlers[name] = invoke
 }
 
+type actionContextRecorder struct {
+	names           []string
+	contextHandlers map[string]func(context.Context, map[string]any) (any, bool, error)
+}
+
+func (recorder *actionContextRecorder) RegisterAction(name string, invoke func(map[string]any) (any, bool, error)) {
+	if recorder.contextHandlers == nil {
+		recorder.contextHandlers = map[string]func(context.Context, map[string]any) (any, bool, error){}
+	}
+	recorder.names = append(recorder.names, name)
+	recorder.contextHandlers[name] = func(ctx context.Context, values map[string]any) (any, bool, error) {
+		return invoke(values)
+	}
+}
+
+func (recorder *actionContextRecorder) RegisterActionContext(name string, invoke func(context.Context, map[string]any) (any, bool, error)) {
+	if recorder.contextHandlers == nil {
+		recorder.contextHandlers = map[string]func(context.Context, map[string]any) (any, bool, error){}
+	}
+	recorder.names = append(recorder.names, name)
+	recorder.contextHandlers[name] = invoke
+}
+
 type actionCallerFunc func(context.Context, string, map[string]any) (any, bool, error)
 
 func (caller actionCallerFunc) CallAction(ctx context.Context, name string, values map[string]any) (any, bool, error) {