diff --git a/doc/thinking/2026-04-26-namespace-manager-step25.md b/doc/thinking/2026-04-26-namespace-manager-step25.md
new file mode 100644
index 00000000..671b76cc
--- /dev/null
+++ b/doc/thinking/2026-04-26-namespace-manager-step25.md
@@ -0,0 +1,17 @@
+# 2026-04-26 — NamespaceManager rewrite, step 25
+
+## Цель шага
+
+Добавить runtime adapter для `executor/multitenant` поверх уже выделенного helper-а.
+
+## Что меняем
+
+1. Добавляем executor namespace subscriber.
+2. `add/resync` path переиспользует `registerNamespace()`.
+3. Добавляем unit test на вызов executor type-ов.
+
+## Что НЕ меняем
+
+- не подключаем subscriber к watcher-у;
+- не меняем remove path;
+- не меняем внешний API watcher-а.
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diff --git a/pkg/executor/multitenant/namespace_subscriber.go b/pkg/executor/multitenant/namespace_subscriber.go
new file mode 100644
index 00000000..c4178e4e
--- /dev/null
+++ b/pkg/executor/multitenant/namespace_subscriber.go
@@ -0,0 +1,32 @@
+package multitenant
+
+import (
+	"context"
+
+	"go.uber.org/zap"
+	"k8s.io/client-go/kubernetes"
+
+	fv1 "github.com/fission/fission/pkg/apis/core/v1"
+	"github.com/fission/fission/pkg/executor/executortype"
+	"github.com/fission/fission/pkg/utils"
+	"github.com/fission/fission/pkg/utils/manager"
+)
+
+func NewNamespaceSubscriber(
+	logger *zap.Logger,
+	kubernetesClient kubernetes.Interface,
+	executorTypes map[fv1.ExecutorType]executortype.ExecutorType,
+	mgr manager.Interface,
+) utils.NamespaceSubscriber {
+	return utils.NamespaceSubscriberFuncs{
+		SubscriberName: "executor",
+		AddFunc: func(ctx context.Context, record utils.NamespaceRecord) error {
+			registerNamespace(ctx, logger, kubernetesClient, record.Name, executorTypes, mgr)
+			return nil
+		},
+		ResyncFunc: func(ctx context.Context, record utils.NamespaceRecord) error {
+			registerNamespace(ctx, logger, kubernetesClient, record.Name, executorTypes, mgr)
+			return nil
+		},
+	}
+}
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diff --git a/pkg/executor/multitenant/namespace_subscriber_test.go b/pkg/executor/multitenant/namespace_subscriber_test.go
new file mode 100644
index 00000000..abecb9a0
--- /dev/null
+++ b/pkg/executor/multitenant/namespace_subscriber_test.go
@@ -0,0 +1,37 @@
+package multitenant
+
+import (
+	"context"
+	"testing"
+
+	"go.uber.org/zap"
+	k8sfake "k8s.io/client-go/kubernetes/fake"
+
+	fv1 "github.com/fission/fission/pkg/apis/core/v1"
+	"github.com/fission/fission/pkg/executor/executortype"
+	"github.com/fission/fission/pkg/utils"
+)
+
+func TestNewNamespaceSubscriberAddAndResync(t *testing.T) {
+	poolmgr := &fakeExecutorType{}
+	subscriber := NewNamespaceSubscriber(zap.NewNop(), k8sfake.NewSimpleClientset(), map[fv1.ExecutorType]executortype.ExecutorType{
+		fv1.ExecutorTypePoolmgr: poolmgr,
+	}, nil)
+	record := utils.NamespaceRecord{Name: "tenant-executor-b"}
+
+	if subscriber.Name() != "executor" {
+		t.Fatalf("expected executor subscriber name")
+	}
+	if err := subscriber.OnNamespaceAdd(context.Background(), record); err != nil {
+		t.Fatalf("expected add to succeed: %v", err)
+	}
+	if err := subscriber.OnNamespaceResync(context.Background(), record); err != nil {
+		t.Fatalf("expected resync to succeed: %v", err)
+	}
+	if poolmgr.addCalls != 2 {
+		t.Fatalf("expected executor type to receive add and resync calls")
+	}
+	if poolmgr.lastNamespace != "tenant-executor-b" {
+		t.Fatalf("expected namespace to be forwarded to executor type")
+	}
+}
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