diff --git a/core/pkg/service/sync/handler.go b/core/pkg/service/sync/handler.go
index 2e2ceb33c..3ab2fb457 100644
--- a/core/pkg/service/sync/handler.go
+++ b/core/pkg/service/sync/handler.go
@@ -12,7 +12,7 @@ import (
 
 type handler struct {
 	rpc.UnimplementedFlagSyncServiceServer
-	syncStore *syncStore.SyncStore
+	syncStore syncStore.ISyncStore
 	logger    *logger.Logger
 }
 
diff --git a/core/pkg/service/sync/server.go b/core/pkg/service/sync/server.go
index dea29ac36..80a0195e6 100644
--- a/core/pkg/service/sync/server.go
+++ b/core/pkg/service/sync/server.go
@@ -25,12 +25,11 @@ type Server struct {
 	config        iservice.Configuration
 }
 
-func NewServer(ctx context.Context, logger *logger.Logger) *Server {
-	syncStore := syncStore.NewSyncStore(ctx, logger)
+func NewServer(logger *logger.Logger, store syncStore.ISyncStore) *Server {
 	return &Server{
 		handler: &handler{
 			logger:    logger,
-			syncStore: syncStore,
+			syncStore: store,
 		},
 		Logger: logger,
 	}
diff --git a/core/pkg/sync-store/interface.go b/core/pkg/sync-store/interface.go
new file mode 100644
index 000000000..3e5a71977
--- /dev/null
+++ b/core/pkg/sync-store/interface.go
@@ -0,0 +1,26 @@
+package store
+
+import (
+	"context"
+
+	isync "github.com/open-feature/flagd/core/pkg/sync"
+)
+
+// ISyncStore defines the interface for the sync store
+type ISyncStore interface {
+	FetchAllFlags(
+		ctx context.Context,
+		key interface{},
+		target string,
+	) (isync.DataSync, error)
+	RegisterSubscription(
+		ctx context.Context,
+		target string,
+		key interface{},
+		dataSync chan isync.DataSync,
+		errChan chan error,
+	)
+
+	// metrics hooks
+	GetActiveSubscriptionsInt64() int64
+}
diff --git a/flagd-proxy/cmd/start.go b/flagd-proxy/cmd/start.go
index b7df5b241..a145f0fbf 100644
--- a/flagd-proxy/cmd/start.go
+++ b/flagd-proxy/cmd/start.go
@@ -13,6 +13,7 @@ import (
 	"github.com/open-feature/flagd/core/pkg/logger"
 	"github.com/open-feature/flagd/core/pkg/service"
 	syncServer "github.com/open-feature/flagd/core/pkg/service/sync"
+	syncStore "github.com/open-feature/flagd/core/pkg/sync-store"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"go.uber.org/zap/zapcore"
@@ -61,7 +62,8 @@ var startCmd = &cobra.Command{
 
 		ctx, _ := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 
-		s := syncServer.NewServer(ctx, logger)
+		syncStore := syncStore.NewSyncStore(ctx, logger)
+		s := syncServer.NewServer(logger, syncStore)
 		cfg := service.Configuration{
 			ReadinessProbe: func() bool { return true },
 			Port:           viper.GetUint16(portFlagName),