diff --git a/lf/transition.mk b/lf/transition.mk
new file mode 100644
index 0000000..b8dbb9e
--- /dev/null
+++ b/lf/transition.mk
@@ -0,0 +1,70 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2024 Open Networking Foundation Contributors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# -----------------------------------------------------------------------
+# SPDX-FileCopyrightText: 2024 Open Networking Foundation Contributors
+# SPDX-License-Identifier: Apache-2.0
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+lf-sbx-root   := $(abspath $(lastword $(MAKEFILE_LIST)))
+lf-sbx-root   := $(subst /lf/transition.mk,$(null),$(lf-sbx-root))
+
+legacy-mk   ?= $(lf-sbx-root)/makefiles
+onf-mk-dir  ?= $(lf-sbx-root)/lf/onf-make/makefiles
+
+sandbox-root := $(lf-sbx-root)
+
+## -----------------------------------------------------------------------
+## Intent: on-demand submodule checkout when make targets are invoked
+## -----------------------------------------------------------------------
+GIT ?= /usr/bin/env git
+
+git-submodule-deps += $(onf-mk-dir)/consts.mk
+git-submodule-deps += $(onf-mk-dir)/etc/features.mk         # $(call banner-enter)
+git-submodule-deps += $(onf-mk-dir)/virtualenv/include.mk   # make venv
+git-submodule-deps += $(onf-mk-dir)/commands/pre-commit/include.mk
+
+# git-submodule-deps    : $(git-submodule-deps)
+
+$(git-submodule-deps) :
+
+	$(call banner-enter,(Checkout git submodules))
+	$(GIT) submodule update --init --recursive
+	$(call banner-leave,(Checkout git submodules))
+
+##--------------------##
+##---]  INCLUDES  [---##
+##--------------------##
+TOP ?= $(lf-sbx-root)
+
+##--------------------##
+##---]  INCLUDES  [---##
+##--------------------##
+include $(onf-mk-dir)/consts.mk
+include $(onf-mk-dir)/etc/features.mk         # $(call banner-enter)
+include $(onf-mk-dir)/virtualenv/include.mk   # make venv
+include $(onf-mk-dir)/commands/pre-commit/include.mk
+
+include $(TOP)/makefiles/include.mk      # top level include
+
+# dependency of virtualenv::sterile
+clean ::
+
+# [EOF]