diff --git a/CMakeLists.txt b/CMakeLists.txt
index 742690b..182523d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,10 +4,14 @@ project(WarthogJPS
 	VERSION 0.2.0
 	LANGUAGES CXX C)
 
+set_property(GLOBAL PROPERTY WARTHOG_warthog-jps ON)
+
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED TRUE)
 
-include(cmake/submodule.cmake)
+include(cmake/warthog.cmake)
+warthog_module_declare(warthog-core v0.5.0)
+warthog_module(warthog-core)
 
 add_library(warthog_libjps)
 add_library(warthog::libjps ALIAS warthog_libjps)
@@ -26,4 +30,3 @@ target_link_libraries(warthog_jps PUBLIC warthog::libjps)
 add_subdirectory(src)
 add_subdirectory(apps)
 
-warthog_submodule(warthog-core)
diff --git a/cmake/submodule.cmake b/cmake/submodule.cmake
deleted file mode 100644
index da47f29..0000000
--- a/cmake/submodule.cmake
+++ /dev/null
@@ -1,35 +0,0 @@
-cmake_minimum_required(VERSION 3.13)
-
-# include this file to check submodule include
-
-set(WARTHOG_SUBMODULE_ROOT_ONLY ON CACHE BOOL "add submodule if present only allowed for root project")
-
-function(warthog_top_level)
-set(_is_top OFF)
-if(${CMAKE_VERSION} VERSION_GREATER_EQUAL 3.21)
-	if(${PROJECT_IS_TOP_LEVEL})
-		set(_is_top ON)
-	endif()
-else()
-	if(${CMAKE_SOURCE_DIR} STREQUAL ${PROJECT_SOURCE_DIR})
-		set(_is_top ON)
-	endif()
-endif()
-set(_is_top ${_is_top} PARENT_SCOPE)
-endfunction()
-
-function(warthog_submodule dirname)
-set(_is_top OFF)
-if(NOT ${WARTHOG_SUBMODULE_ROOT_ONLY})
-	set(_is_top ON)
-else()
-	warthog_top_level()
-endif()
-if(${_is_top})
-	if(NOT EXISTS "${PROJECT_SOURCE_DIR}/extern/${dirname}/.git")
-		message(SEND_ERROR "Failed to find submodule ${dirname}")
-	else()
-		add_subdirectory("${PROJECT_SOURCE_DIR}/extern/${dirname}" EXCLUDE_FROM_ALL)
-	endif()
-endif()
-endfunction()
diff --git a/cmake/warthog.cmake b/cmake/warthog.cmake
new file mode 100644
index 0000000..635f050
--- /dev/null
+++ b/cmake/warthog.cmake
@@ -0,0 +1,76 @@
+cmake_minimum_required(VERSION 3.13)
+
+# include this file to check submodule include
+
+# set here as only
+set(warthog_https_warthog-core "https://github.com/ShortestPathLab/warthog-core.git" CACHE INTERNAL "")
+set(warthog_https_warthog-jps "https://github.com/ShortestPathLab/warthog-jps.git" CACHE INTERNAL "")
+
+if(COMMAND warthog_module)
+	return() # do not redefine
+endif()
+
+include(FetchContent)
+
+set(WARTHOG_MODULE_ROOT_ONLY ON CACHE BOOL "add submodule if present only allowed for root project")
+
+function(warthog_top_level)
+set(_is_top OFF)
+if(${CMAKE_VERSION} VERSION_GREATER_EQUAL 3.21)
+	if(${PROJECT_IS_TOP_LEVEL})
+		set(_is_top ON)
+	endif()
+else()
+	if(${CMAKE_SOURCE_DIR} STREQUAL ${PROJECT_SOURCE_DIR})
+		set(_is_top ON)
+	endif()
+endif()
+set(_warthog_is_top ${_is_top} PARENT_SCOPE)
+endfunction()
+
+# warthog_module module [override_top]
+# adds a module to warthog
+# has checks to insure module is only added once
+# if called from the top level project (or optional variable override_top is true)
+# then if extern/${module}/CMakeLists.txt exists, adds that version instead
+#    intended for use with git module/subtree.
+# otherwise, fetchcontent ${module} is made available
+# user must add FetchContent_Declare
+function(warthog_module module)
+get_property(_module_added GLOBAL PROPERTY WARTHOG_${module} SET)
+if(${_module_added}) # module already added
+	return()
+endif()
+if((${ARGC} GREATER 1) AND (${ARGV1}))
+	set(is_top_level ON)
+else()
+	warthog_top_level()
+	set(is_top_level ${_warthog_is_top})
+endif()
+if(${is_top_level})
+	if(EXISTS "${PROJECT_SOURCE_DIR}/extern/${module}/CMakeLists.txt")
+		# module or subtree, include and exit
+		add_subdirectory("${PROJECT_SOURCE_DIR}/extern/${module}")
+		set_property(GLOBAL PROPERTY WARTHOG_${module} ON)
+		return()
+	endif()
+endif()
+# failed to add module, fetch if able
+warthog_module_declare(${module})
+FetchContent_MakeAvailable(${module})
+set_property(GLOBAL PROPERTY WARTHOG_${module} ON)
+endfunction()
+
+function(warthog_module_declare module)
+if(NOT DEFINED warthog_https_${module})
+	return()
+endif()
+if((${ARGC} GREATER 1))
+	set(git_tag ${ARGV1})
+else()
+	set(git_tag "main")
+endif()
+FetchContent_Declare(${module}
+	GIT_REPOSITORY ${warthog_https_${module}}
+	GIT_TAG ${git_tag})
+endfunction()
diff --git a/extern/warthog-core b/extern/warthog-core
index deec8ce..f379ef2 160000
--- a/extern/warthog-core
+++ b/extern/warthog-core
@@ -1 +1 @@
-Subproject commit deec8ce4310b08196dc943a9fdbef9ccedfbafe2
+Subproject commit f379ef257335bb8bb6645c6efaeef031763273ea