diff --git a/.gitignore b/.gitignore
index 80b530bbed..3d1b880101 100644
--- a/.gitignore
+++ b/.gitignore
@@ -185,6 +185,7 @@
 /git-whatchanged
 /git-worktree
 /git-write-tree
+/scalar
 /git-core-*/?*
 /git.res
 /gitweb/GITWEB-BUILD-OPTIONS
diff --git a/Documentation/Makefile b/Documentation/Makefile
index 849af6da30..12c533c1a3 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -21,6 +21,7 @@ MAN1_TXT += $(filter-out \
 MAN1_TXT += git.txt
 MAN1_TXT += gitk.txt
 MAN1_TXT += gitweb.txt
+MAN1_TXT += scalar.txt
 
 # man5 / man7 guides (note: new guides should also be added to command-list.txt)
 MAN5_TXT += gitattributes.txt
@@ -116,6 +117,7 @@ TECH_DOCS += technical/parallel-checkout
 TECH_DOCS += technical/partial-clone
 TECH_DOCS += technical/racy-git
 TECH_DOCS += technical/reftable
+TECH_DOCS += technical/scalar
 TECH_DOCS += technical/send-pack-pipeline
 TECH_DOCS += technical/shallow
 TECH_DOCS += technical/trivial-merge
diff --git a/Documentation/cmd-list.perl b/Documentation/cmd-list.perl
index af5da45d28..9515a499a3 100755
--- a/Documentation/cmd-list.perl
+++ b/Documentation/cmd-list.perl
@@ -10,7 +10,7 @@ sub format_one {
 	$state = 0;
 	open I, '<', "$name.txt" or die "No such file $name.txt";
 	while (<I>) {
-		if (/^git[a-z0-9-]*\(([0-9])\)$/) {
+		if (/^(git|scalar)[a-z0-9-]*\(([0-9])\)$/) {
 			$mansection = $1;
 			next;
 		}
diff --git a/contrib/scalar/scalar.txt b/Documentation/scalar.txt
similarity index 99%
rename from contrib/scalar/scalar.txt
rename to Documentation/scalar.txt
index 1a12dc4507..f33436c7f6 100644
--- a/contrib/scalar/scalar.txt
+++ b/Documentation/scalar.txt
@@ -161,6 +161,6 @@ SEE ALSO
 --------
 linkgit:git-clone[1], linkgit:git-maintenance[1].
 
-Scalar
+GIT
 ---
-Associated with the linkgit:git[1] suite
+Part of the linkgit:git[1] suite
diff --git a/Documentation/technical/scalar.txt b/Documentation/technical/scalar.txt
index 0600150b3a..921cb104c3 100644
--- a/Documentation/technical/scalar.txt
+++ b/Documentation/technical/scalar.txt
@@ -64,64 +64,3 @@ some "global" `git` options (e.g., `-c` and `-C`).
 Because `scalar` is not invoked as a Git subcommand (like `git scalar`), it is
 built and installed as its own executable in the `bin/` directory, alongside
 `git`, `git-gui`, etc.
-
-Roadmap
--------
-
-NOTE: this section will be removed once the remaining tasks outlined in this
-roadmap are complete.
-
-Scalar is a large enough project that it is being upstreamed incrementally,
-living in `contrib/` until it is feature-complete. So far, the following patch
-series have been accepted:
-
-- `scalar-the-beginning`: The initial patch series which sets up
-  `contrib/scalar/` and populates it with a minimal `scalar` command that
-  demonstrates the fundamental ideas.
-
-- `scalar-c-and-C`: The `scalar` command learns about two options that can be
-  specified before the command, `-c <key>=<value>` and `-C <directory>`.
-
-- `scalar-diagnose`: The `scalar` command is taught the `diagnose` subcommand.
-
-- `scalar-generalize-diagnose`: Move the functionality of `scalar diagnose`
-  into `git diagnose` and `git bugreport --diagnose`.
-
-- 'scalar-add-fsmonitor: Enable the built-in FSMonitor in Scalar
-  enlistments. At the end of this series, Scalar should be feature-complete
-  from the perspective of a user.
-
-Roughly speaking (and subject to change), the following series are needed to
-"finish" this initial version of Scalar:
-
-- Move Scalar to toplevel: Move Scalar out of `contrib/` and into the root of
-  `git`. This includes a variety of related updates, including:
-    - building & installing Scalar in the Git root-level 'make [install]'.
-    - builing & testing Scalar as part of CI.
-    - moving and expanding test coverage of Scalar (including perf tests).
-    - implementing 'scalar help'/'git help scalar' to display scalar
-      documentation.
-
-Finally, there are two additional patch series that exist in Microsoft's fork of
-Git, but there is no current plan to upstream them. There are some interesting
-ideas there, but the implementation is too specific to Azure Repos and/or VFS
-for Git to be of much help in general.
-
-These still exist mainly because the GVFS protocol is what Azure Repos has
-instead of partial clone, while Git is focused on improving partial clone:
-
-- `scalar-with-gvfs`: The primary purpose of this patch series is to support
-  existing Scalar users whose repositories are hosted in Azure Repos (which does
-  not support Git's partial clones, but supports its predecessor, the GVFS
-  protocol, which is used by Scalar to emulate the partial clone).
-
-  Since the GVFS protocol will never be supported by core Git, this patch series
-  will remain in Microsoft's fork of Git.
-
-- `run-scalar-functional-tests`: The Scalar project developed a quite
-  comprehensive set of integration tests (or, "Functional Tests"). They are the
-  sole remaining part of the original C#-based Scalar project, and this patch
-  adds a GitHub workflow that runs them all.
-
-  Since the tests partially depend on features that are only provided in the
-  `scalar-with-gvfs` patch series, this patch cannot be upstreamed.
diff --git a/Makefile b/Makefile
index d9247ead45..35a07f80c5 100644
--- a/Makefile
+++ b/Makefile
@@ -605,7 +605,9 @@ FUZZ_OBJS =
 FUZZ_PROGRAMS =
 GIT_OBJS =
 LIB_OBJS =
+SCALAR_OBJS =
 OBJECTS =
+OTHER_PROGRAMS =
 PROGRAM_OBJS =
 PROGRAMS =
 EXCLUDED_PROGRAMS =
@@ -819,10 +821,12 @@ BUILT_INS += git-switch$X
 BUILT_INS += git-whatchanged$X
 
 # what 'all' will build but not install in gitexecdir
-OTHER_PROGRAMS = git$X
+OTHER_PROGRAMS += git$X
+OTHER_PROGRAMS += scalar$X
 
 # what test wrappers are needed and 'install' will install, in bindir
 BINDIR_PROGRAMS_NEED_X += git
+BINDIR_PROGRAMS_NEED_X += scalar
 BINDIR_PROGRAMS_NEED_X += git-receive-pack
 BINDIR_PROGRAMS_NEED_X += git-shell
 BINDIR_PROGRAMS_NEED_X += git-upload-archive
@@ -2220,7 +2224,7 @@ profile-fast: profile-clean
 
 all:: $(ALL_COMMANDS_TO_INSTALL) $(SCRIPT_LIB) $(OTHER_PROGRAMS) GIT-BUILD-OPTIONS
 ifneq (,$X)
-	$(QUIET_BUILT_IN)$(foreach p,$(patsubst %$X,%,$(filter %$X,$(ALL_COMMANDS_TO_INSTALL) git$X)), test -d '$p' -o '$p' -ef '$p$X' || $(RM) '$p';)
+	$(QUIET_BUILT_IN)$(foreach p,$(patsubst %$X,%,$(filter %$X,$(ALL_COMMANDS_TO_INSTALL) $(OTHER_PROGRAMS))), test -d '$p' -o '$p' -ef '$p$X' || $(RM) '$p';)
 endif
 
 all::
@@ -2543,7 +2547,12 @@ GIT_OBJS += git.o
 .PHONY: git-objs
 git-objs: $(GIT_OBJS)
 
+SCALAR_OBJS += scalar.o
+.PHONY: scalar-objs
+scalar-objs: $(SCALAR_OBJS)
+
 OBJECTS += $(GIT_OBJS)
+OBJECTS += $(SCALAR_OBJS)
 OBJECTS += $(PROGRAM_OBJS)
 OBJECTS += $(TEST_OBJS)
 OBJECTS += $(XDIFF_OBJS)
@@ -2554,10 +2563,6 @@ ifndef NO_CURL
 	OBJECTS += http.o http-walker.o remote-curl.o
 endif
 
-SCALAR_SOURCES := contrib/scalar/scalar.c
-SCALAR_OBJECTS := $(SCALAR_SOURCES:c=o)
-OBJECTS += $(SCALAR_OBJECTS)
-
 .PHONY: objects
 objects: $(OBJECTS)
 
@@ -2683,7 +2688,7 @@ $(REMOTE_CURL_PRIMARY): remote-curl.o http.o http-walker.o GIT-LDFLAGS $(GITLIBS
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
 		$(CURL_LIBCURL) $(EXPAT_LIBEXPAT) $(LIBS)
 
-contrib/scalar/scalar$X: $(SCALAR_OBJECTS) GIT-LDFLAGS $(GITLIBS)
+scalar$X: scalar.o GIT-LDFLAGS $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) \
 		$(filter %.o,$^) $(LIBS)
 
@@ -2739,8 +2744,7 @@ XGETTEXT_FLAGS_SH = $(XGETTEXT_FLAGS) --language=Shell \
 XGETTEXT_FLAGS_PERL = $(XGETTEXT_FLAGS) --language=Perl \
 	--keyword=__ --keyword=N__ --keyword="__n:1,2"
 MSGMERGE_FLAGS = --add-location --backup=off --update
-LOCALIZED_C = $(sort $(FOUND_C_SOURCES) $(FOUND_H_SOURCES) $(SCALAR_SOURCES) \
-	        $(GENERATED_H))
+LOCALIZED_C = $(sort $(FOUND_C_SOURCES) $(FOUND_H_SOURCES) $(GENERATED_H))
 LOCALIZED_SH = $(sort $(SCRIPT_SH) git-sh-setup.sh)
 LOCALIZED_PERL = $(sort $(SCRIPT_PERL))
 
@@ -3054,7 +3058,7 @@ bin-wrappers/%: wrap-for-bin.sh
 	$(call mkdir_p_parent_template)
 	$(QUIET_GEN)sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
 	     -e 's|@@BUILD_DIR@@|$(shell pwd)|' \
-	     -e 's|@@PROG@@|$(patsubst test-%,t/helper/test-%$(X),$(@F))$(patsubst git%,$(X),$(filter $(@F),$(BINDIR_PROGRAMS_NEED_X)))|' < $< > $@ && \
+	     -e 's|@@PROG@@|$(patsubst test-%,t/helper/test-%,$(@F))$(if $(filter-out $(BINDIR_PROGRAMS_NO_X),$(@F)),$(X),)|' < $< > $@ && \
 	chmod +x $@
 
 # GNU make supports exporting all variables by "export" without parameters.
@@ -3268,14 +3272,14 @@ ifndef NO_TCLTK
 	$(MAKE) -C git-gui gitexecdir='$(gitexec_instdir_SQ)' install
 endif
 ifneq (,$X)
-	$(foreach p,$(patsubst %$X,%,$(filter %$X,$(ALL_COMMANDS_TO_INSTALL) git$X)), test '$(DESTDIR_SQ)$(gitexec_instdir_SQ)/$p' -ef '$(DESTDIR_SQ)$(gitexec_instdir_SQ)/$p$X' || $(RM) '$(DESTDIR_SQ)$(gitexec_instdir_SQ)/$p';)
+	$(foreach p,$(patsubst %$X,%,$(filter %$X,$(ALL_COMMANDS_TO_INSTALL) $(OTHER_PROGRAMS))), test '$(DESTDIR_SQ)$(gitexec_instdir_SQ)/$p' -ef '$(DESTDIR_SQ)$(gitexec_instdir_SQ)/$p$X' || $(RM) '$(DESTDIR_SQ)$(gitexec_instdir_SQ)/$p';)
 endif
 
 	bindir=$$(cd '$(DESTDIR_SQ)$(bindir_SQ)' && pwd) && \
 	execdir=$$(cd '$(DESTDIR_SQ)$(gitexec_instdir_SQ)' && pwd) && \
 	destdir_from_execdir_SQ=$$(echo '$(gitexecdir_relative_SQ)' | sed -e 's|[^/][^/]*|..|g') && \
 	{ test "$$bindir/" = "$$execdir/" || \
-	  for p in git$X $(filter $(install_bindir_programs),$(ALL_PROGRAMS)); do \
+	  for p in $(OTHER_PROGRAMS) $(filter $(install_bindir_programs),$(ALL_PROGRAMS)); do \
 		$(RM) "$$execdir/$$p" && \
 		test -n "$(INSTALL_SYMLINKS)" && \
 		ln -s "$$destdir_from_execdir_SQ/$(bindir_relative_SQ)/$$p" "$$execdir/$$p" || \
@@ -3450,7 +3454,7 @@ clean: profile-clean coverage-clean cocciclean
 	$(RM) git.res
 	$(RM) $(OBJECTS)
 	$(RM) $(LIB_FILE) $(XDIFF_LIB) $(REFTABLE_LIB) $(REFTABLE_TEST_LIB)
-	$(RM) $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) git$X
+	$(RM) $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) $(OTHER_PROGRAMS)
 	$(RM) $(TEST_PROGRAMS)
 	$(RM) $(FUZZ_PROGRAMS)
 	$(RM) $(SP_OBJ)
@@ -3501,6 +3505,7 @@ ALL_COMMANDS += git-citool
 ALL_COMMANDS += git-gui
 ALL_COMMANDS += gitk
 ALL_COMMANDS += gitweb
+ALL_COMMANDS += scalar
 
 .PHONY: check-docs
 check-docs::
diff --git a/builtin/help.c b/builtin/help.c
index 09ac4289f1..6f2796f211 100644
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -440,6 +440,8 @@ static const char *cmd_to_page(const char *git_cmd)
 		return git_cmd;
 	else if (is_git_command(git_cmd))
 		return xstrfmt("git-%s", git_cmd);
+	else if (!strcmp("scalar", git_cmd))
+		return xstrdup(git_cmd);
 	else
 		return xstrfmt("git%s", git_cmd);
 }
diff --git a/command-list.txt b/command-list.txt
index f96bdabd7d..93f94e42ab 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -235,3 +235,4 @@ gittutorial                             guide
 gittutorial-2                           guide
 gitweb                                  ancillaryinterrogators
 gitworkflows                            guide
+scalar                                  mainporcelain
diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index ca358a21a5..ea2a531be8 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -610,7 +610,7 @@ unset(CMAKE_REQUIRED_INCLUDES)
 #programs
 set(PROGRAMS_BUILT
 	git git-daemon git-http-backend git-sh-i18n--envsubst
-	git-shell)
+	git-shell scalar)
 
 if(NOT CURL_FOUND)
 	list(APPEND excluded_progs git-http-fetch git-http-push)
@@ -757,6 +757,9 @@ target_link_libraries(git-sh-i18n--envsubst common-main)
 add_executable(git-shell ${CMAKE_SOURCE_DIR}/shell.c)
 target_link_libraries(git-shell common-main)
 
+add_executable(scalar ${CMAKE_SOURCE_DIR}/scalar.c)
+target_link_libraries(scalar common-main)
+
 if(CURL_FOUND)
 	add_library(http_obj OBJECT ${CMAKE_SOURCE_DIR}/http.c)
 
@@ -903,7 +906,7 @@ list(TRANSFORM git_perl_scripts PREPEND "${CMAKE_BINARY_DIR}/")
 
 #install
 foreach(program ${PROGRAMS_BUILT})
-if(program STREQUAL "git" OR program STREQUAL "git-shell")
+if(program MATCHES "^(git|git-shell|scalar)$")
 install(TARGETS ${program}
 	RUNTIME DESTINATION bin)
 else()
@@ -977,7 +980,7 @@ endif()
 
 #wrapper scripts
 set(wrapper_scripts
-	git git-upload-pack git-receive-pack git-upload-archive git-shell git-remote-ext)
+	git git-upload-pack git-receive-pack git-upload-archive git-shell git-remote-ext scalar)
 
 set(wrapper_test_scripts
 	test-fake-ssh test-tool)
diff --git a/contrib/scalar/.gitignore b/contrib/scalar/.gitignore
deleted file mode 100644
index ff3d47e84d..0000000000
--- a/contrib/scalar/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-/*.exe
-/scalar
diff --git a/contrib/scalar/Makefile b/contrib/scalar/Makefile
deleted file mode 100644
index 37f283f35d..0000000000
--- a/contrib/scalar/Makefile
+++ /dev/null
@@ -1,35 +0,0 @@
-# The default target of this Makefile is...
-all::
-
-# Import tree-wide shared Makefile behavior and libraries
-include ../../shared.mak
-
-include ../../config.mak.uname
--include ../../config.mak.autogen
--include ../../config.mak
-
-TARGETS = scalar$(X) scalar.o
-GITLIBS = ../../common-main.o ../../libgit.a ../../xdiff/lib.a
-
-all:: scalar$(X) ../../bin-wrappers/scalar
-
-$(GITLIBS):
-	$(QUIET_SUBDIR0)../.. $(QUIET_SUBDIR1) $(subst ../../,,$@)
-
-$(TARGETS): $(GITLIBS) scalar.c
-	$(QUIET_SUBDIR0)../.. $(QUIET_SUBDIR1) $(patsubst %,contrib/scalar/%,$@)
-
-clean:
-	$(RM) $(TARGETS) ../../bin-wrappers/scalar
-
-../../bin-wrappers/scalar: ../../wrap-for-bin.sh Makefile
-	@mkdir -p ../../bin-wrappers
-	$(QUIET_GEN)sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
-	     -e 's|@@BUILD_DIR@@|$(shell cd ../.. && pwd)|' \
-	     -e 's|@@PROG@@|contrib/scalar/scalar$(X)|' < $< > $@ && \
-	chmod +x $@
-
-test: all
-	$(MAKE) -C t
-
-.PHONY: $(GITLIBS) all clean test FORCE
diff --git a/contrib/scalar/t/Makefile b/contrib/scalar/t/Makefile
deleted file mode 100644
index 1ed174a8cf..0000000000
--- a/contrib/scalar/t/Makefile
+++ /dev/null
@@ -1,81 +0,0 @@
-# Import tree-wide shared Makefile behavior and libraries
-include ../../../shared.mak
-
-# Run scalar tests
-#
-# Copyright (c) 2005,2021 Junio C Hamano, Johannes Schindelin
-#
-
--include ../../../config.mak.autogen
--include ../../../config.mak
-
-SHELL_PATH ?= $(SHELL)
-PERL_PATH ?= /usr/bin/perl
-RM ?= rm -f
-PROVE ?= prove
-DEFAULT_TEST_TARGET ?= test
-TEST_LINT ?= test-lint
-
-ifdef TEST_OUTPUT_DIRECTORY
-TEST_RESULTS_DIRECTORY = $(TEST_OUTPUT_DIRECTORY)/test-results
-else
-TEST_RESULTS_DIRECTORY = ../../../t/test-results
-endif
-
-# Shell quote;
-SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
-PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
-TEST_RESULTS_DIRECTORY_SQ = $(subst ','\'',$(TEST_RESULTS_DIRECTORY))
-
-T = $(sort $(wildcard t[0-9][0-9][0-9][0-9]-*.sh))
-
-all: $(DEFAULT_TEST_TARGET)
-
-test: $(TEST_LINT)
-	$(MAKE) aggregate-results-and-cleanup
-
-prove: $(TEST_LINT)
-	@echo "*** prove ***"; GIT_CONFIG=.git/config $(PROVE) --exec '$(SHELL_PATH_SQ)' $(GIT_PROVE_OPTS) $(T) :: $(GIT_TEST_OPTS)
-	$(MAKE) clean-except-prove-cache
-
-$(T):
-	@echo "*** $@ ***"; GIT_CONFIG=.git/config '$(SHELL_PATH_SQ)' $@ $(GIT_TEST_OPTS)
-
-clean-except-prove-cache:
-	$(RM) -r 'trash directory'.*
-	$(RM) -r valgrind/bin
-
-clean: clean-except-prove-cache
-	$(RM) .prove
-
-test-lint: test-lint-duplicates test-lint-executable test-lint-shell-syntax
-
-test-lint-duplicates:
-	@dups=`echo $(T) | tr ' ' '\n' | sed 's/-.*//' | sort | uniq -d` && \
-		test -z "$$dups" || { \
-		echo >&2 "duplicate test numbers:" $$dups; exit 1; }
-
-test-lint-executable:
-	@bad=`for i in $(T); do test -x "$$i" || echo $$i; done` && \
-		test -z "$$bad" || { \
-		echo >&2 "non-executable tests:" $$bad; exit 1; }
-
-test-lint-shell-syntax:
-	@'$(PERL_PATH_SQ)' ../../../t/check-non-portable-shell.pl $(T)
-
-aggregate-results-and-cleanup: $(T)
-	$(MAKE) aggregate-results
-	$(MAKE) clean
-
-aggregate-results:
-	for f in '$(TEST_RESULTS_DIRECTORY_SQ)'/t*-*.counts; do \
-		echo "$$f"; \
-	done | '$(SHELL_PATH_SQ)' ../../../t/aggregate-results.sh
-
-valgrind:
-	$(MAKE) GIT_TEST_OPTS="$(GIT_TEST_OPTS) --valgrind"
-
-test-results:
-	mkdir -p test-results
-
-.PHONY: $(T) aggregate-results clean valgrind
diff --git a/contrib/scalar/scalar.c b/scalar.c
similarity index 98%
rename from contrib/scalar/scalar.c
rename to scalar.c
index 642d16124e..c5c1ce6891 100644
--- a/contrib/scalar/scalar.c
+++ b/scalar.c
@@ -819,6 +819,25 @@ static int cmd_delete(int argc, const char **argv)
 	return res;
 }
 
+static int cmd_help(int argc, const char **argv)
+{
+	struct option options[] = {
+		OPT_END(),
+	};
+	const char * const usage[] = {
+		"scalar help",
+		NULL
+	};
+
+	argc = parse_options(argc, argv, NULL, options,
+			     usage, 0);
+
+	if (argc != 0)
+		usage_with_options(usage, options);
+
+	return run_git("help", "scalar", NULL);
+}
+
 static int cmd_version(int argc, const char **argv)
 {
 	int verbose = 0, build_options = 0;
@@ -858,6 +877,7 @@ static struct {
 	{ "run", cmd_run },
 	{ "reconfigure", cmd_reconfigure },
 	{ "delete", cmd_delete },
+	{ "help", cmd_help },
 	{ "version", cmd_version },
 	{ "diagnose", cmd_diagnose },
 	{ NULL, NULL},
diff --git a/t/perf/README b/t/perf/README
index fb9127a66f..8f217d7be7 100644
--- a/t/perf/README
+++ b/t/perf/README
@@ -95,6 +95,10 @@ You can set the following variables (also in your config.mak):
 	Git (e.g., performance of index-pack as the number of threads
 	changes). These can be enabled with GIT_PERF_EXTRA.
 
+    GIT_PERF_USE_SCALAR
+	Boolean indicating whether to register test repo(s) with Scalar
+	before executing tests.
+
 You can also pass the options taken by ordinary git tests; the most
 useful one is:
 
diff --git a/t/perf/p9210-scalar.sh b/t/perf/p9210-scalar.sh
new file mode 100755
index 0000000000..265f7cd1fe
--- /dev/null
+++ b/t/perf/p9210-scalar.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+
+test_description='test scalar performance'
+. ./perf-lib.sh
+
+test_perf_large_repo "$TRASH_DIRECTORY/to-clone"
+
+test_expect_success 'enable server-side partial clone' '
+	git -C to-clone config uploadpack.allowFilter true &&
+	git -C to-clone config uploadpack.allowAnySHA1InWant true
+'
+
+test_perf 'scalar clone' '
+	rm -rf scalar-clone &&
+	scalar clone "file://$(pwd)/to-clone" scalar-clone
+'
+
+test_perf 'git clone' '
+	rm -rf git-clone &&
+	git clone "file://$(pwd)/to-clone" git-clone
+'
+
+test_compare_perf () {
+	command=$1
+	shift
+	args=$*
+	test_perf "$command $args (scalar)" "
+		$command -C scalar-clone/src $args
+	"
+
+	test_perf "$command $args (non-scalar)" "
+		$command -C git-clone $args
+	"
+}
+
+test_compare_perf git status
+test_compare_perf test_commit --append --no-tag A
+
+test_done
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index 27c2801792..e7786775a9 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -49,6 +49,9 @@ export TEST_DIRECTORY TRASH_DIRECTORY GIT_BUILD_DIR GIT_TEST_CMP
 MODERN_GIT=$GIT_BUILD_DIR/bin-wrappers/git
 export MODERN_GIT
 
+MODERN_SCALAR=$GIT_BUILD_DIR/bin-wrappers/scalar
+export MODERN_SCALAR
+
 perf_results_dir=$TEST_RESULTS_DIR
 test -n "$GIT_PERF_SUBSECTION" && perf_results_dir="$perf_results_dir/$GIT_PERF_SUBSECTION"
 mkdir -p "$perf_results_dir"
@@ -120,6 +123,10 @@ test_perf_create_repo_from () {
 			# status" due to a locked index. Since we have
 			# a copy it's fine to remove the lock.
 			rm .git/index.lock
+		fi &&
+		if test_bool_env GIT_PERF_USE_SCALAR false
+		then
+			"$MODERN_SCALAR" register
 		fi
 	) || error "failed to copy repository '$source' to '$repo'"
 }
@@ -130,7 +137,11 @@ test_perf_fresh_repo () {
 	"$MODERN_GIT" init -q "$repo" &&
 	(
 		cd "$repo" &&
-		test_perf_do_repo_symlink_config_
+		test_perf_do_repo_symlink_config_ &&
+		if test_bool_env GIT_PERF_USE_SCALAR false
+		then
+			"$MODERN_SCALAR" register
+		fi
 	)
 }
 
diff --git a/t/perf/run b/t/perf/run
index 55219aa405..33da4d2aba 100755
--- a/t/perf/run
+++ b/t/perf/run
@@ -171,6 +171,9 @@ run_subsection () {
 	get_var_from_env_or_config "GIT_PERF_MAKE_COMMAND" "perf" "makeCommand"
 	get_var_from_env_or_config "GIT_PERF_MAKE_OPTS" "perf" "makeOpts"
 
+	get_var_from_env_or_config "GIT_PERF_USE_SCALAR" "perf" "useScalar" "--bool"
+	export GIT_PERF_USE_SCALAR
+
 	get_var_from_env_or_config "GIT_PERF_REPO_NAME" "perf" "repoName"
 	export GIT_PERF_REPO_NAME
 
diff --git a/contrib/scalar/t/t9099-scalar.sh b/t/t9210-scalar.sh
similarity index 96%
rename from contrib/scalar/t/t9099-scalar.sh
rename to t/t9210-scalar.sh
index dfb949f52e..14ca575a21 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/t/t9210-scalar.sh
@@ -2,15 +2,9 @@
 
 test_description='test the `scalar` command'
 
-TEST_DIRECTORY=$PWD/../../../t
-export TEST_DIRECTORY
+. ./test-lib.sh
 
-# Make it work with --no-bin-wrappers
-PATH=$PWD/..:$PATH
-
-. ../../../t/test-lib.sh
-
-GIT_TEST_MAINT_SCHEDULER="crontab:test-tool crontab ../cron.txt,launchctl:true,schtasks:true"
+GIT_TEST_MAINT_SCHEDULER="crontab:test-tool crontab cron.txt,launchctl:true,schtasks:true"
 export GIT_TEST_MAINT_SCHEDULER
 
 test_expect_success 'scalar shows a usage' '
diff --git a/t/t9211-scalar-clone.sh b/t/t9211-scalar-clone.sh
new file mode 100755
index 0000000000..dd33d87e9b
--- /dev/null
+++ b/t/t9211-scalar-clone.sh
@@ -0,0 +1,151 @@
+#!/bin/sh
+
+test_description='test the `scalar clone` subcommand'
+
+. ./test-lib.sh
+
+GIT_TEST_MAINT_SCHEDULER="crontab:test-tool crontab cron.txt,launchctl:true,schtasks:true"
+export GIT_TEST_MAINT_SCHEDULER
+
+test_expect_success 'set up repository to clone' '
+	rm -rf .git &&
+	git init to-clone &&
+	(
+		cd to-clone &&
+		git branch -m base &&
+
+		test_commit first &&
+		test_commit second &&
+		test_commit third &&
+
+		git switch -c parallel first &&
+		mkdir -p 1/2 &&
+		test_commit 1/2/3 &&
+
+		git switch base &&
+
+		# By default, permit
+		git config uploadpack.allowfilter true &&
+		git config uploadpack.allowanysha1inwant true
+	)
+'
+
+cleanup_clone () {
+	rm -rf "$1"
+}
+
+test_expect_success 'creates content in enlistment root' '
+	enlistment=cloned &&
+
+	scalar clone "file://$(pwd)/to-clone" $enlistment &&
+	ls -A $enlistment >enlistment-root &&
+	test_line_count = 1 enlistment-root &&
+	test_path_is_dir $enlistment/src &&
+	test_path_is_dir $enlistment/src/.git &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success 'with spaces' '
+	enlistment="cloned with space" &&
+
+	scalar clone "file://$(pwd)/to-clone" "$enlistment" &&
+	test_path_is_dir "$enlistment" &&
+	test_path_is_dir "$enlistment/src" &&
+	test_path_is_dir "$enlistment/src/.git" &&
+
+	cleanup_clone "$enlistment"
+'
+
+test_expect_success 'partial clone if supported by server' '
+	enlistment=partial-clone &&
+
+	scalar clone "file://$(pwd)/to-clone" $enlistment &&
+
+	(
+		cd $enlistment/src &&
+
+		# Two promisor packs: one for refs, the other for blobs
+		ls .git/objects/pack/pack-*.promisor >promisorlist &&
+		test_line_count = 2 promisorlist
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success 'fall back on full clone if partial unsupported' '
+	enlistment=no-partial-support &&
+
+	test_config -C to-clone uploadpack.allowfilter false &&
+	test_config -C to-clone uploadpack.allowanysha1inwant false &&
+
+	scalar clone "file://$(pwd)/to-clone" $enlistment 2>err &&
+	grep "filtering not recognized by server, ignoring" err &&
+
+	(
+		cd $enlistment/src &&
+
+		# Still get a refs promisor file, but none for blobs
+		ls .git/objects/pack/pack-*.promisor >promisorlist &&
+		test_line_count = 1 promisorlist
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success 'initializes sparse-checkout by default' '
+	enlistment=sparse &&
+
+	scalar clone "file://$(pwd)/to-clone" $enlistment &&
+	(
+		cd $enlistment/src &&
+		test_cmp_config true core.sparseCheckout &&
+		test_cmp_config true core.sparseCheckoutCone
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success '--full-clone does not create sparse-checkout' '
+	enlistment=full-clone &&
+
+	scalar clone --full-clone "file://$(pwd)/to-clone" $enlistment &&
+	(
+		cd $enlistment/src &&
+		test_cmp_config "" --default "" core.sparseCheckout &&
+		test_cmp_config "" --default "" core.sparseCheckoutCone
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success '--single-branch clones HEAD only' '
+	enlistment=single-branch &&
+
+	scalar clone --single-branch "file://$(pwd)/to-clone" $enlistment &&
+	(
+		cd $enlistment/src &&
+		git for-each-ref refs/remotes/origin >out &&
+		test_line_count = 1 out &&
+		grep "refs/remotes/origin/base" out
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success '--no-single-branch clones all branches' '
+	enlistment=no-single-branch &&
+
+	scalar clone --no-single-branch "file://$(pwd)/to-clone" $enlistment &&
+	(
+		cd $enlistment/src &&
+		git for-each-ref refs/remotes/origin >out &&
+		test_line_count = 2 out &&
+		grep "refs/remotes/origin/base" out &&
+		grep "refs/remotes/origin/parallel" out
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_done