diff --git a/Makefile b/Makefile
index d5ba0a4..cea7f45 100644
--- a/Makefile
+++ b/Makefile
@@ -1,19 +1,23 @@
-.PHONY: all clean test
+.PHONY: all build clean prepare-test test
 
 BUILD_DIR = ./build
+TMP_DIR = ./tmp
 APPS := $(notdir $(wildcard ./cmd/*))
 FLAGS := "-s -w"
 
-all:
+all: build
+
+build:
 	$(foreach APP,$(APPS), go build -ldflags=$(FLAGS) -o $(BUILD_DIR)/$(APP) ./cmd/$(APP);)
 
 clean:
 	rm -rf $(BUILD_DIR)/*
+	rm -rf $(TMP_DIR)/*
 	rm -rf *.out
 
 prepare-test:
 	git submodule update --init --remote
 
 test:
-	./scripts/prepare_test_repos.sh
+	./scripts/prepare_test_repos.sh $(TMP_DIR)
 	go test -coverprofile cover.out -v ./...
diff --git a/README.md b/README.md
index cbca578..296d0eb 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ $ go build -o ./tmp/go-judge ./cmd/go-judge
 5. Run `go-judge`.
 ```bash
 $ # make sure you are in go-judge directory
-$ ./tmp/go-judge -enable-grpc -enable-debug -enable-metrics
+$ ./tmp/go-judge -http-addr 0.0.0.0:5050 -grpc-addr 0.0.0.0:5051 -monitor-addr 0.0.0.0:5052 -enable-grpc -enable-debug -enable-metrics
 ```
 
 6. Pull submodules. It might be slow, so only run it when necessary.
diff --git a/cmd/joj3/conf.go b/cmd/joj3/conf.go
index 40dff6b..4f9951f 100644
--- a/cmd/joj3/conf.go
+++ b/cmd/joj3/conf.go
@@ -10,9 +10,11 @@ import (
 )
 
 type Conf struct {
-	LogLevel   int    `default:"0"`
-	OutputPath string `default:"joj3_result.json"`
-	Stages     []struct {
+	SandboxExecServer string `default:"localhost:5051"`
+	SandboxToken      string `default:""`
+	LogLevel          int    `default:"0"`
+	OutputPath        string `default:"joj3_result.json"`
+	Stages            []struct {
 		Name     string
 		Executor struct {
 			Name string
diff --git a/cmd/joj3/main.go b/cmd/joj3/main.go
index e21a52d..b8e0e05 100644
--- a/cmd/joj3/main.go
+++ b/cmd/joj3/main.go
@@ -5,7 +5,7 @@ import (
 	"log/slog"
 	"os"
 
-	_ "focs.ji.sjtu.edu.cn/git/FOCS-dev/JOJ3/internal/executors"
+	"focs.ji.sjtu.edu.cn/git/FOCS-dev/JOJ3/internal/executors"
 	_ "focs.ji.sjtu.edu.cn/git/FOCS-dev/JOJ3/internal/parsers"
 	"focs.ji.sjtu.edu.cn/git/FOCS-dev/JOJ3/internal/stage"
 
@@ -77,6 +77,7 @@ func main() {
 		os.Exit(1)
 	}
 	setupSlog(conf)
+	executors.InitWithConf(conf.SandboxExecServer, conf.SandboxToken)
 	stages := generateStages(conf)
 	defer stage.Cleanup()
 	results := stage.Run(stages)
diff --git a/cmd/joj3/main_test.go b/cmd/joj3/main_test.go
index daea3cf..1ea8029 100644
--- a/cmd/joj3/main_test.go
+++ b/cmd/joj3/main_test.go
@@ -66,7 +66,7 @@ func TestMain(t *testing.T) {
 	scoreboard := scoreboard.Scoreboard{}
 	scoreboard.Init()
 	var tests []string
-	root := "../../tmp/submodules/JOJ3-examples"
+	root := "../../tmp/submodules/JOJ3-examples/examples/"
 	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
 		if err != nil {
 			return err
diff --git a/internal/executors/all.go b/internal/executors/all.go
index bd860e6..76a7f96 100644
--- a/internal/executors/all.go
+++ b/internal/executors/all.go
@@ -2,8 +2,13 @@ package executors
 
 import (
 	_ "focs.ji.sjtu.edu.cn/git/FOCS-dev/JOJ3/internal/executors/dummy"
-	_ "focs.ji.sjtu.edu.cn/git/FOCS-dev/JOJ3/internal/executors/sandbox"
+	"focs.ji.sjtu.edu.cn/git/FOCS-dev/JOJ3/internal/executors/sandbox"
 )
 
 // this file does nothing but imports to ensure all the init() functions
 // in the subpackages are called
+
+// overwrite the default registered executors
+func InitWithConf(sandboxExecServer, sandboxToken string) {
+	sandbox.InitWithConf(sandboxExecServer, sandboxToken)
+}
diff --git a/internal/executors/sandbox/convert.go b/internal/executors/sandbox/convert.go
index e5b786f..827dd15 100644
--- a/internal/executors/sandbox/convert.go
+++ b/internal/executors/sandbox/convert.go
@@ -1,6 +1,7 @@
 package sandbox
 
 import (
+	"log/slog"
 	"os"
 	"path/filepath"
 	"strings"
@@ -113,7 +114,12 @@ func convertPBFile(i stage.CmdFile) *pb.Request_File {
 				i.Src = &absPath
 			}
 		}
-		return &pb.Request_File{File: &pb.Request_File_Local{Local: &pb.Request_LocalFile{Src: *i.Src}}}
+		s, err := os.ReadFile(*i.Src)
+		if err != nil {
+			s = []byte{}
+			slog.Error("read file error", "path", *i.Src, "error", err)
+		}
+		return &pb.Request_File{File: &pb.Request_File_Memory{Memory: &pb.Request_MemoryFile{Content: s}}}
 	case i.Content != nil:
 		s := strToBytes(*i.Content)
 		return &pb.Request_File{File: &pb.Request_File_Memory{Memory: &pb.Request_MemoryFile{Content: s}}}
diff --git a/internal/executors/sandbox/executor.go b/internal/executors/sandbox/executor.go
index 188c4b9..92c0eae 100644
--- a/internal/executors/sandbox/executor.go
+++ b/internal/executors/sandbox/executor.go
@@ -18,6 +18,7 @@ type Sandbox struct {
 func (e *Sandbox) Run(cmds []stage.Cmd) ([]stage.ExecutorResult, error) {
 	var err error
 	if e.execClient == nil {
+		slog.Debug("create exec client", "server", e.execServer)
 		e.execClient, err = createExecClient(e.execServer, e.token)
 		if err != nil {
 			return nil, err
diff --git a/internal/executors/sandbox/meta.go b/internal/executors/sandbox/meta.go
index 2702646..e984184 100644
--- a/internal/executors/sandbox/meta.go
+++ b/internal/executors/sandbox/meta.go
@@ -8,9 +8,17 @@ var name = "sandbox"
 
 func init() {
 	stage.RegisterExecutor(name, &Sandbox{
-		// TODO: read from conf
 		execServer: "localhost:5051",
 		token:      "",
 		cachedMap:  make(map[string]string),
 	})
 }
+
+// overwrite the default registered executor
+func InitWithConf(execServer, token string) {
+	stage.RegisterExecutor(name, &Sandbox{
+		execServer: execServer,
+		token:      token,
+		cachedMap:  make(map[string]string),
+	})
+}
diff --git a/scripts/prepare_test_repos.sh b/scripts/prepare_test_repos.sh
index fc877b4..21f0558 100755
--- a/scripts/prepare_test_repos.sh
+++ b/scripts/prepare_test_repos.sh
@@ -2,7 +2,7 @@
 
 set -ex
 declare -A repo_names
-tmp_dir="./tmp"
+tmp_dir=${1:-./tmp}
 submodules_dir="$tmp_dir/submodules"
 rm -rf $submodules_dir
 mkdir -p $submodules_dir
@@ -24,6 +24,7 @@ for submodule in $submodules; do
     repo_names[$repo_name]=1
     cd $repo_dir
     git checkout -q $branch
+    git reset -q --hard origin/$branch
     cd -
     submodule_dir="$submodules_dir/$repo_name/$submodule"
     mkdir -p $submodule_dir
diff --git a/scripts/run_foreach_test_repos.sh b/scripts/run_foreach_test_repos.sh
new file mode 100755
index 0000000..3c9ce55
--- /dev/null
+++ b/scripts/run_foreach_test_repos.sh
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+set -ex
+tmp_dir=${1:-./tmp}
+JOJ3=$(git rev-parse --show-toplevel)/build/joj3
+command=${2:-$JOJ3}
+submodules_dir="$tmp_dir/submodules"
+submodules=$(git config --file .gitmodules --get-regexp path | awk '{ print $2 }')
+for submodule in $submodules; do
+    url=$(git config --file .gitmodules --get-regexp "submodule.$submodule.url" | awk '{ print $2 }')
+    repo_name=$(echo $url | rev | cut -d'/' -f 1 | rev | cut -d'.' -f 1)
+    submodule_dir="$submodules_dir/$repo_name/$submodule"
+    cd $submodule_dir
+    eval "$command"
+    if [[ $command == $JOJ3 ]]; then
+        if [ -f "./expected.json" ]; then
+            mv -f "joj3_result.json" "expected.json"
+        fi
+    fi
+    cd -
+done