diff --git a/bin/joj3-forge-convert b/bin/joj3-forge-convert
index a7524cd..3728cc5 100755
--- a/bin/joj3-forge-convert
+++ b/bin/joj3-forge-convert
@@ -1,18 +1,43 @@
 #!/usr/bin/bash
 set -ex
-COURSE=$1
-REPO_PATH=/home/tt/.cache/$COURSE-config
-GIT_USER=$(whoami)
-GIT_HOSTNAME=$(hostname -s)
-GIT_EMAIL="${GIT_USER}@${GIT_HOSTNAME}"
-git -C $REPO_PATH pull --rebase
-rsync -r --delete $REPO_PATH/home/tt/.config/ /home/tt/.config
-joj3-forge convert /home/tt/.config/joj
-rsync -r --delete /home/tt/.config/joj/ $REPO_PATH/home/tt/.config/joj
-git -C $REPO_PATH config user.name $GIT_USER
-git -C $REPO_PATH config user.email $GIT_EMAIL
-git -C $REPO_PATH add home/tt/.config/joj
-if ! git -C "$REPO_PATH" diff --staged --quiet; then
-    git -C $REPO_PATH commit -m "chore: joj3-forge convert"
-    git -C $REPO_PATH push
+
+if [ -z "$1" ]; then
+  echo "error: course name is required" >&2
+  exit 1
+fi
+
+COURSE="$1"
+CONFIG_REPO_PATH="/home/tt/.cache/$COURSE-config"
+GRADING_REPO_PATH="/home/tt/.cache/$COURSE-joj"
+GIT_USER="bot-$COURSE"
+GIT_EMAIL="bot-$COURSE@focs.ji.sjtu.edu.cn"
+
+if ! [ -d "$CONFIG_REPO_PATH" ]; then
+    git clone "ssh://git@focs.ji.sjtu.edu.cn:2222/$COURSE/$COURSE-joj.git" "$CONFIG_REPO_PATH"
+fi
+# TODO: move this into if statement
+git -C "$CONFIG_REPO_PATH" config user.name "$GIT_USER"
+git -C "$CONFIG_REPO_PATH" config user.email "$GIT_EMAIL"
+
+if ! [ -d "$GRADING_REPO_PATH" ]; then
+    git clone "ssh://git@focs.ji.sjtu.edu.cn:2222/$COURSE/$COURSE-joj.git" "$GRADING_REPO_PATH"
+    git -C "$GRADING_REPO_PATH" switch --orphan grading
+    echo "# $COURSE JOJ grading" >"$GRADING_REPO_PATH/Readme.md"
+    echo "This branch is automatically updated by JOJ, **never edit any file in this branch!**" >>"$GRADING_REPO_PATH/Readme.md"
+    git -C "$GRADING_REPO_PATH" add Readme.md
+    git -C "$GRADING_REPO_PATH" commit -m"docs: readme"
+    git -C "$GRADING_REPO_PATH" push -u origin grading
+fi
+# TODO: move this into if statement
+git -C "$GRADING_REPO_PATH" config user.name "$GIT_USER"
+git -C "$GRADING_REPO_PATH" config user.email "$GIT_EMAIL"
+
+git -C "$CONFIG_REPO_PATH" pull --rebase
+rsync -r --delete "$CONFIG_REPO_PATH/home/tt/.config/" /home/tt/.config
+joj3-forge convert /home/tt/.config/joj
+rsync -r --delete /home/tt/.config/joj/ "$CONFIG_REPO_PATH/home/tt/.config/joj"
+git -C "$CONFIG_REPO_PATH" add home/tt/.config/joj
+if ! git -C "$CONFIG_REPO_PATH" diff --staged --quiet; then
+    git -C "$CONFIG_REPO_PATH" commit -m "chore: joj3-forge convert"
+    git -C "$CONFIG_REPO_PATH" push
 fi