diff --git a/.githooks/post-checkout b/.githooks/post-checkout
new file mode 100755
index 0000000..a381e6c
--- /dev/null
+++ b/.githooks/post-checkout
@@ -0,0 +1,54 @@
+#!/bin/bash -
+# echo "POST-CHECKOUT"
+# echo "PREV-HEAD=$1"
+# echo "CURR-HEAD=$2"
+# echo "BRANCH-CHECKOUT=$3"
+
+readonly CHECKOUT_HISTORY_FILE="/opt/app/tools/atbupdate/checkout_history"
+readonly GIT_UPDATE_LOG="/opt/app/tools/atbupdate/update_log.csv"
+readonly OPKG_COMMANDS_FILE="/etc/psa_update/opkg_commands"
+
+write_log_file () {
+    if [ -f $CHECKOUT_HISTORY_FILE ]; then
+        # repo: customer_281
+        readonly repo=$(basename $(git rev-parse --show-toplevel))
+        # branch: customer_281:HEAD->zg1/zone1,origin/zg1/zone1 
+        readonly branch=$(git log --graph --all --decorate $2 | head -n 1 | sed -E -e 's/(.*?)\((.*)\)/\2/g' | sed -E -e s/[[:space:]]//g)
+        readonly line="$repo:$branch"
+        readonly now="$(date +%Y-%m-%dT%T)"
+        if ! grep -Eq "$line" $CHECKOUT_HISTORY_FILE; then
+            # line not found. first checkout of this branch (on this PSA).
+            # mark dc and print-templates to be downloaded by update-tool.
+            echo "DOWNLOAD, /etc/dc/dc2c.bin, $now, N/A" >> $GIT_UPDATE_LOG
+            echo "DOWNLOAD, /etc/psa_config/DC2C_print01.json, $now, N/A" >> $GIT_UPDATE_LOG
+            echo "DOWNLOAD, /etc/psa_config/DC2C_print02.json, $now, N/A" >> $GIT_UPDATE_LOG
+            echo "DOWNLOAD, /etc/psa_config/DC2C_print03.json, $now, N/A" >> $GIT_UPDATE_LOG
+            echo "DOWNLOAD, /etc/psa_config/DC2C_print04.json, $now, N/A" >> $GIT_UPDATE_LOG
+            echo "DOWNLOAD, /etc/psa_config/DC2C_print29.json, $now, N/A" >> $GIT_UPDATE_LOG
+            echo "DOWNLOAD, /etc/psa_config/DC2C_print32.json, $now, N/A" >> $GIT_UPDATE_LOG
+            if grep -qE . "${OPKG_COMMANDS_FILE}"; then
+                readarray opkg_commands < <(cat $OPKG_COMMANDS_FILE)
+                for opkg_c in "${opkg_commands[@]}"; do
+                    # check for lines longer than 'opkg '
+                    if [ "${#opkg_c}" -gt 4 ]; then
+                        # comment: spaces, at least one '#'
+                        grep -qE '^[[:space:]]*#+.*$' <<< "$opkg_c" && continue
+                        echo -n "EXECUTE, $opkg_c, $now, N/A" | tr -d '\n\r' >> $GIT_UPDATE_LOG 2>&1
+                        echo "" >> $GIT_UPDATE_LOG 2>&1
+                    fi
+                done
+            fi
+        else
+            echo "Found existing line: $line. Do nothing"
+        fi
+        echo "$line" >> $CHECKOUT_HISTORY_FILE
+        # echo "$line @$now" >> $CHECKOUT_HISTORY_FILE
+    else
+        echo "*******************************************************"
+        echo "     $CHECKOUT_HISTORY_FILE DOES NOT EXIST !!!         "
+        echo "*******************************************************"
+    fi
+}
+
+write_log_file
+