diff --git a/authfs/tools/device-test.sh b/authfs/tools/device-test.sh
new file mode 100755
index 0000000..5cf5f10
--- /dev/null
+++ b/authfs/tools/device-test.sh
@@ -0,0 +1,60 @@
+#!/system/bin/sh
+
+# TODO(victorhsieh): Create a standard Android test for continuous integration.
+#
+# How to run this test:
+#
+# Setup:
+# $ adb push testdata/input.4m* /data/local/tmp
+#
+# Shell 1:
+# $ adb shell 'cd /data/local/tmp && exec 9</system/bin/sh 8<input.4m 7<input.4m.merkle_dump 6<input.4m.fsv_sig 5<input.4m 4<input.4m.merkle_dump.bad 3<input.4m.fsv_sig fd_server --ro-fds 9 --ro-fds 8:7:6 --ro-fds 5:4:3'
+#
+# Shell 2:
+# $ adb push tools/device-test.sh /data/local/tmp/ && adb shell /data/local/tmp/device-test.sh
+
+# Run with -u to enter new namespace.
+if [[ $1 == "-u" ]]; then
+  exec unshare -mUr $0
+fi
+
+cd /data/local/tmp
+
+MOUNTPOINT=/data/local/tmp/authfs
+trap "umount ${MOUNTPOINT}" EXIT;
+mkdir -p ${MOUNTPOINT}
+
+size=$(du -b /system/bin/sh |awk '{print $1}')
+size2=$(du -b input.4m |awk '{print $1}')
+
+echo "Mounting authfs in background ..."
+
+# TODO(170494765): Replace /dev/null (currently not used) with a valid
+# certificate.
+authfs \
+  ${MOUNTPOINT} \
+  --local-verified-file 2:input.4m:input.4m.merkle_dump:input.4m.fsv_sig:/dev/null \
+  --local-verified-file 3:input.4k1:input.4k1.merkle_dump:input.4k1.fsv_sig:/dev/null \
+  --local-verified-file 4:input.4k:input.4k.merkle_dump:input.4k.fsv_sig:/dev/null \
+  --local-unverified-file 5:/system/bin/sh \
+  --remote-unverified-file 6:9:${size} \
+  --remote-verified-file 7:8:${size2}:/dev/null \
+  --remote-verified-file 8:5:${size2}:/dev/null \
+  &
+sleep 0.1
+
+echo "Accessing files in authfs ..."
+md5sum ${MOUNTPOINT}/2 input.4m
+echo
+md5sum ${MOUNTPOINT}/3 input.4k1
+echo
+md5sum ${MOUNTPOINT}/4 input.4k
+echo
+md5sum ${MOUNTPOINT}/5 /system/bin/sh
+md5sum ${MOUNTPOINT}/6
+echo
+md5sum ${MOUNTPOINT}/7 input.4m
+echo
+echo Checking error cases...
+cat /data/local/tmp/authfs/8 2>&1 |grep -q ": I/O error" || echo "Failed to catch the problem"
+echo "Done!"