diff --git a/management/daemon.py b/management/daemon.py
index 3c19367b..a0cfefa6 100755
--- a/management/daemon.py
+++ b/management/daemon.py
@@ -1,4 +1,11 @@
 #!/usr/local/lib/mailinabox/env/bin/python3
+#
+# During development, you can start the Mail-in-a-Box control panel
+# by running this script, e.g.:
+#
+# service mailinabox stop # stop the system process
+# DEBUG=1 management/daemon.py
+# service mailinabox start # when done debugging, start it up again
 
 import os, os.path, re, json, time
 import multiprocessing.pool, subprocess
@@ -680,7 +687,22 @@ def log_failed_login(request):
 # APP
 
 if __name__ == '__main__':
-	if "DEBUG" in os.environ: app.debug = True
+	if "DEBUG" in os.environ:
+		# Turn on Flask debugging.
+		app.debug = True
+
+		# Use a stable-ish master API key so that login sessions don't restart on each run.
+		# Use /etc/machine-id to seed the key with a stable secret, but add something
+		# and hash it to prevent possibly exposing the machine id, using the time so that
+		# the key is not valid indefinitely.
+		import hashlib
+		with open("/etc/machine-id") as f:
+			api_key = f.read()
+		api_key += "|" + str(int(time.time() / (60*60*2)))
+		hasher = hashlib.sha1()
+		hasher.update(api_key.encode("ascii"))
+		auth_service.key = hasher.hexdigest()
+
 	if "APIKEY" in os.environ: auth_service.key = os.environ["APIKEY"]
 
 	if not app.debug: