diff --git a/api.py b/api.py
old mode 100644
new mode 100755
index bcbd554..fc8766b
--- a/api.py
+++ b/api.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 from flask import Flask, request, jsonify
 import subprocess
 import json
@@ -73,4 +75,5 @@ def verify_payment():
 
 if __name__ == '__main__':
     debug_mode = os.getenv('APP_DEBUG', 'False').lower() in ('true', '1', 't')
-    app.run(debug=debug_mode)
+    port = int(os.getenv('PORT', 5000))
+    app.run(host='0.0.0.0', port=port, debug=debug_mode)