diff --git a/Dockerfile b/Dockerfile
index ba932d1..69017c6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,5 +14,5 @@ RUN pip install --no-cache-dir praw
 
 ENV PYTHONUNBUFFERED=1
 
-# Run the script
-CMD ["python", "Bot/main.py"]
+# Always generate config.py from environment before starting
+CMD ["/bin/sh", "-c", "python populate_config.py && python Bot/main.py"]
diff --git a/populate_config.py b/populate_config.py
new file mode 100644
index 0000000..d2f964c
--- /dev/null
+++ b/populate_config.py
@@ -0,0 +1,52 @@
+import os
+import json
+
+CONFIG_KEYS = [
+    "client_id",
+    "client_secret",
+    "user_agent",
+    "username",
+    "password",
+    "sub_name",
+    "max_days",
+    "max_posts",
+    "sleep_minutes",
+]
+
+DEFAULTS = {
+    "client_id": "",
+    "client_secret": "",
+    "user_agent": "",
+    "username": "",
+    "password": "",
+    "sub_name": "",
+    "max_days": 180,
+    "max_posts": 180,
+    "sleep_minutes": 5,
+}
+
+# Try both plain and DP_ prefix for env vars
+config = {}
+for key in CONFIG_KEYS:
+    env_val = os.getenv(key.upper())
+    if env_val is None:
+        env_val = os.getenv(f"DP_{key.upper()}")
+    if env_val is not None:
+        # Cast numeric values
+        if key in ["max_days", "max_posts", "sleep_minutes"]:
+            try:
+                config[key] = int(env_val)
+            except ValueError:
+                config[key] = DEFAULTS[key]
+        else:
+            config[key] = env_val
+    else:
+        config[key] = DEFAULTS[key]
+
+# Write config.py
+with open("config/config.py", "w", encoding="utf-8") as f:
+    f.write('"""\nConfiguration for the DeletedPosts bot.\n"""\n\n')
+    f.write('config = ' + json.dumps(config, indent=4) + '\n')
+    f.write('\nTEMPLATE = f"""# configuration for DeletedPosts bot\n# edit the values of the dictionary below and restart the bot\n\nconfig = {config!r}\n"""\n')
+
+print("config/config.py has been populated from environment variables.")