+### `--output.aspa`
+
+- **Type:** String (Path to file)
+- **Availability:** `argv` and JSON
+- **Default:** `NULL` (disabled)
+
+Assigns a file where Fort will print the valid ASPAs found after each validation run. ASPAs are always printed in JSON format.
+
+If the file already exists, it will be overwritten. If it doesn't exist, it will be created. To print to standard output, assign a hyphen (`-`).
+
+Each element is identifier by its customerASID, and its value is an array of provider ASIDs:
+
+```json
+{
+ "aspa" : {
+ "2": [ 10000, 10001, 10002 ],
+ "1513": [ 10000 ],
+ "65500": [ 4221, 61971, 87645 ],
+ "16777217": [ 39, 410, 503, 8018622 ]
+ }
+}
+```
+
+If absent, ASPAs are not printed.
+