diff --git a/.gitignore b/.gitignore
index 48527d4..33ccbd0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,6 +19,9 @@ image.tar
 
 # Runtime / user data — must never be committed
 history/
+# Per-install identity (UUID) the server mints on first boot. On the box it
+# lives at /data/install-id; in local dev the server writes it to the repo root.
+/install-id
 cookies.txt
 *.txt.bak
 youtube-summarizer-library-export*.json