diff --git a/.gitignore b/.gitignore
index 8e0a2180d..4732d9742 100644
--- a/.gitignore
+++ b/.gitignore
@@ -175,6 +175,7 @@ youtube_processed_videos/
 UVAI_Digital_Refinery_Blueprint.pdf
 *.db
 .vercel
+vercel-debug.log*
 .env*.local
 .next/
 .env
diff --git a/tests/unit/test_vercel_artifact_hygiene.py b/tests/unit/test_vercel_artifact_hygiene.py
new file mode 100644
index 000000000..f6cb94c0a
--- /dev/null
+++ b/tests/unit/test_vercel_artifact_hygiene.py
@@ -0,0 +1,13 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[2]
+
+
+def test_root_gitignore_blocks_vercel_build_and_diagnostic_artifacts() -> None:
+    source = (ROOT / ".gitignore").read_text()
+
+    assert ".vercel" in source
+    assert "vercel-debug.log*" in source