diff --git a/scripts/update.sh b/scripts/update.sh
index fd58c99..bf6fe0b 100644
--- a/scripts/update.sh
+++ b/scripts/update.sh
@@ -30,6 +30,6 @@ fi
 log "skills: updating from ${lockfile}..."
 jq -r '.skills[].source' "${lockfile}" | sort -u | while read -r source; do
 	log "skills: updating ${source}..."
-	npx --yes skills add --yes "${source}"
+	npx --yes skills add --yes --agent claude-code "${source}" </dev/null
 done
 log "skills: update complete."
diff --git a/tests/test_update.py b/tests/test_update.py
new file mode 100644
index 0000000..6fe44cc
--- /dev/null
+++ b/tests/test_update.py
@@ -0,0 +1,46 @@
+"""update.sh must reach every locked source and install for Claude Code only."""
+
+from __future__ import annotations
+
+import json
+import shutil
+import subprocess
+import tempfile
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+UPDATE = REPO_ROOT / "scripts" / "update.sh"
+
+
+@unittest.skipUnless(shutil.which("jq") and shutil.which("bash"), "jq or bash missing")
+class TestUpdate(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.TemporaryDirectory()
+        self.addCleanup(self.tmp.cleanup)
+        self.bin = Path(self.tmp.name)
+        self.log = self.bin / "calls.log"
+        npx = self.bin / "npx"
+        npx.write_text(f'#!/bin/sh\ncat >/dev/null\necho "$@" >> "{self.log}"\n', encoding="utf-8")
+        npx.chmod(0o755)
+        for tool in ("jq", "sort"):
+            (self.bin / tool).symlink_to(shutil.which(tool))
+
+    def test_every_source_is_updated_for_claude_code_only(self):
+        lock = json.loads((REPO_ROOT / "skills-lock.json").read_text(encoding="utf-8"))
+        sources = sorted({entry["source"] for entry in lock["skills"].values()})
+        subprocess.run(
+            ["bash", str(UPDATE)],
+            check=True,
+            capture_output=True,
+            env={"PATH": f"{self.bin}:/usr/bin:/bin"},
+            stdin=subprocess.DEVNULL,
+        )
+        calls = self.log.read_text(encoding="utf-8").splitlines()
+        self.assertEqual([c.split()[-1] for c in calls], sources)
+        for call in calls:
+            self.assertIn("--agent claude-code", call)
+
+
+if __name__ == "__main__":
+    unittest.main()