diff --git a/scripts/.vendored_canon_ref b/scripts/.vendored_canon_ref
index 42852a1a..5908f354 100644
--- a/scripts/.vendored_canon_ref
+++ b/scripts/.vendored_canon_ref
@@ -1 +1 @@
-6be694f3d6308ac0f4c2e0dcf196e2ff73f6468f
+1ad5d4088bd460f069d797a6ef0ff910e7eada1a
diff --git a/scripts/check_vendored_sync.sh b/scripts/check_vendored_sync.sh
index 27d56655..57085c10 100755
--- a/scripts/check_vendored_sync.sh
+++ b/scripts/check_vendored_sync.sh
@@ -1,22 +1,24 @@
 #!/usr/bin/env bash
-# Drift check for vendored byte-identical files (hub-and-spoke model).
+# Drift check for the vendored byte-identical id↔label files.
 #
-# THE FIX for the self-referential-pin blind spot: instead of hashing a file
-# against a hash generated FROM THE SAME REPO, this fetches the authoritative
-# copy from the canonical hub at a pinned commit and diffs. A repo that edits
-# its vendored copy now fails CI, because the reference lives elsewhere.
+# Canonical source: culturebotai-claw, shared/idlabel/. claw is private, so
+# rather than a network fetch this diffs against a LOCAL sibling checkout of
+# claw. A Mech that edits its vendored copy fails this check because the
+# reference lives in another repo.
 #
-# Dependency-free: bash + curl + diff only (no uv/OAK), so it runs as a fast
-# blocking CI job before any heavy setup. The pinned canonical commit lives in
-# scripts/.vendored_canon_ref; the file list is embedded (this script is itself
-# vendored byte-identical across the spokes). Bump .vendored_canon_ref in the
-# same PR that syncs a changed file from the hub — that bump is the deliberate
-# propagation act.
+# Resolution order for the claw checkout:
+#   1. $CLAW_ROOT (if set) — must contain shared/idlabel/
+#   2. the usual sibling locations (../culturebotai-claw, ../../…) so this works
+#      from a flat Mech (TraitMech/) and a nested one (CommunityMech/CommunityMech/)
+#
+# If no claw checkout is found (e.g. a CI runner without it), the check SKIPS
+# and exits 0 — enforcement is LOCAL, for anyone doing cross-Mech work with the
+# sibling checkout. It is NOT enforced in CI while claw is private. Making claw
+# public again lets this revert to a pinned raw-fetch that CI can run.
+#
+# Dependency-free: bash + diff only.
 set -euo pipefail
 
-CANON_REPO="CultureBotAI/CultureMech"
-REF_FILE="scripts/.vendored_canon_ref"
-
 FILES=(
   scripts/validate_id_label_correspondence.py
   scripts/chem_formula.py
@@ -25,30 +27,54 @@ FILES=(
   tests/test_id_label_plausibility.py
 )
 
-[ -f "$REF_FILE" ] || { echo "ERROR: $REF_FILE missing (pinned canonical commit)"; exit 2; }
-REF="$(tr -d '[:space:]' < "$REF_FILE")"
-[ -n "$REF" ] || { echo "ERROR: $REF_FILE is empty"; exit 2; }
+# Locate the canonical claw checkout.
+canon_dir=""
+if [ -n "${CLAW_ROOT:-}" ] && [ -d "${CLAW_ROOT}/shared/idlabel" ]; then
+  canon_dir="${CLAW_ROOT}/shared/idlabel"
+else
+  for cand in ../culturebotai-claw ../../culturebotai-claw ../../../culturebotai-claw; do
+    if [ -d "$cand/shared/idlabel" ]; then canon_dir="$cand/shared/idlabel"; break; fi
+  done
+fi
+
+if [ -z "$canon_dir" ]; then
+  echo "SKIP: culturebotai-claw checkout not found (set CLAW_ROOT to its path)."
+  echo "  Cross-repo vendored-drift is NOT enforced here (claw is private)."
+  echo "  Run locally alongside a claw checkout to enforce."
+  exit 0
+fi
+
+# If the checkout is a git repo, report which claw commit we're comparing to,
+# and warn (do not fail) when it differs from the recorded ref.
+ref_note=""
+if command -v git >/dev/null 2>&1 && git -C "$canon_dir" rev-parse HEAD >/dev/null 2>&1; then
+  head="$(git -C "$canon_dir" rev-parse --short HEAD)"
+  ref_note=" (claw@${head})"
+  if [ -f scripts/.vendored_canon_ref ]; then
+    want="$(tr -d '[:space:]' < scripts/.vendored_canon_ref)"
+    have="$(git -C "$canon_dir" rev-parse HEAD)"
+    if [ -n "$want" ] && [ "$want" != "$have" ]; then
+      echo "NOTE: local claw is at ${have:0:8}, .vendored_canon_ref pins ${want:0:8}."
+      echo "  Comparing against the local checkout; 'git -C <claw> checkout ${want:0:8}' to match the pin."
+    fi
+  fi
+fi
 
-tmp="$(mktemp)"
-trap 'rm -f "$tmp"' EXIT
 fail=0
 for f in "${FILES[@]}"; do
   [ -f "$f" ] || { echo "MISSING: $f not present locally"; fail=1; continue; }
-  url="https://raw.githubusercontent.com/${CANON_REPO}/${REF}/${f}"
-  if ! curl -fsSL "$url" -o "$tmp"; then
-    echo "ERROR: could not fetch $f from ${CANON_REPO}@${REF:0:8} ($url)"; fail=1; continue
-  fi
-  # byte-exact comparison (temp file preserves the trailing newline that $() would strip)
-  if ! cmp -s "$tmp" "$f"; then
-    echo "DRIFT: $f differs from ${CANON_REPO}@${REF:0:8}"; fail=1
+  canon="$canon_dir/$f"
+  [ -f "$canon" ] || { echo "ERROR: canonical $canon missing in claw checkout"; fail=1; continue; }
+  if ! cmp -s "$canon" "$f"; then
+    echo "DRIFT: $f differs from claw canonical$ref_note"; fail=1
   fi
 done
 
 if [ "$fail" -eq 0 ]; then
-  echo "OK: all ${#FILES[@]} vendored files match ${CANON_REPO}@${REF:0:8}"
+  echo "OK: all ${#FILES[@]} vendored files match claw canonical$ref_note"
 else
   echo ""
-  echo "To resolve: copy the canonical files from ${CANON_REPO}@${REF:0:8}, and if the"
-  echo "hub intentionally changed them, bump ${REF_FILE} to the new hub commit."
+  echo "To resolve: copy the canonical files from ${canon_dir}/, and if claw"
+  echo "intentionally changed them, bump scripts/.vendored_canon_ref to the new claw commit."
   exit 1
 fi