diff --git a/local/scripts/verify-patch-content.py b/local/scripts/verify-patch-content.py
new file mode 100755
index 0000000000..0f299f0642
--- /dev/null
+++ b/local/scripts/verify-patch-content.py
@@ -0,0 +1,184 @@
+#!/usr/bin/env python3
+# verify-patch-content.sh (Python implementation) — Enforce patch-presence
+# invariant from local/AGENTS.md § "Fork Supremacy Policy":
+# "Each patch in local/patches/<comp>/ MUST be reflected in fork HEAD."
+#
+# Usage:
+#   local/scripts/verify-patch-content.sh               # Audit all forks
+#   local/scripts/verify-patch-content.sh --strict      # Exit 1 if orphans
+#   local/scripts/verify-patch-content.sh base kernel   # Audit specific forks
+#
+# Exit codes:
+#   0 — All patches preserved in fork HEAD
+#   1 — At least one orphaned patch detected (only in --strict mode)
+#
+# This is the missing check that the Phase 1.0 audit revealed:
+# no part of the build system checked that patches listed in
+# local/patches/<comp>/ had actually been absorbed into the
+# local/sources/<comp>/ fork's working tree before now.
+
+import argparse
+import os
+import re
+import subprocess
+import sys
+
+REPO_ROOT = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+COMPONENTS = {
+    'base': 'local/sources/base',
+    'bootloader': 'local/sources/bootloader',
+    'installer': 'local/sources/installer',
+    'kernel': 'local/sources/kernel',
+    'libredox': 'local/sources/libredox',
+    'redoxfs': 'local/sources/redoxfs',
+    'relibc': 'local/sources/relibc',
+    'syscall': 'local/sources/syscall',
+    'userutils': 'local/sources/userutils',
+}
+
+
+def extract_target_file(text):
+    """Get the file path that the patch modifies."""
+    m_plus = re.search(r'^\+\+\+ b/(\S+)', text, re.MULTILINE)
+    if m_plus and m_plus.group(1) != '/dev/null':
+        return m_plus.group(1)
+    m_minus = re.search(r'^--- a/(\S+)', text, re.MULTILINE)
+    if m_minus and m_minus.group(1) != '/dev/null':
+        return m_minus.group(1)
+    return None
+
+
+def extract_added_lines(text):
+    """Get the substantive added lines from a unified diff (ignoring headers)."""
+    lines = []
+    for line in text.split('\n'):
+        if line.startswith('+++') or line.startswith('---') or line.startswith('@@'):
+            continue
+        if line.startswith('+') and not line.startswith('+++'):
+            content = line[1:].strip()
+            # Skip trivial additions (timestamps, empty)
+            if content and not re.match(r'^\d{4}-\d{2}-\d{2}', content):
+                lines.append(content[:60])
+    return lines
+
+
+def audit_component(component, fork_root):
+    """Audit a single component's patch preservation status."""
+    patches_dir = os.path.join(REPO_ROOT, 'local/patches', component)
+    if not os.path.isdir(patches_dir):
+        return None  # component has no patches dir — skip
+    if not os.path.isdir(fork_root):
+        return None
+    total = 0
+    preserved = 0
+    orphaned = []
+    for fn in sorted(os.listdir(patches_dir)):
+        if not fn.endswith('.patch'):
+            continue
+        total += 1
+        ppath = os.path.join(patches_dir, fn)
+        with open(ppath, 'r', errors='ignore') as f:
+            text = f.read()
+        target = extract_target_file(text)
+        if not target:
+            orphaned.append((fn, '?', 'no-target-file'))
+            continue
+        target_path = os.path.join(fork_root, target)
+        if not os.path.exists(target_path):
+            orphaned.append((fn, target, 'target-missing-in-fork'))
+            continue
+        added = extract_added_lines(text)
+        if not added:
+            orphaned.append((fn, target, 'patch-has-no-added-lines'))
+            continue
+        try:
+            with open(target_path, 'r', errors='ignore') as f:
+                target_text = f.read()
+        except Exception:
+            orphaned.append((fn, target, 'cannot-read-target'))
+            continue
+        matched = sum(1 for line in added[:5] if line in target_text)
+        if matched >= 1:
+            preserved += 1
+        else:
+            orphaned.append((fn, target, 'no-added-line-matches'))
+    return total, preserved, orphaned
+
+
+def main():
+    ap = argparse.ArgumentParser()
+    ap.add_argument('components', nargs='*', default=list(COMPONENTS.keys()))
+    ap.add_argument('--strict', action='store_true',
+                    help='Exit non-zero if any orphaned patch detected')
+    ap.add_argument('--report', choices=['summary', 'detail'], default='summary')
+    ap.add_argument('--quiet', '-q', action='store_true')
+    args = ap.parse_args()
+
+    total_patches = 0
+    total_preserved = 0
+    total_orphaned = 0
+    failed_components = []
+    detail_lines = []
+
+    print('=' * 70)
+    print('  Red Bear OS — Patch Preservation Audit')
+    print('=' * 70)
+    print(f'  Source of truth: local/patches/<comp>/*')
+    print(f'  Fork target:     local/sources/<comp>')
+    print(f'  Strict mode:     {args.strict}')
+    print('=' * 70)
+
+    for comp in args.components:
+        if comp not in COMPONENTS:
+            print(f'  SKIP: unknown component {comp}', file=sys.stderr)
+            continue
+        fork_rel = COMPONENTS[comp]
+        fork_path = os.path.join(REPO_ROOT, fork_rel)
+        if not os.path.isdir(fork_path):
+            if not args.quiet:
+                print(f'  {comp:12s}: SKIP (fork not at {fork_rel})')
+            continue
+        result = audit_component(comp, fork_path)
+        if result is None:
+            if not args.quiet:
+                print(f'  {comp:12s}: SKIP (no patches dir)')
+            continue
+        total, preserved, orphaned = result
+        total_patches += total
+        total_preserved += preserved
+        total_orphaned += len(orphaned)
+        pct = 100 * preserved / total if total > 0 else 0
+        status = 'OK ' if not orphaned else 'WARN'
+        line = f'  [{status}] {comp:10s}: preserved={preserved}/{total}  ({pct:.0f}%)  orphaned={len(orphaned)}'
+        print(line)
+        if orphaned and args.report == 'detail':
+            detail_lines.append(f'\n  {comp} orphaned patches:')
+            for fn, target, reason in orphaned[:50]:
+                detail_lines.append(f'    - {fn}: {target} ({reason})')
+            if len(orphaned) > 50:
+                detail_lines.append(f'    ... +{len(orphaned)-50} more')
+        if orphaned:
+            failed_components.append(comp)
+
+    print('=' * 70)
+    print(f'  TOTAL: {total_patches} patches, {total_preserved} preserved, {total_orphaned} orphaned')
+    print('=' * 70)
+
+    if detail_lines:
+        print('\n'.join(detail_lines))
+
+    if total_orphaned == 0:
+        print('  ALL FORKS: patches preserved in fork HEAD')
+        return 0
+
+    print('  ACTION REQUIRED: orphaned patches must be applied to fork HEAD')
+    print('  See: local/docs/PATCH-PRESERVATION-AUDIT-2026-07-12.md')
+    print('  Helper: re-run local/scripts/apply-patches.sh and re-absorb')
+    if args.strict:
+        return 1
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/local/scripts/verify-patch-content.sh b/local/scripts/verify-patch-content.sh
new file mode 100755
index 0000000000..974cc707a9
--- /dev/null
+++ b/local/scripts/verify-patch-content.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+# Shell wrapper for verify-patch-content.py — invokes the Python audit.
+# Per local/AGENTS.md § "BRANCH AND SUBMODULE POLICY": scripts in
+# local/scripts/ MUST NOT introduce new policy; they implement existing
+# policy from AGENTS.md and local/AGENTS.md.
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+exec python3 "${SCRIPT_DIR}/verify-patch-content.py" "$@"