diff --git a/config.toml b/config.toml
index 155c656..bd2daf3 100644
--- a/config.toml
+++ b/config.toml
@@ -51,7 +51,7 @@ include_content = true
 
 [extra]
 version = "1.21.16"
-release_version = "1.21.19"
+release_version = "1.21.20"
 
 navbar_items = [
     { code = "en", nav_items = [
diff --git a/scripts/test_agent_hooks_publication.py b/scripts/test_agent_hooks_publication.py
index 95086b1..5097df8 100644
--- a/scripts/test_agent_hooks_publication.py
+++ b/scripts/test_agent_hooks_publication.py
@@ -1,4 +1,6 @@
 """Bind hook claims to actual captured failures, correction and executed output."""
+import ast
+import re
 import hashlib
 import json
 from pathlib import Path
@@ -52,6 +54,23 @@ def test_bundle_proves_hook_result_and_execution_separately(self):
                 digest, name = row.split('  ', 1)
                 self.assertEqual(hashlib.sha256(z.read(name)).hexdigest(), digest)
 
+    def test_host_prompt_delimits_an_allowed_command(self):
+        with zipfile.ZipFile(MEDIA / 'harbour-hooks-example.zip') as z:
+            tree = ast.parse(z.read('reproduce.py').decode())
+            prompt = next(ast.literal_eval(n.value) for n in tree.body
+                          if isinstance(n, ast.Assign)
+                          and any(isinstance(t, ast.Name) and t.id == 'prompt' for t in n.targets))
+            commands = re.findall(r'```sh\n([^`]+)\n```', prompt)
+            self.assertEqual(commands, ['python3 validate-brief.py --chek'])
+            config = json.loads(z.read('fixture/opencode.json'))
+            allowed = {p['resource'] for p in config['permissions']
+                       if p['action'] == 'shell' and p['effect'] == 'allow'}
+            self.assertEqual(allowed, {'python3 validate-brief.py --chek',
+                                       'python3 validate-brief.py --check'})
+            self.assertIn(commands[0], allowed)
+            self.assertNotIn(commands[0] + ' .', allowed)
+            self.assertIn('Do not repair it or add arguments, punctuation', prompt)
+
     def test_article_preserves_scope_and_downloads(self):
         page = (ROOT / 'content/how-tos/command-rewriting-howto.md').read_text()
         self.assertIn('date=2026-04-15', page)
diff --git a/static/demos/agent-hooks/harbour-hooks-example.zip b/static/demos/agent-hooks/harbour-hooks-example.zip
index 9ac6960..6897df5 100644
Binary files a/static/demos/agent-hooks/harbour-hooks-example.zip and b/static/demos/agent-hooks/harbour-hooks-example.zip differ
diff --git a/static/demos/agent-hooks/manifest.json b/static/demos/agent-hooks/manifest.json
index f1174d6..8b4832f 100644
--- a/static/demos/agent-hooks/manifest.json
+++ b/static/demos/agent-hooks/manifest.json
@@ -41,8 +41,8 @@
     },
     {
       "file": "harbour-hooks-example.zip",
-      "sha256": "f17baaaf504380209e9574d0990336d517a66f974a6f9bf27bbbab704c9acb71",
-      "bytes": 30326
+      "sha256": "bc5e8277a99dc6a7434b723a5ca0c3f20a34449b6a4527ab0721f988dd4eea45",
+      "bytes": 30482
     },
     {
       "file": "screenshots/executed-result.jpg",