From ddf31b514d291d490963634f183d2b625bccba4b Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Mon, 11 May 2026 13:30:44 -0400
Subject: [PATCH 01/21] Make PrefixTrie public and implement LazyCommand class
 to defer loading plugins until commands are invoked.

---
 awscli/botocore/hooks.py          |   4 +-
 awscli/lazy.py                    |  60 +++++++++++++
 tests/functional/test_lazy.py     |  87 +++++++++++++++++++
 tests/unit/botocore/test_hooks.py |  54 +++++++++++-
 tests/unit/test_lazy.py           | 139 ++++++++++++++++++++++++++++++
 5 files changed, 341 insertions(+), 3 deletions(-)
 create mode 100644 awscli/lazy.py
 create mode 100644 tests/functional/test_lazy.py
 create mode 100644 tests/unit/test_lazy.py

diff --git a/awscli/botocore/hooks.py b/awscli/botocore/hooks.py
index 90db67d6fe69..1530bbf158ee 100644
--- a/awscli/botocore/hooks.py
+++ b/awscli/botocore/hooks.py
@@ -196,7 +196,7 @@ def __init__(self):
         # read only access (we never modify self._handlers).
         # A cache of event name to handler list.
         self._lookup_cache = {}
-        self._handlers = _PrefixTrie()
+        self._handlers = PrefixTrie()
         # This is used to ensure that unique_id's are only
         # registered once.
         self._unique_id_handlers = {}
@@ -398,7 +398,7 @@ def __copy__(self):
         return new_instance
 
 
-class _PrefixTrie:
+class PrefixTrie:
     """Specialized prefix trie that handles wildcards.
 
     The prefixes in this case are based on dot separated
diff --git a/awscli/lazy.py b/awscli/lazy.py
new file mode 100644
index 000000000000..4cad0964443d
--- /dev/null
+++ b/awscli/lazy.py
@@ -0,0 +1,60 @@
+import importlib
+
+from awscli.commands import CLICommand
+
+
+class LazyCommand(CLICommand):
+    """A command-table entry that defers importing its real implementation.
+
+    Sits in the command table like any other CLICommand, but only imports
+    the actual module (and creates the real command object) when the command
+    is invoked or its help is accessed.
+    """
+
+    def __init__(self, name, session, module_path, class_name):
+        self._name = name
+        self._session = session
+        self._module_path = module_path
+        self._class_name = class_name
+        self._real = None
+        self._lineage = [self]
+
+    def _resolve(self):
+        if self._real is None:
+            mod = importlib.import_module(self._module_path)
+            cls = getattr(mod, self._class_name)
+            self._real = cls(self._session)
+            self._real.lineage = self._lineage
+        return self._real
+
+    def __call__(self, args, parsed_globals):
+        return self._resolve()(args, parsed_globals)
+
+    def create_help_command(self):
+        return self._resolve().create_help_command()
+
+    @property
+    def arg_table(self):
+        return self._resolve().arg_table
+
+    @property
+    def subcommand_table(self):
+        return self._resolve().subcommand_table
+
+    @property
+    def name(self):
+        return self._name
+
+    @name.setter
+    def name(self, value):
+        self._name = value
+
+    @property
+    def lineage(self):
+        return self._lineage
+
+    @lineage.setter
+    def lineage(self, value):
+        self._lineage = value
+        if self._real is not None:
+            self._real.lineage = value
diff --git a/tests/functional/test_lazy.py b/tests/functional/test_lazy.py
new file mode 100644
index 000000000000..3ba067e13aad
--- /dev/null
+++ b/tests/functional/test_lazy.py
@@ -0,0 +1,87 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+import pytest
+
+from awscli.handlers_registry import MAIN_COMMAND_TABLE_OPS
+from awscli.lazy import LazyCommand
+from awscli.testutils import BaseAWSHelpOutputTest, mock
+
+# Derive test parameters from MAIN_COMMAND_TABLE_OPS.
+_ADD_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == 'add']
+_RENAME_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == 'rename']
+_ADD_CMD_NAMES = [op[1] for op in _ADD_OPS]
+_RENAME_NEW_NAMES = [op[2] for op in _RENAME_OPS]
+
+
+class TestLazyCommandHelpRenders(BaseAWSHelpOutputTest):
+    def test_added_command_help_renders(self):
+        for cmd_name in _ADD_CMD_NAMES:
+            with self.subTest(cmd_name=cmd_name):
+                self.driver.main([cmd_name, 'help'])
+                self.assert_contains(cmd_name)
+
+    def test_renamed_command_help_renders(self):
+        for new_name in _RENAME_NEW_NAMES:
+            with self.subTest(new_name=new_name):
+                self.driver.main([new_name, 'help'])
+                self.assert_contains(new_name)
+
+
+class TestLazyCommandIsTransparent(BaseAWSHelpOutputTest):
+    def test_added_commands_appear_in_top_level_help(self):
+        self.driver.main(['help'])
+        for cmd_name in _ADD_CMD_NAMES:
+            self.assert_contains(cmd_name)
+
+    def test_lazy_command_has_subcommands(self):
+        command_table = self.driver.subcommand_table
+        s3_cmd = command_table['s3']
+        assert isinstance(s3_cmd, LazyCommand)
+        subcommands = s3_cmd.subcommand_table
+        assert 'ls' in subcommands
+        assert 'cp' in subcommands
+
+
+class TestLazyCommandErrorPaths:
+    def test_invalid_module_path_raises_on_resolve(self):
+        session = mock.MagicMock()
+        cmd = LazyCommand(
+            'bad-cmd',
+            session,
+            'awscli.nonexistent.module',
+            'FakeCommand',
+        )
+        with pytest.raises(ModuleNotFoundError):
+            cmd([], mock.MagicMock())
+
+    def test_invalid_class_name_raises_on_resolve(self):
+        session = mock.MagicMock()
+        cmd = LazyCommand(
+            'bad-cmd',
+            session,
+            'awscli.customizations.dynamodb.ddb',
+            'NonexistentClass',
+        )
+        with pytest.raises(AttributeError):
+            cmd([], mock.MagicMock())
+
+    def test_invalid_module_path_raises_on_help(self):
+        session = mock.MagicMock()
+        cmd = LazyCommand(
+            'bad-cmd',
+            session,
+            'awscli.nonexistent.module',
+            'FakeCommand',
+        )
+        with pytest.raises(ModuleNotFoundError):
+            cmd.create_help_command()
diff --git a/tests/unit/botocore/test_hooks.py b/tests/unit/botocore/test_hooks.py
index 23d9b4985d6c..4defdd5511dc 100644
--- a/tests/unit/botocore/test_hooks.py
+++ b/tests/unit/botocore/test_hooks.py
@@ -14,7 +14,11 @@
 import functools
 from functools import partial
 
-from botocore.hooks import HierarchicalEmitter, first_non_none_response
+from botocore.hooks import (
+    HierarchicalEmitter,
+    PrefixTrie,
+    first_non_none_response,
+)
 
 from tests import unittest
 
@@ -584,5 +588,53 @@ def handler(a, b, **kwargs):
         )
 
 
+class TestPrefixTrie(unittest.TestCase):
+    def setUp(self):
+        self.trie = PrefixTrie()
+
+    def test_append_and_prefix_search_exact_match(self):
+        self.trie.append_item('building-command-table.main', 'handler1')
+        results = self.trie.prefix_search('building-command-table.main')
+        self.assertIn('handler1', results)
+
+    def test_prefix_search_matches_parent(self):
+        self.trie.append_item('building-command-table', 'handler1')
+        results = self.trie.prefix_search('building-command-table.main')
+        self.assertIn('handler1', results)
+
+    def test_prefix_search_does_not_match_sibling(self):
+        self.trie.append_item('building-command-table.ecs', 'handler1')
+        results = self.trie.prefix_search('building-command-table.main')
+        self.assertNotIn('handler1', results)
+
+    def test_prefix_search_does_not_match_child(self):
+        self.trie.append_item('building-command-table.main.sub', 'handler1')
+        results = self.trie.prefix_search('building-command-table.main')
+        self.assertNotIn('handler1', results)
+
+    def test_wildcard_match(self):
+        self.trie.append_item('building-command-table.*', 'handler1')
+        results = self.trie.prefix_search('building-command-table.main')
+        self.assertIn('handler1', results)
+
+    def test_multiple_items_at_same_key(self):
+        self.trie.append_item('building-command-table.main', 'handler1')
+        self.trie.append_item('building-command-table.main', 'handler2')
+        results = self.trie.prefix_search('building-command-table.main')
+        self.assertIn('handler1', results)
+        self.assertIn('handler2', results)
+
+    def test_multiple_levels_all_returned(self):
+        self.trie.append_item('building-command-table', 'parent')
+        self.trie.append_item('building-command-table.main', 'exact')
+        results = self.trie.prefix_search('building-command-table.main')
+        self.assertIn('parent', results)
+        self.assertIn('exact', results)
+
+    def test_empty_trie_returns_empty(self):
+        results = self.trie.prefix_search('building-command-table.main')
+        self.assertEqual(len(results), 0)
+
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/tests/unit/test_lazy.py b/tests/unit/test_lazy.py
new file mode 100644
index 000000000000..63a1ff5ea44b
--- /dev/null
+++ b/tests/unit/test_lazy.py
@@ -0,0 +1,139 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from awscli.lazy import LazyCommand
+
+
+@pytest.fixture
+def session():
+    return MagicMock()
+
+
+@pytest.fixture
+def mock_command_class():
+    cls = MagicMock()
+    instance = MagicMock()
+    cls.return_value = instance
+    return cls
+
+
+@pytest.fixture
+def mock_module(mock_command_class):
+    module = MagicMock()
+    module.MyCommand = mock_command_class
+    return module
+
+
+class TestLazyCommandResolution:
+    def test_does_not_import_on_construction(self, session):
+        with patch('importlib.import_module') as imp:
+            LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        imp.assert_not_called()
+
+    def test_imports_module_on_call(self, session, mock_module):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        with patch('importlib.import_module', return_value=mock_module):
+            cmd(['arg1'], MagicMock())
+        mock_module.MyCommand.assert_called_once_with(session)
+
+    def test_imports_module_on_help(self, session, mock_module):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        with patch('importlib.import_module', return_value=mock_module):
+            cmd.create_help_command()
+        mock_module.MyCommand.assert_called_once_with(session)
+
+    def test_imports_module_on_arg_table(self, session, mock_module):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        with patch('importlib.import_module', return_value=mock_module):
+            _ = cmd.arg_table
+        mock_module.MyCommand.assert_called_once_with(session)
+
+    def test_imports_module_on_subcommand_table(self, session, mock_module):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        with patch('importlib.import_module', return_value=mock_module):
+            _ = cmd.subcommand_table
+        mock_module.MyCommand.assert_called_once_with(session)
+
+    def test_resolves_only_once(self, session, mock_module):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        with patch('importlib.import_module', return_value=mock_module) as imp:
+            cmd(['arg1'], MagicMock())
+            cmd(['arg2'], MagicMock())
+        imp.assert_called_once_with('some.module')
+
+    def test_delegates_call_to_real_command(self, session, mock_module):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        args = ['arg1']
+        parsed_globals = MagicMock()
+        with patch('importlib.import_module', return_value=mock_module):
+            cmd(args, parsed_globals)
+        mock_module.MyCommand.return_value.assert_called_once_with(
+            args, parsed_globals
+        )
+
+    def test_delegates_help_to_real_command(self, session, mock_module):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        with patch('importlib.import_module', return_value=mock_module):
+            result = cmd.create_help_command()
+        assert (
+            result == mock_module.MyCommand.return_value.create_help_command()
+        )
+
+
+class TestLazyCommandProperties:
+    def test_name_returns_initial_name(self, session):
+        cmd = LazyCommand('my-cmd', session, 'some.module', 'MyCommand')
+        assert cmd.name == 'my-cmd'
+
+    def test_name_setter_updates_name(self, session):
+        cmd = LazyCommand('old-name', session, 'some.module', 'MyCommand')
+        cmd.name = 'new-name'
+        assert cmd.name == 'new-name'
+
+    def test_lineage_defaults_to_self(self, session):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        assert cmd.lineage == [cmd]
+
+    def test_lineage_setter_updates_lineage(self, session):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        new_lineage = [MagicMock(), cmd]
+        cmd.lineage = new_lineage
+        assert cmd.lineage == new_lineage
+
+    def test_lineage_propagated_to_real_on_resolve(self, session, mock_module):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        new_lineage = [MagicMock(), cmd]
+        cmd.lineage = new_lineage
+        with patch('importlib.import_module', return_value=mock_module):
+            cmd.create_help_command()
+        assert mock_module.MyCommand.return_value.lineage == new_lineage
+
+    def test_lineage_setter_propagates_to_already_resolved(
+        self, session, mock_module
+    ):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        with patch('importlib.import_module', return_value=mock_module):
+            cmd.create_help_command()
+        new_lineage = [MagicMock(), cmd]
+        cmd.lineage = new_lineage
+        assert mock_module.MyCommand.return_value.lineage == new_lineage
+
+    def test_lineage_not_propagated_if_not_resolved(self, session):
+        cmd = LazyCommand('cmd', session, 'some.module', 'MyCommand')
+        new_lineage = [MagicMock(), cmd]
+        # Should not raise even though underlying command is not resolved.
+        cmd.lineage = new_lineage
+        assert cmd.lineage == new_lineage

From dab19fb02ba42ff07547dab9f07bb1f58f9389d7 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Mon, 11 May 2026 13:56:34 -0400
Subject: [PATCH 02/21] Remove parts of functional/test_lazy.py that depend on
 LazyInitEmitter.

---
 tests/functional/test_lazy.py | 38 +----------------------------------
 1 file changed, 1 insertion(+), 37 deletions(-)

diff --git a/tests/functional/test_lazy.py b/tests/functional/test_lazy.py
index 3ba067e13aad..fc8d33edd359 100644
--- a/tests/functional/test_lazy.py
+++ b/tests/functional/test_lazy.py
@@ -12,44 +12,8 @@
 # language governing permissions and limitations under the License.
 import pytest
 
-from awscli.handlers_registry import MAIN_COMMAND_TABLE_OPS
 from awscli.lazy import LazyCommand
-from awscli.testutils import BaseAWSHelpOutputTest, mock
-
-# Derive test parameters from MAIN_COMMAND_TABLE_OPS.
-_ADD_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == 'add']
-_RENAME_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == 'rename']
-_ADD_CMD_NAMES = [op[1] for op in _ADD_OPS]
-_RENAME_NEW_NAMES = [op[2] for op in _RENAME_OPS]
-
-
-class TestLazyCommandHelpRenders(BaseAWSHelpOutputTest):
-    def test_added_command_help_renders(self):
-        for cmd_name in _ADD_CMD_NAMES:
-            with self.subTest(cmd_name=cmd_name):
-                self.driver.main([cmd_name, 'help'])
-                self.assert_contains(cmd_name)
-
-    def test_renamed_command_help_renders(self):
-        for new_name in _RENAME_NEW_NAMES:
-            with self.subTest(new_name=new_name):
-                self.driver.main([new_name, 'help'])
-                self.assert_contains(new_name)
-
-
-class TestLazyCommandIsTransparent(BaseAWSHelpOutputTest):
-    def test_added_commands_appear_in_top_level_help(self):
-        self.driver.main(['help'])
-        for cmd_name in _ADD_CMD_NAMES:
-            self.assert_contains(cmd_name)
-
-    def test_lazy_command_has_subcommands(self):
-        command_table = self.driver.subcommand_table
-        s3_cmd = command_table['s3']
-        assert isinstance(s3_cmd, LazyCommand)
-        subcommands = s3_cmd.subcommand_table
-        assert 'ls' in subcommands
-        assert 'cp' in subcommands
+from awscli.testutils import mock
 
 
 class TestLazyCommandErrorPaths:

From 494bd6a047a10694478ef663ba9a1ce720ebf156 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Mon, 11 May 2026 14:04:28 -0400
Subject: [PATCH 03/21] Add license header to awscli/lazy.py.

---
 awscli/lazy.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/awscli/lazy.py b/awscli/lazy.py
index 4cad0964443d..58eccd7df515 100644
--- a/awscli/lazy.py
+++ b/awscli/lazy.py
@@ -1,3 +1,15 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
 import importlib
 
 from awscli.commands import CLICommand

From 40f4027c699a18d34f28f3d6d0f7bb27090e4dc0 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 13 May 2026 11:18:59 -0400
Subject: [PATCH 04/21] Switch new test suite to use PyTest instead of
 unittest.TestCase.

---
 tests/unit/botocore/test_hooks.py | 96 ++++++++++++++++---------------
 1 file changed, 50 insertions(+), 46 deletions(-)

diff --git a/tests/unit/botocore/test_hooks.py b/tests/unit/botocore/test_hooks.py
index 4defdd5511dc..cb7e1d738131 100644
--- a/tests/unit/botocore/test_hooks.py
+++ b/tests/unit/botocore/test_hooks.py
@@ -14,6 +14,8 @@
 import functools
 from functools import partial
 
+import pytest
+
 from botocore.hooks import (
     HierarchicalEmitter,
     PrefixTrie,
@@ -588,52 +590,54 @@ def handler(a, b, **kwargs):
         )
 
 
-class TestPrefixTrie(unittest.TestCase):
-    def setUp(self):
-        self.trie = PrefixTrie()
-
-    def test_append_and_prefix_search_exact_match(self):
-        self.trie.append_item('building-command-table.main', 'handler1')
-        results = self.trie.prefix_search('building-command-table.main')
-        self.assertIn('handler1', results)
-
-    def test_prefix_search_matches_parent(self):
-        self.trie.append_item('building-command-table', 'handler1')
-        results = self.trie.prefix_search('building-command-table.main')
-        self.assertIn('handler1', results)
-
-    def test_prefix_search_does_not_match_sibling(self):
-        self.trie.append_item('building-command-table.ecs', 'handler1')
-        results = self.trie.prefix_search('building-command-table.main')
-        self.assertNotIn('handler1', results)
-
-    def test_prefix_search_does_not_match_child(self):
-        self.trie.append_item('building-command-table.main.sub', 'handler1')
-        results = self.trie.prefix_search('building-command-table.main')
-        self.assertNotIn('handler1', results)
-
-    def test_wildcard_match(self):
-        self.trie.append_item('building-command-table.*', 'handler1')
-        results = self.trie.prefix_search('building-command-table.main')
-        self.assertIn('handler1', results)
-
-    def test_multiple_items_at_same_key(self):
-        self.trie.append_item('building-command-table.main', 'handler1')
-        self.trie.append_item('building-command-table.main', 'handler2')
-        results = self.trie.prefix_search('building-command-table.main')
-        self.assertIn('handler1', results)
-        self.assertIn('handler2', results)
-
-    def test_multiple_levels_all_returned(self):
-        self.trie.append_item('building-command-table', 'parent')
-        self.trie.append_item('building-command-table.main', 'exact')
-        results = self.trie.prefix_search('building-command-table.main')
-        self.assertIn('parent', results)
-        self.assertIn('exact', results)
-
-    def test_empty_trie_returns_empty(self):
-        results = self.trie.prefix_search('building-command-table.main')
-        self.assertEqual(len(results), 0)
+@pytest.fixture
+def trie():
+    return PrefixTrie()
+
+
+class TestPrefixTrie:
+    def test_append_and_prefix_search_exact_match(self, trie):
+        trie.append_item('building-command-table.main', 'handler1')
+        results = trie.prefix_search('building-command-table.main')
+        assert 'handler1' in results
+
+    def test_prefix_search_matches_parent(self, trie):
+        trie.append_item('building-command-table', 'handler1')
+        results = trie.prefix_search('building-command-table.main')
+        assert 'handler1' in results
+
+    def test_prefix_search_does_not_match_sibling(self, trie):
+        trie.append_item('building-command-table.ecs', 'handler1')
+        results = trie.prefix_search('building-command-table.main')
+        assert 'handler1' not in results
+
+    def test_prefix_search_does_not_match_child(self, trie):
+        trie.append_item('building-command-table.main.sub', 'handler1')
+        results = trie.prefix_search('building-command-table.main')
+        assert 'handler1' not in results
+
+    def test_wildcard_match(self, trie):
+        trie.append_item('building-command-table.*', 'handler1')
+        results = trie.prefix_search('building-command-table.main')
+        assert 'handler1' in results
+
+    def test_multiple_items_at_same_key(self, trie):
+        trie.append_item('building-command-table.main', 'handler1')
+        trie.append_item('building-command-table.main', 'handler2')
+        results = trie.prefix_search('building-command-table.main')
+        assert 'handler1' in results
+        assert 'handler2' in results
+
+    def test_multiple_levels_all_returned(self, trie):
+        trie.append_item('building-command-table', 'parent')
+        trie.append_item('building-command-table.main', 'exact')
+        results = trie.prefix_search('building-command-table.main')
+        assert 'parent' in results
+        assert 'exact' in results
+
+    def test_empty_trie_returns_empty(self, trie):
+        results = trie.prefix_search('building-command-table.main')
+        assert len(results) == 0
 
 
 if __name__ == '__main__':

From fdddde11812c7f6e9531a0b81c10b5d328d1b04f Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 13 May 2026 11:19:36 -0400
Subject: [PATCH 05/21] Formatting.

---
 tests/unit/botocore/test_hooks.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tests/unit/botocore/test_hooks.py b/tests/unit/botocore/test_hooks.py
index cb7e1d738131..b55e98bd1e77 100644
--- a/tests/unit/botocore/test_hooks.py
+++ b/tests/unit/botocore/test_hooks.py
@@ -15,7 +15,6 @@
 from functools import partial
 
 import pytest
-
 from botocore.hooks import (
     HierarchicalEmitter,
     PrefixTrie,

From c8b4b7b671c18afd5daf46f03ee3ae0b497ad6ee Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 13 May 2026 14:06:37 -0400
Subject: [PATCH 06/21] Wrap plugins that directly register against events in
 handlers.py in a thin initialization function.

---
 awscli/argprocess.py                          |   7 +
 awscli/clidriver.py                           |   7 +
 awscli/customizations/addexamples.py          |  14 ++
 awscli/customizations/binaryformat.py         |   7 +
 .../customizations/codedeploy/codedeploy.py   |   8 +-
 awscli/customizations/ec2/decryptpassword.py  |   7 +
 awscli/customizations/iot.py                  |  14 ++
 awscli/customizations/s3/s3.py                |  21 +--
 awscli/customizations/streamingoutputarg.py   |   7 +
 awscli/handlers.py                            |  73 ++++-----
 awscli/paramfile.py                           |   7 +
 tests/functional/test_handlers_registry.py    | 155 ++++++++++++++++++
 tests/unit/customizations/s3/test_s3.py       |   9 +-
 13 files changed, 272 insertions(+), 64 deletions(-)
 create mode 100644 tests/functional/test_handlers_registry.py

diff --git a/awscli/argprocess.py b/awscli/argprocess.py
index fdc5eee8ba85..529ca1cd53e2 100644
--- a/awscli/argprocess.py
+++ b/awscli/argprocess.py
@@ -270,6 +270,13 @@ def _is_complex_shape(model):
     return True
 
 
+def register_param_shorthand_parser(event_emitter):
+    event_emitter.register(
+        'process-cli-arg',
+        ParamShorthandParser(),
+    )
+
+
 class ParamShorthand:
     def _uses_old_list_case(self, command_name, operation_name, argument_name):
         """
diff --git a/awscli/clidriver.py b/awscli/clidriver.py
index 643331c50d46..f7ba957fd94f 100644
--- a/awscli/clidriver.py
+++ b/awscli/clidriver.py
@@ -214,6 +214,13 @@ def _set_user_agent_for_session(session):
     add_session_id_component_to_user_agent_extra(session)
 
 
+def register_no_pager_handler(event_emitter):
+    event_emitter.register(
+        'session-initialized',
+        no_pager_handler,
+    )
+
+
 def no_pager_handler(session, parsed_args, **kwargs):
     if parsed_args.no_cli_pager:
         config_store = session.get_component('config_store')
diff --git a/awscli/customizations/addexamples.py b/awscli/customizations/addexamples.py
index 49a9ed65b55c..9ccf670ec6e8 100644
--- a/awscli/customizations/addexamples.py
+++ b/awscli/customizations/addexamples.py
@@ -33,6 +33,20 @@
 LOG = logging.getLogger(__name__)
 
 
+def register_docs_add_examples(event_emitter):
+
+    # The following will get fired for every option we are
+    # documenting.  It will attempt to add an example_fn on to
+    # the parameter object if the parameter supports shorthand
+    # syntax.  The documentation event handlers will then use
+    # the examplefn to generate the sample shorthand syntax
+    # in the docs.  Registering here should ensure that this
+    # handler gets called first, but it still feels a bit brittle.
+    # event_handlers.register('doc-option-example.*.*.*',
+    #                        param_shorthand.add_example_fn)
+    event_emitter.register('doc-examples.*.*', add_examples)
+
+
 def add_examples(help_command, **kwargs):
     doc_path = os.path.join(
         os.path.dirname(os.path.dirname(os.path.abspath(__file__))), 'examples'
diff --git a/awscli/customizations/binaryformat.py b/awscli/customizations/binaryformat.py
index 7ac8030231c7..4812047fdf39 100644
--- a/awscli/customizations/binaryformat.py
+++ b/awscli/customizations/binaryformat.py
@@ -18,6 +18,13 @@
 from awscli.shorthand import ModelVisitor
 
 
+def register_init_binary_formatter(event_emitter):
+    event_emitter.register(
+        'session-initialized',
+        add_binary_formatter,
+    )
+
+
 def add_binary_formatter(session, parsed_args, **kwargs):
     binary_format = parsed_args.cli_binary_format
     if binary_format is None:
diff --git a/awscli/customizations/codedeploy/codedeploy.py b/awscli/customizations/codedeploy/codedeploy.py
index b1c78d648f0e..873511958909 100644
--- a/awscli/customizations/codedeploy/codedeploy.py
+++ b/awscli/customizations/codedeploy/codedeploy.py
@@ -22,11 +22,11 @@
 from awscli.customizations.codedeploy.uninstall import Uninstall
 
 
-def initialize(cli):
-    """
-    The entry point for CodeDeploy high level commands.
-    """
+def register_rename_codedeploy(cli):
     cli.register('building-command-table.main', change_name)
+
+
+def register_codedeploy(cli):
     cli.register('building-command-table.deploy', inject_commands)
     cli.register(
         'building-argument-table.deploy.get-application-revision',
diff --git a/awscli/customizations/ec2/decryptpassword.py b/awscli/customizations/ec2/decryptpassword.py
index 4fba23fb59f0..902cd4c800cd 100644
--- a/awscli/customizations/ec2/decryptpassword.py
+++ b/awscli/customizations/ec2/decryptpassword.py
@@ -27,6 +27,13 @@
 password data sent from EC2 will be decrypted before display.</p>"""
 
 
+def register_ec2_add_priv_launch_key(event_emitter, **kwargs):
+    event_emitter.register(
+        'building-argument-table.ec2.get-password-data',
+        ec2_add_priv_launch_key,
+    )
+
+
 def ec2_add_priv_launch_key(
     argument_table, operation_model, session, **kwargs
 ):
diff --git a/awscli/customizations/iot.py b/awscli/customizations/iot.py
index f4e4b9770513..8b0153d6fcc5 100644
--- a/awscli/customizations/iot.py
+++ b/awscli/customizations/iot.py
@@ -26,6 +26,20 @@
 from awscli.customizations.arguments import QueryOutFileArgument
 
 
+def register_iot_create_keys_from_csr(event_emitter):
+    event_emitter.register(
+        'building-argument-table.iot.create-certificate-from-csr',
+        register_create_keys_from_csr_arguments,
+    )
+
+
+def register_iot_create_keys_and_cert_args(event_emitter):
+    event_emitter.register(
+        'building-argument-table.iot.create-keys-and-certificate',
+        register_create_keys_and_cert_arguments,
+    )
+
+
 def register_create_keys_and_cert_arguments(session, argument_table, **kwargs):
     """Add outfile save arguments to create-keys-and-certificate
 
diff --git a/awscli/customizations/s3/s3.py b/awscli/customizations/s3/s3.py
index 725bd0ca9bf7..9dad2aaa03d1 100644
--- a/awscli/customizations/s3/s3.py
+++ b/awscli/customizations/s3/s3.py
@@ -28,23 +28,14 @@
 )
 
 
-def awscli_initialize(cli):
-    """
-    This function is require to use the plugin.  It calls the functions
-    required to add all necessary commands and parameters to the CLI.
-    This function is necessary to install the plugin using a configuration
-    file
-    """
-    cli.register("building-command-table.main", add_s3)
-    cli.register('building-command-table.s3_sync', register_sync_strategies)
+def register_s3_main(event_handlers):
+    event_handlers.register('building-command-table.main', add_s3)
 
 
-def s3_plugin_initialize(event_handlers):
-    """
-    This is a wrapper to make the plugin built-in to the cli as opposed
-    to specifying it in the configuration file.
-    """
-    awscli_initialize(event_handlers)
+def register_s3_sync_strategies(event_handlers):
+    event_handlers.register(
+        'building-command-table.s3_sync', register_sync_strategies
+    )
 
 
 def add_s3(command_table, session, **kwargs):
diff --git a/awscli/customizations/streamingoutputarg.py b/awscli/customizations/streamingoutputarg.py
index c4decbb6844d..6c289c0ec140 100644
--- a/awscli/customizations/streamingoutputarg.py
+++ b/awscli/customizations/streamingoutputarg.py
@@ -15,6 +15,13 @@
 from awscli.arguments import BaseCLIArgument
 
 
+def register_streaming_output_arg(event_emitter):
+    event_emitter.register(
+        'building-argument-table.*',
+        add_streaming_output_arg,
+    )
+
+
 def add_streaming_output_arg(
     argument_table, operation_model, session, **kwargs
 ):
diff --git a/awscli/handlers.py b/awscli/handlers.py
index 3f0aa0180078..bc5234a4a7f9 100644
--- a/awscli/handlers.py
+++ b/awscli/handlers.py
@@ -18,14 +18,14 @@
 """
 
 from awscli.alias import register_alias_commands
-from awscli.argprocess import ParamShorthandParser
-from awscli.clidriver import no_pager_handler
+from awscli.argprocess import register_param_shorthand_parser
+from awscli.clidriver import register_no_pager_handler
 from awscli.customizations import datapipeline
-from awscli.customizations.addexamples import add_examples
+from awscli.customizations.addexamples import register_docs_add_examples
 from awscli.customizations.argrename import register_arg_renames
 from awscli.customizations.assumerole import register_assume_role_provider
 from awscli.customizations.awslambda import register_lambda_create_function
-from awscli.customizations.binaryformat import add_binary_formatter
+from awscli.customizations.binaryformat import register_init_binary_formatter
 from awscli.customizations.cliinput import register_cli_input_args
 from awscli.customizations.cloudformation import (
     initialize as cloudformation_init,
@@ -38,7 +38,8 @@
 from awscli.customizations.codeartifact import register_codeartifact_commands
 from awscli.customizations.codecommit import initialize as codecommit_init
 from awscli.customizations.codedeploy.codedeploy import (
-    initialize as codedeploy_init,
+    register_codedeploy,
+    register_rename_codedeploy as codedeploy_init,
 )
 from awscli.customizations.configservice.getstatus import register_get_status
 from awscli.customizations.configservice.putconfigurationrecorder import (
@@ -58,7 +59,9 @@
 )
 from awscli.customizations.ec2.addcount import register_count_events
 from awscli.customizations.ec2.bundleinstance import register_bundleinstance
-from awscli.customizations.ec2.decryptpassword import ec2_add_priv_launch_key
+from awscli.customizations.ec2.decryptpassword import (
+    register_ec2_add_priv_launch_key
+)
 from awscli.customizations.ec2.paginate import register_ec2_page_size_injector
 from awscli.customizations.ec2.protocolarg import register_protocol_args
 from awscli.customizations.ec2.runinstances import register_runinstances
@@ -88,8 +91,8 @@
 )
 from awscli.customizations.iamvirtmfa import IAMVMFAWrapper
 from awscli.customizations.iot import (
-    register_create_keys_and_cert_arguments,
-    register_create_keys_from_csr_arguments,
+    register_iot_create_keys_and_cert_args,
+    register_iot_create_keys_from_csr,
 )
 from awscli.customizations.iot_data import register_custom_endpoint_note
 from awscli.customizations.kinesis import (
@@ -113,7 +116,10 @@
 )
 from awscli.customizations.removals import register_removals
 from awscli.customizations.route53 import register_create_hosted_zone_doc_fix
-from awscli.customizations.s3.s3 import s3_plugin_initialize
+from awscli.customizations.s3.s3 import (
+    register_s3_main,
+    register_s3_sync_strategies
+)
 from awscli.customizations.s3errormsg import register_s3_error_msg
 from awscli.customizations.s3events import (
     register_document_expires_string,
@@ -125,7 +131,7 @@
 from awscli.customizations.sessendemail import register_ses_send_email
 from awscli.customizations.sessionmanager import register_ssm_session
 from awscli.customizations.sso import register_sso_commands
-from awscli.customizations.streamingoutputarg import add_streaming_output_arg
+from awscli.customizations.streamingoutputarg import register_streaming_output_arg
 from awscli.customizations.timestampformat import register_timestamp_format
 from awscli.customizations.toplevelbool import register_bool_params
 from awscli.customizations.translate import (
@@ -133,42 +139,28 @@
 )
 from awscli.customizations.waiters import register_add_waiters
 from awscli.customizations.wizard.commands import register_wizard_commands
-from awscli.paramfile import register_uri_param_handler
+from awscli.paramfile import register_init_uri_param_handler
 
 
 def awscli_initialize(event_handlers):
-    event_handlers.register('session-initialized', register_uri_param_handler)
-    event_handlers.register('session-initialized', add_binary_formatter)
-    event_handlers.register('session-initialized', no_pager_handler)
-    param_shorthand = ParamShorthandParser()
-    event_handlers.register('process-cli-arg', param_shorthand)
-    # The s3 error mesage needs to registered before the
+    register_init_uri_param_handler(event_handlers)
+    register_init_binary_formatter(event_handlers)
+    register_no_pager_handler(event_handlers)
+    register_param_shorthand_parser(event_handlers)
+    # The s3 error message needs to registered before the
     # generic error handler.
     register_s3_error_msg(event_handlers)
-    #    # The following will get fired for every option we are
-    #    # documenting.  It will attempt to add an example_fn on to
-    #    # the parameter object if the parameter supports shorthand
-    #    # syntax.  The documentation event handlers will then use
-    #    # the examplefn to generate the sample shorthand syntax
-    #    # in the docs.  Registering here should ensure that this
-    #    # handler gets called first but it still feels a bit brittle.
-    #    event_handlers.register('doc-option-example.*.*.*',
-    #                            param_shorthand.add_example_fn)
-    event_handlers.register('doc-examples.*.*', add_examples)
+    register_docs_add_examples(event_handlers)
     register_cli_input_args(event_handlers)
-    event_handlers.register(
-        'building-argument-table.*', add_streaming_output_arg
-    )
+    register_streaming_output_arg(event_handlers)
     register_count_events(event_handlers)
-    event_handlers.register(
-        'building-argument-table.ec2.get-password-data',
-        ec2_add_priv_launch_key,
-    )
+    register_ec2_add_priv_launch_key(event_handlers)
     register_parse_global_args(event_handlers)
     register_pagination(event_handlers)
     register_secgroup(event_handlers)
     register_bundleinstance(event_handlers)
-    s3_plugin_initialize(event_handlers)
+    register_s3_main(event_handlers)
+    register_s3_sync_strategies(event_handlers)
     register_ddb(event_handlers)
     register_runinstances(event_handlers)
     register_removals(event_handlers)
@@ -199,6 +191,7 @@ def awscli_initialize(event_handlers):
     register_assume_role_provider(event_handlers)
     register_add_waiters(event_handlers)
     codedeploy_init(event_handlers)
+    register_codedeploy(event_handlers)
     register_subscribe(event_handlers)
     register_get_status(event_handlers)
     register_rename_config(event_handlers)
@@ -210,14 +203,8 @@ def awscli_initialize(event_handlers):
     register_codeartifact_commands(event_handlers)
     codecommit_init(event_handlers)
     register_custom_endpoint_note(event_handlers)
-    event_handlers.register(
-        'building-argument-table.iot.create-keys-and-certificate',
-        register_create_keys_and_cert_arguments,
-    )
-    event_handlers.register(
-        'building-argument-table.iot.create-certificate-from-csr',
-        register_create_keys_from_csr_arguments,
-    )
+    register_iot_create_keys_and_cert_args(event_handlers)
+    register_iot_create_keys_from_csr(event_handlers)
     register_cloudfront(event_handlers)
     register_gamelift_commands(event_handlers)
     register_ec2_page_size_injector(event_handlers)
diff --git a/awscli/paramfile.py b/awscli/paramfile.py
index 975470062594..a14b3c56b3fa 100644
--- a/awscli/paramfile.py
+++ b/awscli/paramfile.py
@@ -24,6 +24,13 @@ class ResourceLoadingError(Exception):
     pass
 
 
+def register_init_uri_param_handler(event_emitter):
+    event_emitter.register(
+        'session-initialized',
+        register_uri_param_handler,
+    )
+
+
 def register_uri_param_handler(session, **kwargs):
     prefix_map = copy.deepcopy(LOCAL_PREFIX_MAP)
     handler = URIArgumentHandler(prefix_map)
diff --git a/tests/functional/test_handlers_registry.py b/tests/functional/test_handlers_registry.py
new file mode 100644
index 000000000000..7856fa3caf91
--- /dev/null
+++ b/tests/functional/test_handlers_registry.py
@@ -0,0 +1,155 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+import importlib
+from collections import OrderedDict
+
+import botocore.session
+
+from awscli.handlers_registry import PLUGIN_REGISTRY
+
+
+class _AuditEmitter:
+    """Minimal emitter that records event names without side effects."""
+
+    def __init__(self):
+        self.registrations = []
+
+    def register(self, event_name, *args, **kwargs):
+        self.registrations.append(event_name)
+
+    register_first = register
+    register_last = register
+
+
+class _CallbackCollector:
+    """Emitter that captures callbacks registered against a specific event."""
+
+    def __init__(self, target_event):
+        self._target_event = target_event
+        self.callbacks = []
+
+    def register(self, event_name, handler, *args, **kwargs):
+        if event_name == self._target_event:
+            self.callbacks.append(handler)
+
+    register_first = register
+    register_last = register
+
+
+def test_main_command_table_plugins_only_register_against_main():
+    """Plugins listed under building-command-table.main must not register
+    against any other events.
+
+    This invariant allows the lazy-loading system to skip importing these
+    plugin modules entirely and instead apply pre-computed renames and
+    LazyCommand additions from MAIN_COMMAND_TABLE_OPS.  If a plugin
+    mixes building-command-table.main registrations with other events,
+    split it into separate functions: one that only registers against
+    building-command-table.main, and another for the remaining events.
+    """
+    main_entries = PLUGIN_REGISTRY.get('building-command-table.main', [])
+    violations = []
+    for module_path, fn_name, entry_type in main_entries:
+        emitter = _AuditEmitter()
+        mod = importlib.import_module(module_path)
+        fn = getattr(mod, fn_name)
+        fn(emitter)
+        non_main = [
+            e
+            for e in emitter.registrations
+            if e != 'building-command-table.main'
+        ]
+        if non_main:
+            violations.append(
+                f'{module_path}.{fn_name} also registers against: '
+                f'{non_main}'
+            )
+    assert not violations, (
+        'The following building-command-table.main plugins register '
+        'against additional events. Split each into separate functions '
+        'so that the building-command-table.main function only registers '
+        'against that single event:\n'
+        + '\n'.join(f'  - {v}' for v in violations)
+    )
+
+
+def test_main_command_table_callbacks_only_add_or_rename():
+    """Callbacks registered against building-command-table.main must only
+    add new commands or rename existing ones.
+
+    MAIN_COMMAND_TABLE_OPS replaces these callbacks at runtime with
+    LazyCommand additions and direct renames.  If a callback also
+    modifies existing command table entries (e.g. changes properties on
+    a command object), that modification would be silently lost.
+    """
+    session = botocore.session.Session()
+    services = session.get_available_services()
+
+    main_entries = PLUGIN_REGISTRY.get('building-command-table.main', [])
+    violations = []
+
+    for module_path, fn_name, entry_type in main_entries:
+        collector = _CallbackCollector('building-command-table.main')
+        mod = importlib.import_module(module_path)
+        fn = getattr(mod, fn_name)
+        fn(collector)
+
+        for callback in collector.callbacks:
+            cb_name = f'{callback.__module__}.{callback.__qualname__}'
+
+            # Build a fresh command table for each callback.
+            class _Placeholder:
+                def __init__(self, name):
+                    self.name = name
+
+            command_table = OrderedDict()
+            for svc in services:
+                command_table[svc] = _Placeholder(svc)
+
+            snap_id_to_key = {id(v): k for k, v in command_table.items()}
+            snap_id_to_name = {id(v): v.name for k, v in command_table.items()}
+
+            callback(command_table=command_table, session=session)
+
+            # Classify every change.
+            new_id_to_key = {id(v): k for k, v in command_table.items()}
+            renamed_ids = set()
+
+            # Detect renames.
+            for obj_id, new_key in new_id_to_key.items():
+                old_key = snap_id_to_key.get(obj_id)
+                if old_key is not None and old_key != new_key:
+                    renamed_ids.add(obj_id)
+
+            # Detect modifications: an existing (non-renamed) entry whose
+            # .name property changed, or any entry that was removed.
+            for obj_id, old_key in snap_id_to_key.items():
+                if obj_id in renamed_ids:
+                    continue
+                if obj_id not in new_id_to_key:
+                    violations.append(f'{cb_name} removed command {old_key!r}')
+                    continue
+                new_key = new_id_to_key[obj_id]
+                cmd = command_table[new_key]
+                if cmd.name != snap_id_to_name[obj_id]:
+                    violations.append(
+                        f'{cb_name} modified .name on {new_key!r} '
+                        f'without renaming'
+                    )
+
+    assert not violations, (
+        'Callbacks registered against building-command-table.main must '
+        'only add or rename commands. The following callbacks perform '
+        'other modifications that would be lost when replaced by '
+        'MAIN_COMMAND_TABLE_OPS:\n' + '\n'.join(f'  - {v}' for v in violations)
+    )
diff --git a/tests/unit/customizations/s3/test_s3.py b/tests/unit/customizations/s3/test_s3.py
index 29f7fbf151b7..a8a4e4870178 100644
--- a/tests/unit/customizations/s3/test_s3.py
+++ b/tests/unit/customizations/s3/test_s3.py
@@ -10,7 +10,11 @@
 # distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
 # ANY KIND, either express or implied. See the License for the specific
 # language governing permissions and limitations under the License.
-from awscli.customizations.s3.s3 import add_s3, awscli_initialize
+from awscli.customizations.s3.s3 import (
+    add_s3,
+    register_s3_main,
+    register_s3_sync_strategies,
+)
 from awscli.testutils import BaseAWSCommandParamsTest, mock, unittest
 
 
@@ -24,7 +28,8 @@ def setUp(self):
         self.cli = mock.Mock()
 
     def test_initialize(self):
-        awscli_initialize(self.cli)
+        register_s3_main(self.cli)
+        register_s3_sync_strategies(self.cli)
         reference = []
         reference.append("building-command-table.main")
         reference.append("building-command-table.s3_sync")

From 975f57a9aa1b7f7d2ab1bb8e54e8dedb2db486fb Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 13 May 2026 14:24:34 -0400
Subject: [PATCH 07/21] Add handlers_registry.py which maps events to plugins
 and declares command-table operations.

---
 awscli/handlers_registry.py | 738 ++++++++++++++++++++++++++++++++++++
 1 file changed, 738 insertions(+)
 create mode 100644 awscli/handlers_registry.py

diff --git a/awscli/handlers_registry.py b/awscli/handlers_registry.py
new file mode 100644
index 000000000000..c20c40183f72
--- /dev/null
+++ b/awscli/handlers_registry.py
@@ -0,0 +1,738 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+"""Maps event patterns to initializer entries.
+
+At runtime, the LazyInitEmitter triggers entries on demand:
+before emitting event X, it finds entries whose event patterns
+match X, calls each init function at most once (passing the
+event_handlers emitter), then proceeds with normal event dispatch.
+
+Entry format:
+   (module, fn_name)    call fn(event_handlers)
+"""
+PLUGIN_REGISTRY = {
+    'after-call.data-pipeline.GetPipelineDefinition': [
+        ('awscli.customizations.datapipeline', 'register_customizations')
+    ],
+    'after-call.ecs.CreateExpressGatewayService': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'after-call.ecs.DeleteExpressGatewayService': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'after-call.ecs.UpdateExpressGatewayService': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'after-call.iam.CreateVirtualMFADevice': [
+        ('awscli.customizations.iamvirtmfa', 'IAMVMFAWrapper')
+    ],
+    'after-call.s3': [
+        ('awscli.customizations.s3errormsg', 'register_s3_error_msg')
+    ],
+    'before-building-argument-table-parser.ecs.create-express-gateway-service': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'before-building-argument-table-parser.ecs.delete-express-gateway-service': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'before-building-argument-table-parser.ecs.update-express-gateway-service': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'before-building-argument-table-parser.emr.*': [
+        ('awscli.customizations.emr.emr', 'emr_initialize')
+    ],
+    'before-parameter-build.ec2.BundleInstance': [
+        ('awscli.customizations.ec2.bundleinstance', 'register_bundleinstance')
+    ],
+    'before-parameter-build.ec2.CreateNetworkAclEntry': [
+        ('awscli.customizations.ec2.protocolarg', 'register_protocol_args')
+    ],
+    'before-parameter-build.ec2.ReplaceNetworkAclEntry': [
+        ('awscli.customizations.ec2.protocolarg', 'register_protocol_args')
+    ],
+    'before-parameter-build.ec2.RunInstances': [
+        ('awscli.customizations.ec2.addcount', 'register_count_events'),
+        ('awscli.customizations.ec2.runinstances', 'register_runinstances')
+    ],
+    'building-argument-table': [
+        ('awscli.customizations.cliinput', 'register_cli_input_args'),
+        ('awscli.customizations.paginate', 'register_pagination'),
+        ('awscli.customizations.generatecliskeleton', 'register_generate_cli_skeleton')
+    ],
+    'building-argument-table.*': [
+        ('awscli.customizations.streamingoutputarg', 'register_streaming_output_arg')
+    ],
+    'building-argument-table.apigateway.create-rest-api': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.apigatewayv2.create-api': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.apigatewayv2.update-api': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.clouddirectory.publish-schema': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.cloudfront.create-distribution': [
+        ('awscli.customizations.cloudfront', 'register')
+    ],
+    'building-argument-table.cloudfront.create-invalidation': [
+        ('awscli.customizations.cloudfront', 'register')
+    ],
+    'building-argument-table.cloudfront.update-distribution': [
+        ('awscli.customizations.cloudfront', 'register')
+    ],
+    'building-argument-table.cloudsearch.define-expression': [
+        ('awscli.customizations.cloudsearch', 'initialize')
+    ],
+    'building-argument-table.cloudsearch.define-index-field': [
+        ('awscli.customizations.cloudsearch', 'initialize')
+    ],
+    'building-argument-table.cloudsearchdomain.search': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.cloudsearchdomain.suggest': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.cloudwatch.put-metric-data': [
+        ('awscli.customizations.putmetricdata', 'register_put_metric_data')
+    ],
+    'building-argument-table.codepipeline.create-custom-action-type': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.codepipeline.delete-custom-action-type': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.codepipeline.get-action-type': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.codepipeline.get-pipeline': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.configservice.put-configuration-recorder': [
+        ('awscli.customizations.configservice.putconfigurationrecorder', 'register_modify_put_configuration_recorder')
+    ],
+    'building-argument-table.controltower.create-landing-zone': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.controltower.update-landing-zone': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.datapipeline.*': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.datapipeline.activate-pipeline': [
+        ('awscli.customizations.datapipeline', 'register_customizations')
+    ],
+    'building-argument-table.datapipeline.get-pipeline-definition': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.datapipeline.put-pipeline-definition': [
+        ('awscli.customizations.datapipeline', 'register_customizations')
+    ],
+    'building-argument-table.deploy.*': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.deploy.create-deployment': [
+        ('awscli.customizations.codedeploy.codedeploy', 'register_codedeploy')
+    ],
+    'building-argument-table.deploy.get-application-revision': [
+        ('awscli.customizations.codedeploy.codedeploy', 'register_codedeploy')
+    ],
+    'building-argument-table.deploy.register-application-revision': [
+        ('awscli.customizations.codedeploy.codedeploy', 'register_codedeploy')
+    ],
+    'building-argument-table.ec2.*': [
+        ('awscli.customizations.argrename', 'register_arg_renames'),
+        ('awscli.customizations.toplevelbool', 'register_bool_params')
+    ],
+    'building-argument-table.ec2.authorize-security-group-egress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'building-argument-table.ec2.authorize-security-group-ingress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'building-argument-table.ec2.bundle-instance': [
+        ('awscli.customizations.ec2.bundleinstance', 'register_bundleinstance')
+    ],
+    'building-argument-table.ec2.create-image': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.ec2.get-password-data': [
+        ('awscli.customizations.ec2.decryptpassword', 'register_ec2_add_priv_launch_key')
+    ],
+    'building-argument-table.ec2.revoke-security-group-egress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'building-argument-table.ec2.revoke-security-group-ingress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'building-argument-table.ec2.run-instances': [
+        ('awscli.customizations.ec2.addcount', 'register_count_events'),
+        ('awscli.customizations.ec2.runinstances', 'register_runinstances')
+    ],
+    'building-argument-table.ecs.*': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.ecs.create-express-gateway-service': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'building-argument-table.ecs.delete-express-gateway-service': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'building-argument-table.ecs.execute-command': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.ecs.update-express-gateway-service': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'building-argument-table.eks.create-cluster': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.eks.create-nodegroup': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.eks.update-cluster-components-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.eks.update-cluster-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.eks.update-nodegroup-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.elasticache.create-replication-group': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.emr.*': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.emr.add-tags': [
+        ('awscli.customizations.emr.emr', 'emr_initialize')
+    ],
+    'building-argument-table.emr.list-clusters': [
+        ('awscli.customizations.emr.emr', 'emr_initialize')
+    ],
+    'building-argument-table.gamelift.create-build': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.gamelift.create-script': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.gamelift.update-build': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.gamelift.update-script': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.glue.get-unfiltered-partition-metadata': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.glue.get-unfiltered-partitions-metadata': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.glue.get-unfiltered-table-metadata': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.iam.create-virtual-mfa-device': [
+        ('awscli.customizations.iamvirtmfa', 'IAMVMFAWrapper')
+    ],
+    'building-argument-table.iot.create-certificate-from-csr': [
+        ('awscli.customizations.iot', 'register_iot_create_keys_from_csr')
+    ],
+    'building-argument-table.iot.create-keys-and-certificate': [
+        ('awscli.customizations.iot', 'register_iot_create_keys_and_cert_args')
+    ],
+    'building-argument-table.iotwireless.*': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.kinesis.list-streams': [
+        ('awscli.customizations.kinesis', 'register_kinesis_list_streams_pagination_backcompat')
+    ],
+    'building-argument-table.kinesisanalytics.add-application-output': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.kinesisanalyticsv2.add-application-output': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.lambda.create-function': [
+        ('awscli.customizations.awslambda', 'register_lambda_create_function')
+    ],
+    'building-argument-table.lambda.publish-layer-version': [
+        ('awscli.customizations.awslambda', 'register_lambda_create_function')
+    ],
+    'building-argument-table.lambda.update-function-code': [
+        ('awscli.customizations.awslambda', 'register_lambda_create_function')
+    ],
+    'building-argument-table.lex-models.delete-bot': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.lex-models.delete-bot-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.lex-models.delete-intent': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.lex-models.delete-intent-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.lex-models.delete-slot-type': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.lex-models.delete-slot-type-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.lex-models.get-export': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.lex-models.get-intent': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.lex-models.get-slot-type': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.license-manager.delete-grant': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.license-manager.get-grant': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.license-manager.get-license': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.mgn.*': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.mturk.list-qualification-types': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.delete-email-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.delete-in-app-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.delete-push-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.delete-sms-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.delete-voice-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.get-campaign-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.get-email-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.get-in-app-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.get-push-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.get-segment-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.get-sms-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.get-voice-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.update-email-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.update-in-app-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.update-push-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.update-sms-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.pinpoint.update-voice-template': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.quicksight.start-asset-bundle-import-job': [
+        ('awscli.customizations.quicksight', 'register_quicksight_asset_bundle_customizations')
+    ],
+    'building-argument-table.rds.add-option-to-option-group': [
+        ('awscli.customizations.rds', 'register_rds_modify_split')
+    ],
+    'building-argument-table.rds.remove-option-from-option-group': [
+        ('awscli.customizations.rds', 'register_rds_modify_split')
+    ],
+    'building-argument-table.rekognition.*': [
+        ('awscli.customizations.rekognition', 'register_rekognition_detect_labels')
+    ],
+    'building-argument-table.rekognition.compare-faces': [
+        ('awscli.customizations.rekognition', 'register_rekognition_detect_labels')
+    ],
+    'building-argument-table.rekognition.create-stream-processor': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.route53.delete-traffic-policy': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.route53.get-traffic-policy': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.route53.update-traffic-policy-comment': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.route53domains.view-billing': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.s3api.select-object-content': [
+        ('awscli.customizations.s3events', 'register_event_stream_arg')
+    ],
+    'building-argument-table.sagemaker.delete-image-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.sagemaker.describe-image-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.sagemaker.list-aliases': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.sagemaker.update-image-version': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.schemas.*': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.ses.send-email': [
+        ('awscli.customizations.sessendemail', 'register_ses_send_email')
+    ],
+    'building-argument-table.sns.subscribe': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.stepfunctions.send-task-success': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.swf.register-activity-type': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.swf.register-workflow-type': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.translate.import-terminology': [
+        ('awscli.customizations.translate', 'register_translate_import_terminology')
+    ],
+    'building-argument-table.translate.translate-document': [
+        ('awscli.customizations.translate', 'register_translate_import_terminology')
+    ],
+    'building-argument-table.workdocs.create-notification-subscription': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-argument-table.workdocs.describe-users': [
+        ('awscli.customizations.argrename', 'register_arg_renames')
+    ],
+    'building-command-table': [
+        ('awscli.customizations.waiters', 'register_add_waiters'),
+        ('awscli.alias', 'register_alias_commands')
+    ],
+    'building-command-table.bedrock-agent-runtime': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.bedrock-agentcore': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.bedrock-runtime': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.cli-dev': [
+        ('awscli.customizations.wizard.commands', 'register_wizard_commands')
+    ],
+    'building-command-table.cloudformation': [
+        ('awscli.customizations.cloudformation', 'initialize')
+    ],
+    'building-command-table.cloudfront': [
+        ('awscli.customizations.cloudfront', 'register')
+    ],
+    'building-command-table.cloudtrail': [
+        ('awscli.customizations.cloudtrail', 'initialize')
+    ],
+    'building-command-table.cloudwatch': [
+        ('awscli.customizations.cloudwatch', 'register_rename_otel_commands')
+    ],
+    'building-command-table.codeartifact': [
+        ('awscli.customizations.codeartifact', 'register_codeartifact_commands')
+    ],
+    'building-command-table.codecommit': [
+        ('awscli.customizations.codecommit', 'initialize')
+    ],
+    'building-command-table.configservice': [
+        ('awscli.customizations.configservice.subscribe', 'register_subscribe'),
+        ('awscli.customizations.configservice.getstatus', 'register_get_status')
+    ],
+    'building-command-table.configure': [
+        ('awscli.customizations.wizard.commands', 'register_wizard_commands')
+    ],
+    'building-command-table.connecthealth': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.datapipeline': [
+        ('awscli.customizations.datapipeline', 'register_customizations')
+    ],
+    'building-command-table.deploy': [
+        ('awscli.customizations.codedeploy.codedeploy', 'register_codedeploy')
+    ],
+    'building-command-table.devops-agent': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.dlm': [
+        ('awscli.customizations.dlm.dlm', 'dlm_initialize')
+    ],
+    'building-command-table.dsql': [
+        ('awscli.customizations.dsql', 'register_dsql_customizations')
+    ],
+    'building-command-table.dynamodb': [
+        ('awscli.customizations.wizard.commands', 'register_wizard_commands')
+    ],
+    'building-command-table.ec2': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.ec2-instance-connect': [
+        ('awscli.customizations.ec2instanceconnect', 'register_ec2_instance_connect_commands')
+    ],
+    'building-command-table.ecr': [
+        ('awscli.customizations.ecr', 'register_ecr_commands')
+    ],
+    'building-command-table.ecr-public': [
+        ('awscli.customizations.ecr_public', 'register_ecr_public_commands')
+    ],
+    'building-command-table.ecs': [
+        ('awscli.customizations.ecs', 'initialize')
+    ],
+    'building-command-table.eks': [
+        ('awscli.customizations.eks', 'initialize')
+    ],
+    'building-command-table.emr': [
+        ('awscli.customizations.removals', 'register_removals'),
+        ('awscli.customizations.emr.emr', 'emr_initialize')
+    ],
+    'building-command-table.emr-containers': [
+        ('awscli.customizations.emrcontainers', 'initialize')
+    ],
+    'building-command-table.events': [
+        ('awscli.customizations.wizard.commands', 'register_wizard_commands')
+    ],
+    'building-command-table.gamelift': [
+        ('awscli.customizations.gamelift', 'register_gamelift_commands')
+    ],
+    'building-command-table.iam': [
+        ('awscli.customizations.wizard.commands', 'register_wizard_commands')
+    ],
+    'building-command-table.iotsitewise': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.kinesis': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.lambda': [
+        ('awscli.customizations.removals', 'register_removals'),
+        ('awscli.customizations.wizard.commands', 'register_wizard_commands')
+    ],
+    'building-command-table.lexv2-runtime': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.lightsail': [
+        ('awscli.customizations.lightsail', 'initialize')
+    ],
+    'building-command-table.logs': [
+        ('awscli.customizations.removals', 'register_removals'),
+        ('awscli.customizations.logs', 'register_logs_commands')
+    ],
+    'building-command-table.main': [
+        ('awscli.customizations.s3.s3', 'register_s3_main'),
+        ('awscli.customizations.dynamodb.ddb', 'register_ddb'),
+        ('awscli.customizations.configure.configure', 'register_configure_cmd'),
+        ('awscli.customizations.codedeploy.codedeploy', 'register_rename_codedeploy'),
+        ('awscli.customizations.configservice.rename_cmd', 'register_rename_config'),
+        ('awscli.customizations.history', 'register_history_commands'),
+        ('awscli.customizations.devcommands', 'register_dev_commands'),
+        ('awscli.customizations.login', 'register_login_cmds')
+    ],
+    'building-command-table.polly': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.qbusiness': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.rds': [
+        ('awscli.customizations.rds', 'register_rds_modify_split'),
+        ('awscli.customizations.rds', 'register_add_generate_db_auth_token')
+    ],
+    'building-command-table.s3_sync': [
+        ('awscli.customizations.s3.s3', 'register_s3_sync_strategies')
+    ],
+    'building-command-table.sagemaker-runtime': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.servicecatalog': [
+        ('awscli.customizations.servicecatalog', 'register_servicecatalog_commands')
+    ],
+    'building-command-table.ses': [
+        ('awscli.customizations.removals', 'register_removals')
+    ],
+    'building-command-table.ssm': [
+        ('awscli.customizations.sessionmanager', 'register_ssm_session')
+    ],
+    'building-command-table.sso': [
+        ('awscli.customizations.sso', 'register_sso_commands')
+    ],
+    'calling-command.cloudsearchdomain': [
+        ('awscli.customizations.cloudsearchdomain', 'register_cloudsearchdomain')
+    ],
+    'calling-command.dynamodb.*': [
+        ('awscli.customizations.dynamodb.paginatorfix', 'register_dynamodb_paginator_fix')
+    ],
+    'calling-command.ec2.describe-snapshots': [
+        ('awscli.customizations.ec2.paginate', 'register_ec2_page_size_injector')
+    ],
+    'calling-command.ec2.describe-volumes': [
+        ('awscli.customizations.ec2.paginate', 'register_ec2_page_size_injector')
+    ],
+    'doc-description': [
+        ('awscli.customizations.paginate', 'register_pagination')
+    ],
+    'doc-description.ec2.authorize-security-group-egress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'doc-description.ec2.authorize-security-group-ingress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'doc-description.ec2.revoke-security-group-ingress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'doc-description.ec2.revoke-security-groupdoc-ingress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'doc-description.iot-data': [
+        ('awscli.customizations.iot_data', 'register_custom_endpoint_note')
+    ],
+    'doc-examples.*.*': [
+        ('awscli.customizations.addexamples', 'register_docs_add_examples')
+    ],
+    'doc-option.route53.create-hosted-zone.hosted-zone-config': [
+        ('awscli.customizations.route53', 'register_create_hosted_zone_doc_fix')
+    ],
+    'doc-output.datapipeline.get-pipeline-definition': [
+        ('awscli.customizations.datapipeline', 'register_customizations')
+    ],
+    'doc-output.s3api': [
+        ('awscli.customizations.s3events', 'register_document_expires_string')
+    ],
+    'doc-output.s3api.select-object-content': [
+        ('awscli.customizations.s3events', 'register_event_stream_arg')
+    ],
+    'doc-title.kms.create-grant': [
+        ('awscli.customizations.kms', 'register_fix_kms_create_grant_docs')
+    ],
+    'operation-args-parsed.cloudfront.create-distribution': [
+        ('awscli.customizations.cloudfront', 'register')
+    ],
+    'operation-args-parsed.cloudfront.create-invalidation': [
+        ('awscli.customizations.cloudfront', 'register')
+    ],
+    'operation-args-parsed.cloudfront.update-distribution': [
+        ('awscli.customizations.cloudfront', 'register')
+    ],
+    'operation-args-parsed.cloudwatch.put-metric-data': [
+        ('awscli.customizations.putmetricdata', 'register_put_metric_data')
+    ],
+    'operation-args-parsed.ec2.authorize-security-group-egress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'operation-args-parsed.ec2.authorize-security-group-ingress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'operation-args-parsed.ec2.bundle-instance': [
+        ('awscli.customizations.ec2.bundleinstance', 'register_bundleinstance')
+    ],
+    'operation-args-parsed.ec2.revoke-security-group-egress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'operation-args-parsed.ec2.revoke-security-group-ingress': [
+        ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
+    ],
+    'operation-args-parsed.ec2.run-instances': [
+        ('awscli.customizations.ec2.runinstances', 'register_runinstances')
+    ],
+    'operation-args-parsed.ecs.create-express-gateway-service': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'operation-args-parsed.ecs.delete-express-gateway-service': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'operation-args-parsed.ecs.update-express-gateway-service': [
+        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+    ],
+    'operation-args-parsed.kinesis.list-streams': [
+        ('awscli.customizations.kinesis', 'register_kinesis_list_streams_pagination_backcompat')
+    ],
+    'operation-args-parsed.ses.send-email': [
+        ('awscli.customizations.sessendemail', 'register_ses_send_email')
+    ],
+    'process-cli-arg': [
+        ('awscli.argprocess', 'register_param_shorthand_parser')
+    ],
+    'process-cli-arg.lambda.update-function-code': [
+        ('awscli.customizations.awslambda', 'register_lambda_create_function')
+    ],
+    'session-initialized': [
+        ('awscli.paramfile', 'register_init_uri_param_handler'),
+        ('awscli.customizations.binaryformat', 'register_init_binary_formatter'),
+        ('awscli.clidriver', 'register_no_pager_handler'),
+        ('awscli.customizations.assumerole', 'register_assume_role_provider'),
+        ('awscli.customizations.timestampformat', 'register_timestamp_format'),
+        ('awscli.customizations.history', 'register_history_mode'),
+        ('awscli.customizations.sso', 'register_sso_commands')
+    ],
+    'top-level-args-parsed': [
+        ('awscli.customizations.globalargs', 'register_parse_global_args'),
+        ('awscli.customizations.cloudfront', 'register')
+    ]
+}
+
+# Declarative model of changes made to the command table by plugins
+# that register against building-command-table.main.
+#
+# At runtime, plugins listed in building-command-table.main above
+# are NOT called as init functions. Instead, these pre-computed
+# operations are applied directly, allowing added commands to be
+# wrapped in LazyCommand and deferring heavy module imports until
+# the command is actually invoked.
+#
+# Entry formats:
+#   ('rename', old_name, new_name)
+#   ('add', cmd_name, cmd_module, cmd_class)
+
+MAIN_COMMAND_TABLE_OPS = [
+    ('rename', 's3', 's3api'),
+    ('add', 's3', 'awscli.customizations.s3.s3', 'S3'),
+    ('add', 'ddb', 'awscli.customizations.dynamodb.ddb', 'DDB'),
+    ('add', 'configure', 'awscli.customizations.configure.configure', 'ConfigureCommand'),
+    ('rename', 'codedeploy', 'deploy'),
+    ('rename', 'config', 'configservice'),
+    ('add', 'history', 'awscli.customizations.history', 'HistoryCommand'),
+    ('add', 'cli-dev', 'awscli.customizations.devcommands', 'CLIDevCommand'),
+    ('add', 'login', 'awscli.customizations.login.login', 'LoginCommand'),
+    ('add', 'logout', 'awscli.customizations.login.logout', 'LogoutCommand'),
+]

From 75d5343c8bc95c40d2fdd3824fadeb4247290c41 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 13 May 2026 14:25:16 -0400
Subject: [PATCH 08/21] Formatting.

---
 awscli/customizations/addexamples.py |   1 -
 awscli/handlers.py                   |  10 +-
 awscli/handlers_registry.py          | 217 +++++++++++++++++++++------
 3 files changed, 174 insertions(+), 54 deletions(-)

diff --git a/awscli/customizations/addexamples.py b/awscli/customizations/addexamples.py
index 9ccf670ec6e8..5e91cc547aed 100644
--- a/awscli/customizations/addexamples.py
+++ b/awscli/customizations/addexamples.py
@@ -34,7 +34,6 @@
 
 
 def register_docs_add_examples(event_emitter):
-
     # The following will get fired for every option we are
     # documenting.  It will attempt to add an example_fn on to
     # the parameter object if the parameter supports shorthand
diff --git a/awscli/handlers.py b/awscli/handlers.py
index bc5234a4a7f9..2dab06ba171a 100644
--- a/awscli/handlers.py
+++ b/awscli/handlers.py
@@ -39,6 +39,8 @@
 from awscli.customizations.codecommit import initialize as codecommit_init
 from awscli.customizations.codedeploy.codedeploy import (
     register_codedeploy,
+)
+from awscli.customizations.codedeploy.codedeploy import (
     register_rename_codedeploy as codedeploy_init,
 )
 from awscli.customizations.configservice.getstatus import register_get_status
@@ -60,7 +62,7 @@
 from awscli.customizations.ec2.addcount import register_count_events
 from awscli.customizations.ec2.bundleinstance import register_bundleinstance
 from awscli.customizations.ec2.decryptpassword import (
-    register_ec2_add_priv_launch_key
+    register_ec2_add_priv_launch_key,
 )
 from awscli.customizations.ec2.paginate import register_ec2_page_size_injector
 from awscli.customizations.ec2.protocolarg import register_protocol_args
@@ -118,7 +120,7 @@
 from awscli.customizations.route53 import register_create_hosted_zone_doc_fix
 from awscli.customizations.s3.s3 import (
     register_s3_main,
-    register_s3_sync_strategies
+    register_s3_sync_strategies,
 )
 from awscli.customizations.s3errormsg import register_s3_error_msg
 from awscli.customizations.s3events import (
@@ -131,7 +133,9 @@
 from awscli.customizations.sessendemail import register_ses_send_email
 from awscli.customizations.sessionmanager import register_ssm_session
 from awscli.customizations.sso import register_sso_commands
-from awscli.customizations.streamingoutputarg import register_streaming_output_arg
+from awscli.customizations.streamingoutputarg import (
+    register_streaming_output_arg,
+)
 from awscli.customizations.timestampformat import register_timestamp_format
 from awscli.customizations.toplevelbool import register_bool_params
 from awscli.customizations.translate import (
diff --git a/awscli/handlers_registry.py b/awscli/handlers_registry.py
index c20c40183f72..0aa2bef59223 100644
--- a/awscli/handlers_registry.py
+++ b/awscli/handlers_registry.py
@@ -20,18 +20,28 @@
 Entry format:
    (module, fn_name)    call fn(event_handlers)
 """
+
 PLUGIN_REGISTRY = {
     'after-call.data-pipeline.GetPipelineDefinition': [
         ('awscli.customizations.datapipeline', 'register_customizations')
     ],
     'after-call.ecs.CreateExpressGatewayService': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'after-call.ecs.DeleteExpressGatewayService': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'after-call.ecs.UpdateExpressGatewayService': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'after-call.iam.CreateVirtualMFADevice': [
         ('awscli.customizations.iamvirtmfa', 'IAMVMFAWrapper')
@@ -40,13 +50,22 @@
         ('awscli.customizations.s3errormsg', 'register_s3_error_msg')
     ],
     'before-building-argument-table-parser.ecs.create-express-gateway-service': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'before-building-argument-table-parser.ecs.delete-express-gateway-service': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'before-building-argument-table-parser.ecs.update-express-gateway-service': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'before-building-argument-table-parser.emr.*': [
         ('awscli.customizations.emr.emr', 'emr_initialize')
@@ -62,15 +81,21 @@
     ],
     'before-parameter-build.ec2.RunInstances': [
         ('awscli.customizations.ec2.addcount', 'register_count_events'),
-        ('awscli.customizations.ec2.runinstances', 'register_runinstances')
+        ('awscli.customizations.ec2.runinstances', 'register_runinstances'),
     ],
     'building-argument-table': [
         ('awscli.customizations.cliinput', 'register_cli_input_args'),
         ('awscli.customizations.paginate', 'register_pagination'),
-        ('awscli.customizations.generatecliskeleton', 'register_generate_cli_skeleton')
+        (
+            'awscli.customizations.generatecliskeleton',
+            'register_generate_cli_skeleton',
+        ),
     ],
     'building-argument-table.*': [
-        ('awscli.customizations.streamingoutputarg', 'register_streaming_output_arg')
+        (
+            'awscli.customizations.streamingoutputarg',
+            'register_streaming_output_arg',
+        )
     ],
     'building-argument-table.apigateway.create-rest-api': [
         ('awscli.customizations.argrename', 'register_arg_renames')
@@ -121,7 +146,10 @@
         ('awscli.customizations.argrename', 'register_arg_renames')
     ],
     'building-argument-table.configservice.put-configuration-recorder': [
-        ('awscli.customizations.configservice.putconfigurationrecorder', 'register_modify_put_configuration_recorder')
+        (
+            'awscli.customizations.configservice.putconfigurationrecorder',
+            'register_modify_put_configuration_recorder',
+        )
     ],
     'building-argument-table.controltower.create-landing-zone': [
         ('awscli.customizations.argrename', 'register_arg_renames')
@@ -155,7 +183,7 @@
     ],
     'building-argument-table.ec2.*': [
         ('awscli.customizations.argrename', 'register_arg_renames'),
-        ('awscli.customizations.toplevelbool', 'register_bool_params')
+        ('awscli.customizations.toplevelbool', 'register_bool_params'),
     ],
     'building-argument-table.ec2.authorize-security-group-egress': [
         ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
@@ -170,7 +198,10 @@
         ('awscli.customizations.argrename', 'register_arg_renames')
     ],
     'building-argument-table.ec2.get-password-data': [
-        ('awscli.customizations.ec2.decryptpassword', 'register_ec2_add_priv_launch_key')
+        (
+            'awscli.customizations.ec2.decryptpassword',
+            'register_ec2_add_priv_launch_key',
+        )
     ],
     'building-argument-table.ec2.revoke-security-group-egress': [
         ('awscli.customizations.ec2.secgroupsimplify', 'register_secgroup')
@@ -180,22 +211,31 @@
     ],
     'building-argument-table.ec2.run-instances': [
         ('awscli.customizations.ec2.addcount', 'register_count_events'),
-        ('awscli.customizations.ec2.runinstances', 'register_runinstances')
+        ('awscli.customizations.ec2.runinstances', 'register_runinstances'),
     ],
     'building-argument-table.ecs.*': [
         ('awscli.customizations.argrename', 'register_arg_renames')
     ],
     'building-argument-table.ecs.create-express-gateway-service': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'building-argument-table.ecs.delete-express-gateway-service': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'building-argument-table.ecs.execute-command': [
         ('awscli.customizations.argrename', 'register_arg_renames')
     ],
     'building-argument-table.ecs.update-express-gateway-service': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'building-argument-table.eks.create-cluster': [
         ('awscli.customizations.argrename', 'register_arg_renames')
@@ -258,7 +298,10 @@
         ('awscli.customizations.argrename', 'register_arg_renames')
     ],
     'building-argument-table.kinesis.list-streams': [
-        ('awscli.customizations.kinesis', 'register_kinesis_list_streams_pagination_backcompat')
+        (
+            'awscli.customizations.kinesis',
+            'register_kinesis_list_streams_pagination_backcompat',
+        )
     ],
     'building-argument-table.kinesisanalytics.add-application-output': [
         ('awscli.customizations.argrename', 'register_arg_renames')
@@ -369,7 +412,10 @@
         ('awscli.customizations.argrename', 'register_arg_renames')
     ],
     'building-argument-table.quicksight.start-asset-bundle-import-job': [
-        ('awscli.customizations.quicksight', 'register_quicksight_asset_bundle_customizations')
+        (
+            'awscli.customizations.quicksight',
+            'register_quicksight_asset_bundle_customizations',
+        )
     ],
     'building-argument-table.rds.add-option-to-option-group': [
         ('awscli.customizations.rds', 'register_rds_modify_split')
@@ -378,10 +424,16 @@
         ('awscli.customizations.rds', 'register_rds_modify_split')
     ],
     'building-argument-table.rekognition.*': [
-        ('awscli.customizations.rekognition', 'register_rekognition_detect_labels')
+        (
+            'awscli.customizations.rekognition',
+            'register_rekognition_detect_labels',
+        )
     ],
     'building-argument-table.rekognition.compare-faces': [
-        ('awscli.customizations.rekognition', 'register_rekognition_detect_labels')
+        (
+            'awscli.customizations.rekognition',
+            'register_rekognition_detect_labels',
+        )
     ],
     'building-argument-table.rekognition.create-stream-processor': [
         ('awscli.customizations.argrename', 'register_arg_renames')
@@ -432,10 +484,16 @@
         ('awscli.customizations.argrename', 'register_arg_renames')
     ],
     'building-argument-table.translate.import-terminology': [
-        ('awscli.customizations.translate', 'register_translate_import_terminology')
+        (
+            'awscli.customizations.translate',
+            'register_translate_import_terminology',
+        )
     ],
     'building-argument-table.translate.translate-document': [
-        ('awscli.customizations.translate', 'register_translate_import_terminology')
+        (
+            'awscli.customizations.translate',
+            'register_translate_import_terminology',
+        )
     ],
     'building-argument-table.workdocs.create-notification-subscription': [
         ('awscli.customizations.argrename', 'register_arg_renames')
@@ -445,7 +503,7 @@
     ],
     'building-command-table': [
         ('awscli.customizations.waiters', 'register_add_waiters'),
-        ('awscli.alias', 'register_alias_commands')
+        ('awscli.alias', 'register_alias_commands'),
     ],
     'building-command-table.bedrock-agent-runtime': [
         ('awscli.customizations.removals', 'register_removals')
@@ -472,14 +530,23 @@
         ('awscli.customizations.cloudwatch', 'register_rename_otel_commands')
     ],
     'building-command-table.codeartifact': [
-        ('awscli.customizations.codeartifact', 'register_codeartifact_commands')
+        (
+            'awscli.customizations.codeartifact',
+            'register_codeartifact_commands',
+        )
     ],
     'building-command-table.codecommit': [
         ('awscli.customizations.codecommit', 'initialize')
     ],
     'building-command-table.configservice': [
-        ('awscli.customizations.configservice.subscribe', 'register_subscribe'),
-        ('awscli.customizations.configservice.getstatus', 'register_get_status')
+        (
+            'awscli.customizations.configservice.subscribe',
+            'register_subscribe',
+        ),
+        (
+            'awscli.customizations.configservice.getstatus',
+            'register_get_status',
+        ),
     ],
     'building-command-table.configure': [
         ('awscli.customizations.wizard.commands', 'register_wizard_commands')
@@ -509,7 +576,10 @@
         ('awscli.customizations.removals', 'register_removals')
     ],
     'building-command-table.ec2-instance-connect': [
-        ('awscli.customizations.ec2instanceconnect', 'register_ec2_instance_connect_commands')
+        (
+            'awscli.customizations.ec2instanceconnect',
+            'register_ec2_instance_connect_commands',
+        )
     ],
     'building-command-table.ecr': [
         ('awscli.customizations.ecr', 'register_ecr_commands')
@@ -525,7 +595,7 @@
     ],
     'building-command-table.emr': [
         ('awscli.customizations.removals', 'register_removals'),
-        ('awscli.customizations.emr.emr', 'emr_initialize')
+        ('awscli.customizations.emr.emr', 'emr_initialize'),
     ],
     'building-command-table.emr-containers': [
         ('awscli.customizations.emrcontainers', 'initialize')
@@ -547,7 +617,7 @@
     ],
     'building-command-table.lambda': [
         ('awscli.customizations.removals', 'register_removals'),
-        ('awscli.customizations.wizard.commands', 'register_wizard_commands')
+        ('awscli.customizations.wizard.commands', 'register_wizard_commands'),
     ],
     'building-command-table.lexv2-runtime': [
         ('awscli.customizations.removals', 'register_removals')
@@ -557,17 +627,26 @@
     ],
     'building-command-table.logs': [
         ('awscli.customizations.removals', 'register_removals'),
-        ('awscli.customizations.logs', 'register_logs_commands')
+        ('awscli.customizations.logs', 'register_logs_commands'),
     ],
     'building-command-table.main': [
         ('awscli.customizations.s3.s3', 'register_s3_main'),
         ('awscli.customizations.dynamodb.ddb', 'register_ddb'),
-        ('awscli.customizations.configure.configure', 'register_configure_cmd'),
-        ('awscli.customizations.codedeploy.codedeploy', 'register_rename_codedeploy'),
-        ('awscli.customizations.configservice.rename_cmd', 'register_rename_config'),
+        (
+            'awscli.customizations.configure.configure',
+            'register_configure_cmd',
+        ),
+        (
+            'awscli.customizations.codedeploy.codedeploy',
+            'register_rename_codedeploy',
+        ),
+        (
+            'awscli.customizations.configservice.rename_cmd',
+            'register_rename_config',
+        ),
         ('awscli.customizations.history', 'register_history_commands'),
         ('awscli.customizations.devcommands', 'register_dev_commands'),
-        ('awscli.customizations.login', 'register_login_cmds')
+        ('awscli.customizations.login', 'register_login_cmds'),
     ],
     'building-command-table.polly': [
         ('awscli.customizations.removals', 'register_removals')
@@ -577,7 +656,7 @@
     ],
     'building-command-table.rds': [
         ('awscli.customizations.rds', 'register_rds_modify_split'),
-        ('awscli.customizations.rds', 'register_add_generate_db_auth_token')
+        ('awscli.customizations.rds', 'register_add_generate_db_auth_token'),
     ],
     'building-command-table.s3_sync': [
         ('awscli.customizations.s3.s3', 'register_s3_sync_strategies')
@@ -586,7 +665,10 @@
         ('awscli.customizations.removals', 'register_removals')
     ],
     'building-command-table.servicecatalog': [
-        ('awscli.customizations.servicecatalog', 'register_servicecatalog_commands')
+        (
+            'awscli.customizations.servicecatalog',
+            'register_servicecatalog_commands',
+        )
     ],
     'building-command-table.ses': [
         ('awscli.customizations.removals', 'register_removals')
@@ -598,16 +680,28 @@
         ('awscli.customizations.sso', 'register_sso_commands')
     ],
     'calling-command.cloudsearchdomain': [
-        ('awscli.customizations.cloudsearchdomain', 'register_cloudsearchdomain')
+        (
+            'awscli.customizations.cloudsearchdomain',
+            'register_cloudsearchdomain',
+        )
     ],
     'calling-command.dynamodb.*': [
-        ('awscli.customizations.dynamodb.paginatorfix', 'register_dynamodb_paginator_fix')
+        (
+            'awscli.customizations.dynamodb.paginatorfix',
+            'register_dynamodb_paginator_fix',
+        )
     ],
     'calling-command.ec2.describe-snapshots': [
-        ('awscli.customizations.ec2.paginate', 'register_ec2_page_size_injector')
+        (
+            'awscli.customizations.ec2.paginate',
+            'register_ec2_page_size_injector',
+        )
     ],
     'calling-command.ec2.describe-volumes': [
-        ('awscli.customizations.ec2.paginate', 'register_ec2_page_size_injector')
+        (
+            'awscli.customizations.ec2.paginate',
+            'register_ec2_page_size_injector',
+        )
     ],
     'doc-description': [
         ('awscli.customizations.paginate', 'register_pagination')
@@ -631,7 +725,10 @@
         ('awscli.customizations.addexamples', 'register_docs_add_examples')
     ],
     'doc-option.route53.create-hosted-zone.hosted-zone-config': [
-        ('awscli.customizations.route53', 'register_create_hosted_zone_doc_fix')
+        (
+            'awscli.customizations.route53',
+            'register_create_hosted_zone_doc_fix',
+        )
     ],
     'doc-output.datapipeline.get-pipeline-definition': [
         ('awscli.customizations.datapipeline', 'register_customizations')
@@ -676,16 +773,28 @@
         ('awscli.customizations.ec2.runinstances', 'register_runinstances')
     ],
     'operation-args-parsed.ecs.create-express-gateway-service': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'operation-args-parsed.ecs.delete-express-gateway-service': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'operation-args-parsed.ecs.update-express-gateway-service': [
-        ('awscli.customizations.ecs.monitormutatinggatewayservice', 'register_monitor_mutating_gateway_service')
+        (
+            'awscli.customizations.ecs.monitormutatinggatewayservice',
+            'register_monitor_mutating_gateway_service',
+        )
     ],
     'operation-args-parsed.kinesis.list-streams': [
-        ('awscli.customizations.kinesis', 'register_kinesis_list_streams_pagination_backcompat')
+        (
+            'awscli.customizations.kinesis',
+            'register_kinesis_list_streams_pagination_backcompat',
+        )
     ],
     'operation-args-parsed.ses.send-email': [
         ('awscli.customizations.sessendemail', 'register_ses_send_email')
@@ -698,17 +807,20 @@
     ],
     'session-initialized': [
         ('awscli.paramfile', 'register_init_uri_param_handler'),
-        ('awscli.customizations.binaryformat', 'register_init_binary_formatter'),
+        (
+            'awscli.customizations.binaryformat',
+            'register_init_binary_formatter',
+        ),
         ('awscli.clidriver', 'register_no_pager_handler'),
         ('awscli.customizations.assumerole', 'register_assume_role_provider'),
         ('awscli.customizations.timestampformat', 'register_timestamp_format'),
         ('awscli.customizations.history', 'register_history_mode'),
-        ('awscli.customizations.sso', 'register_sso_commands')
+        ('awscli.customizations.sso', 'register_sso_commands'),
     ],
     'top-level-args-parsed': [
         ('awscli.customizations.globalargs', 'register_parse_global_args'),
-        ('awscli.customizations.cloudfront', 'register')
-    ]
+        ('awscli.customizations.cloudfront', 'register'),
+    ],
 }
 
 # Declarative model of changes made to the command table by plugins
@@ -728,7 +840,12 @@
     ('rename', 's3', 's3api'),
     ('add', 's3', 'awscli.customizations.s3.s3', 'S3'),
     ('add', 'ddb', 'awscli.customizations.dynamodb.ddb', 'DDB'),
-    ('add', 'configure', 'awscli.customizations.configure.configure', 'ConfigureCommand'),
+    (
+        'add',
+        'configure',
+        'awscli.customizations.configure.configure',
+        'ConfigureCommand',
+    ),
     ('rename', 'codedeploy', 'deploy'),
     ('rename', 'config', 'configservice'),
     ('add', 'history', 'awscli.customizations.history', 'HistoryCommand'),

From 511d6cbdf080725c4dbce6aade0263af9b2bef94 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 13 May 2026 14:39:27 -0400
Subject: [PATCH 09/21] Update test_handlers_registry against the simplified
 format of handlers_registry.

---
 tests/functional/test_handlers_registry.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/functional/test_handlers_registry.py b/tests/functional/test_handlers_registry.py
index 7856fa3caf91..97b53f2097dc 100644
--- a/tests/functional/test_handlers_registry.py
+++ b/tests/functional/test_handlers_registry.py
@@ -59,7 +59,7 @@ def test_main_command_table_plugins_only_register_against_main():
     """
     main_entries = PLUGIN_REGISTRY.get('building-command-table.main', [])
     violations = []
-    for module_path, fn_name, entry_type in main_entries:
+    for module_path, fn_name in main_entries:
         emitter = _AuditEmitter()
         mod = importlib.import_module(module_path)
         fn = getattr(mod, fn_name)
@@ -98,7 +98,7 @@ def test_main_command_table_callbacks_only_add_or_rename():
     main_entries = PLUGIN_REGISTRY.get('building-command-table.main', [])
     violations = []
 
-    for module_path, fn_name, entry_type in main_entries:
+    for module_path, fn_name in main_entries:
         collector = _CallbackCollector('building-command-table.main')
         mod = importlib.import_module(module_path)
         fn = getattr(mod, fn_name)

From 11b07cde48c721a200cafc3b3b51a7d8418fc546 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 13 May 2026 15:04:20 -0400
Subject: [PATCH 10/21] Add new functional tests to assert that all modules
 referenced in handlers_registry.py are importable.

---
 tests/functional/test_handlers_registry.py | 59 +++++++++++++++++++++-
 1 file changed, 58 insertions(+), 1 deletion(-)

diff --git a/tests/functional/test_handlers_registry.py b/tests/functional/test_handlers_registry.py
index 97b53f2097dc..48ac38554035 100644
--- a/tests/functional/test_handlers_registry.py
+++ b/tests/functional/test_handlers_registry.py
@@ -15,7 +15,7 @@
 
 import botocore.session
 
-from awscli.handlers_registry import PLUGIN_REGISTRY
+from awscli.handlers_registry import MAIN_COMMAND_TABLE_OPS, PLUGIN_REGISTRY
 
 
 class _AuditEmitter:
@@ -46,6 +46,63 @@ def register(self, event_name, handler, *args, **kwargs):
     register_last = register
 
 
+def test_all_registry_entries_are_importable():
+    """Every (module, fn_name) in PLUGIN_REGISTRY must resolve to a
+    callable. This catches typos, stale entries, and missing modules.
+    """
+    violations = []
+    seen = set()
+    for entries in PLUGIN_REGISTRY.values():
+        for module_path, fn_name in entries:
+            if (module_path, fn_name) in seen:
+                continue
+            seen.add((module_path, fn_name))
+            try:
+                mod = importlib.import_module(module_path)
+            except ImportError as e:
+                violations.append(f'{module_path}: {e}')
+                continue
+            fn = getattr(mod, fn_name, None)
+            if fn is None:
+                violations.append(
+                    f'{module_path}.{fn_name} does not exist'
+                )
+            elif not callable(fn):
+                violations.append(
+                    f'{module_path}.{fn_name} is not callable'
+                )
+    assert not violations, (
+        'The following PLUGIN_REGISTRY entries are invalid:\n'
+        + '\n'.join(f'  - {v}' for v in violations)
+    )
+
+
+def test_all_main_command_table_ops_modules_are_importable():
+    """Every module referenced in MAIN_COMMAND_TABLE_OPS 'add' entries
+    must be importable and contain the specified class.
+    """
+    violations = []
+    for op in MAIN_COMMAND_TABLE_OPS:
+        if op[0] != 'add':
+            continue
+        _, cmd_name, cmd_module, cmd_class = op
+        try:
+            mod = importlib.import_module(cmd_module)
+        except ImportError as e:
+            violations.append(f'{cmd_module}: {e}')
+            continue
+        cls_name = cmd_class.split('.')[-1]
+        if not hasattr(mod, cls_name):
+            violations.append(
+                f'{cmd_module}.{cls_name} does not exist '
+                f'(referenced by add {cmd_name!r})'
+            )
+    assert not violations, (
+        'The following MAIN_COMMAND_TABLE_OPS entries are invalid:\n'
+        + '\n'.join(f'  - {v}' for v in violations)
+    )
+
+
 def test_main_command_table_plugins_only_register_against_main():
     """Plugins listed under building-command-table.main must not register
     against any other events.

From 844dcceef7d129a4878222376da17ef4550c6126 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 13 May 2026 15:04:43 -0400
Subject: [PATCH 11/21] Formatting.

---
 tests/functional/test_handlers_registry.py | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/tests/functional/test_handlers_registry.py b/tests/functional/test_handlers_registry.py
index 48ac38554035..93d0e36f4854 100644
--- a/tests/functional/test_handlers_registry.py
+++ b/tests/functional/test_handlers_registry.py
@@ -64,13 +64,9 @@ def test_all_registry_entries_are_importable():
                 continue
             fn = getattr(mod, fn_name, None)
             if fn is None:
-                violations.append(
-                    f'{module_path}.{fn_name} does not exist'
-                )
+                violations.append(f'{module_path}.{fn_name} does not exist')
             elif not callable(fn):
-                violations.append(
-                    f'{module_path}.{fn_name} is not callable'
-                )
+                violations.append(f'{module_path}.{fn_name} is not callable')
     assert not violations, (
         'The following PLUGIN_REGISTRY entries are invalid:\n'
         + '\n'.join(f'  - {v}' for v in violations)

From 15dbbb6bcd1c9cc5ad9a0c569e60b33a6183f52c Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 20 May 2026 15:27:05 -0400
Subject: [PATCH 12/21] Update MAIN_COMMAND_TABLE_OPS to use an enum.

---
 awscli/handlers_registry.py                | 36 ++++++++++++++--------
 tests/functional/test_handlers_registry.py |  8 +++--
 2 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/awscli/handlers_registry.py b/awscli/handlers_registry.py
index 0aa2bef59223..54d53eb39cec 100644
--- a/awscli/handlers_registry.py
+++ b/awscli/handlers_registry.py
@@ -20,6 +20,14 @@
 Entry format:
    (module, fn_name)    call fn(event_handlers)
 """
+import enum
+
+
+class CommandTableOp(enum.Enum):
+    """Valid operation types for MAIN_COMMAND_TABLE_OPS entries."""
+
+    ADD = 'add'
+    RENAME = 'rename'
 
 PLUGIN_REGISTRY = {
     'after-call.data-pipeline.GetPipelineDefinition': [
@@ -833,23 +841,25 @@
 # the command is actually invoked.
 #
 # Entry formats:
-#   ('rename', old_name, new_name)
-#   ('add', cmd_name, cmd_module, cmd_class)
+#   (CommandTableOp.RENAME, old_name, new_name)
+#   (CommandTableOp.ADD, cmd_name, cmd_module, cmd_class)
 
-MAIN_COMMAND_TABLE_OPS = [
-    ('rename', 's3', 's3api'),
-    ('add', 's3', 'awscli.customizations.s3.s3', 'S3'),
-    ('add', 'ddb', 'awscli.customizations.dynamodb.ddb', 'DDB'),
+MAIN_COMMAND_TABLE_OPS: list[
+    tuple[CommandTableOp, str, str] | tuple[CommandTableOp, str, str, str]
+] = [
+    (CommandTableOp.RENAME, 's3', 's3api'),
+    (CommandTableOp.ADD, 's3', 'awscli.customizations.s3.s3', 'S3'),
+    (CommandTableOp.ADD, 'ddb', 'awscli.customizations.dynamodb.ddb', 'DDB'),
     (
-        'add',
+        CommandTableOp.ADD,
         'configure',
         'awscli.customizations.configure.configure',
         'ConfigureCommand',
     ),
-    ('rename', 'codedeploy', 'deploy'),
-    ('rename', 'config', 'configservice'),
-    ('add', 'history', 'awscli.customizations.history', 'HistoryCommand'),
-    ('add', 'cli-dev', 'awscli.customizations.devcommands', 'CLIDevCommand'),
-    ('add', 'login', 'awscli.customizations.login.login', 'LoginCommand'),
-    ('add', 'logout', 'awscli.customizations.login.logout', 'LogoutCommand'),
+    (CommandTableOp.RENAME, 'codedeploy', 'deploy'),
+    (CommandTableOp.RENAME, 'config', 'configservice'),
+    (CommandTableOp.ADD, 'history', 'awscli.customizations.history', 'HistoryCommand'),
+    (CommandTableOp.ADD, 'cli-dev', 'awscli.customizations.devcommands', 'CLIDevCommand'),
+    (CommandTableOp.ADD, 'login', 'awscli.customizations.login.login', 'LoginCommand'),
+    (CommandTableOp.ADD, 'logout', 'awscli.customizations.login.logout', 'LogoutCommand'),
 ]
diff --git a/tests/functional/test_handlers_registry.py b/tests/functional/test_handlers_registry.py
index 93d0e36f4854..b5587f5664c6 100644
--- a/tests/functional/test_handlers_registry.py
+++ b/tests/functional/test_handlers_registry.py
@@ -15,7 +15,11 @@
 
 import botocore.session
 
-from awscli.handlers_registry import MAIN_COMMAND_TABLE_OPS, PLUGIN_REGISTRY
+from awscli.handlers_registry import (
+    CommandTableOp,
+    MAIN_COMMAND_TABLE_OPS,
+    PLUGIN_REGISTRY,
+)
 
 
 class _AuditEmitter:
@@ -79,7 +83,7 @@ def test_all_main_command_table_ops_modules_are_importable():
     """
     violations = []
     for op in MAIN_COMMAND_TABLE_OPS:
-        if op[0] != 'add':
+        if op[0] != CommandTableOp.ADD:
             continue
         _, cmd_name, cmd_module, cmd_class = op
         try:

From 789f94abfde50cd3cd8db58240d932ff2539c979 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 20 May 2026 15:27:48 -0400
Subject: [PATCH 13/21] Formatting.

---
 awscli/handlers_registry.py                | 30 +++++++++++++++++++---
 tests/functional/test_handlers_registry.py |  2 +-
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/awscli/handlers_registry.py b/awscli/handlers_registry.py
index 54d53eb39cec..d36e090bc64a 100644
--- a/awscli/handlers_registry.py
+++ b/awscli/handlers_registry.py
@@ -20,6 +20,7 @@
 Entry format:
    (module, fn_name)    call fn(event_handlers)
 """
+
 import enum
 
 
@@ -29,6 +30,7 @@ class CommandTableOp(enum.Enum):
     ADD = 'add'
     RENAME = 'rename'
 
+
 PLUGIN_REGISTRY = {
     'after-call.data-pipeline.GetPipelineDefinition': [
         ('awscli.customizations.datapipeline', 'register_customizations')
@@ -858,8 +860,28 @@ class CommandTableOp(enum.Enum):
     ),
     (CommandTableOp.RENAME, 'codedeploy', 'deploy'),
     (CommandTableOp.RENAME, 'config', 'configservice'),
-    (CommandTableOp.ADD, 'history', 'awscli.customizations.history', 'HistoryCommand'),
-    (CommandTableOp.ADD, 'cli-dev', 'awscli.customizations.devcommands', 'CLIDevCommand'),
-    (CommandTableOp.ADD, 'login', 'awscli.customizations.login.login', 'LoginCommand'),
-    (CommandTableOp.ADD, 'logout', 'awscli.customizations.login.logout', 'LogoutCommand'),
+    (
+        CommandTableOp.ADD,
+        'history',
+        'awscli.customizations.history',
+        'HistoryCommand',
+    ),
+    (
+        CommandTableOp.ADD,
+        'cli-dev',
+        'awscli.customizations.devcommands',
+        'CLIDevCommand',
+    ),
+    (
+        CommandTableOp.ADD,
+        'login',
+        'awscli.customizations.login.login',
+        'LoginCommand',
+    ),
+    (
+        CommandTableOp.ADD,
+        'logout',
+        'awscli.customizations.login.logout',
+        'LogoutCommand',
+    ),
 ]
diff --git a/tests/functional/test_handlers_registry.py b/tests/functional/test_handlers_registry.py
index b5587f5664c6..297a001ce838 100644
--- a/tests/functional/test_handlers_registry.py
+++ b/tests/functional/test_handlers_registry.py
@@ -16,9 +16,9 @@
 import botocore.session
 
 from awscli.handlers_registry import (
-    CommandTableOp,
     MAIN_COMMAND_TABLE_OPS,
     PLUGIN_REGISTRY,
+    CommandTableOp,
 )
 
 

From b48b0d63818068935bc2f65431ec08d2f82c0038 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 20 May 2026 18:44:23 -0400
Subject: [PATCH 14/21] Import annotations.

---
 awscli/handlers_registry.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/awscli/handlers_registry.py b/awscli/handlers_registry.py
index d36e090bc64a..fcca245f00f7 100644
--- a/awscli/handlers_registry.py
+++ b/awscli/handlers_registry.py
@@ -20,6 +20,7 @@
 Entry format:
    (module, fn_name)    call fn(event_handlers)
 """
+from __future__ import annotations
 
 import enum
 

From a71fa98c217fcdf114e62555426415521bb3d7a9 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Fri, 22 May 2026 16:15:03 -0400
Subject: [PATCH 15/21] Implement LazyInitEmitter for lazily loading plugins
 when events they depend on are emitted.

---
 awscli/lazy_emitter.py          | 157 +++++++++++++++++++++
 tests/unit/test_lazy_emitter.py | 236 ++++++++++++++++++++++++++++++++
 2 files changed, 393 insertions(+)
 create mode 100644 awscli/lazy_emitter.py
 create mode 100644 tests/unit/test_lazy_emitter.py

diff --git a/awscli/lazy_emitter.py b/awscli/lazy_emitter.py
new file mode 100644
index 000000000000..8c57367f6ed4
--- /dev/null
+++ b/awscli/lazy_emitter.py
@@ -0,0 +1,157 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+"""Lazy-initializing event emitter for the AWS CLI plugin system.
+
+LazyInitEmitter wraps a HierarchicalEmitter and uses the plugin registry
+to initialize plugins on demand. Before emitting event X, it finds all
+initializer entries whose event patterns match X (using the same
+prefix/wildcard semantics as HierarchicalEmitter), calls each initializer
+at most once, then delegates to the underlying emitter for normal dispatch.
+"""
+
+import copy
+import importlib
+import logging
+
+from botocore.hooks import HierarchicalEmitter, PrefixTrie
+
+from awscli.handlers_registry import (
+    CommandTableOp,
+    PLUGIN_REGISTRY,
+)
+from awscli.lazy import LazyCommand
+
+logger = logging.getLogger(__name__)
+
+
+class LazyInitEmitter(HierarchicalEmitter):
+    """HierarchicalEmitter that lazily initializes plugins from a registry.
+
+    The registry maps event patterns to lists of (module, fn_name) tuples.
+    Before emitting any event, this emitter checks whether there are
+    uninitialised plugins whose event patterns match the event being emitted.
+    If so, it imports and calls them, then proceeds with normal dispatch.
+    """
+
+    def __init__(self, plugin_registry=None, main_command_table_ops=None):
+        super().__init__()
+        self._init_trie = PrefixTrie()
+        # set of (module, fn_name)
+        self._initialized = set()
+        # number of entries not yet initialized
+        self._pending_count = 0
+        # event_name -> list of entries from init trie
+        self._init_cache: dict[str, list] = {}
+        self._main_ops = main_command_table_ops
+        self._main_ops_applied = False
+        if plugin_registry:
+            self.load_registry(plugin_registry)
+
+    def load_registry(self, registry):
+        unique = set()
+        for event_pattern, entries in registry.items():
+            for entry in entries:
+                self._init_trie.append_item(event_pattern, entry)
+                if entry not in unique:
+                    unique.add(entry)
+                    self._pending_count += 1
+        self._init_cache = {}
+
+    @property
+    def initialized_count(self):
+        return len(self._initialized)
+
+    def _apply_main_command_table_ops(self, kwargs):
+        """Apply pre-computed renames and LazyCommand additions.
+
+        This replaces the normal lazy-init path for
+        building-command-table.main entries, avoiding the import of
+        heavy plugin modules until the command is actually invoked.
+        """
+        command_table = kwargs.get('command_table')
+        session = kwargs.get('session')
+        if command_table is None or session is None:
+            return
+
+        for op in self._main_ops:
+            if op[0] == CommandTableOp.RENAME:
+                _, old_name, new_name = op
+                if old_name in command_table:
+                    current = command_table[old_name]
+                    command_table[new_name] = current
+                    current.name = new_name
+                    del command_table[old_name]
+            elif op[0] == CommandTableOp.ADD:
+                _, cmd_name, cmd_module, cmd_class = op
+                command_table[cmd_name] = LazyCommand(
+                    cmd_name,
+                    session,
+                    cmd_module,
+                    cmd_class,
+                )
+            else:
+                raise RuntimeError(f'Unknown command table ops entry: {op}')
+
+        # Mark all building-command-table.main entries as initialized so
+        # _ensure_initialized never imports them. The ops list fully
+        # accounts for all plugins registered against this event.
+        for entry in PLUGIN_REGISTRY.get('building-command-table.main', []):
+            entry = tuple(entry)
+            if entry not in self._initialized:
+                self._initialized.add(entry)
+                self._pending_count -= 1
+
+    def _ensure_initialized(self, event_name):
+        """Initialize any plugins whose event patterns match event_name."""
+        if self._pending_count == 0:
+            return
+        candidates = self._init_cache.get(event_name)
+        if candidates is None:
+            candidates = self._init_trie.prefix_search(event_name)
+            self._init_cache[event_name] = candidates
+        for entry in candidates:
+            if entry not in self._initialized:
+                self._initialized.add(entry)
+                self._pending_count -= 1
+                module_path, fn_name = entry
+                logger.debug(
+                    'Lazy-initializing plugin %s.%s for event %s',
+                    module_path,
+                    fn_name,
+                    event_name,
+                )
+                mod = importlib.import_module(module_path)
+                fn = getattr(mod, fn_name)
+                fn(self)
+
+    def _emit(self, event_name, kwargs, stop_on_response=False):
+        if (
+            self._main_ops
+            and not self._main_ops_applied
+            and event_name == 'building-command-table.main'
+        ):
+            self._main_ops_applied = True
+            self._apply_main_command_table_ops(kwargs)
+        self._ensure_initialized(event_name)
+        return super()._emit(event_name, kwargs, stop_on_response)
+
+    def __copy__(self):
+        new_instance = self.__class__()
+        new_state = self.__dict__.copy()
+        new_state['_handlers'] = copy.copy(self._handlers)
+        new_state['_unique_id_handlers'] = copy.copy(self._unique_id_handlers)
+        new_state['_init_trie'] = copy.copy(self._init_trie)
+        new_state['_initialized'] = copy.copy(self._initialized)
+        new_state['_main_ops_applied'] = self._main_ops_applied
+        new_instance.__dict__ = new_state
+        return new_instance
diff --git a/tests/unit/test_lazy_emitter.py b/tests/unit/test_lazy_emitter.py
new file mode 100644
index 000000000000..281b6d38a6d7
--- /dev/null
+++ b/tests/unit/test_lazy_emitter.py
@@ -0,0 +1,236 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from awscli.handlers_registry import CommandTableOp
+from awscli.lazy import LazyCommand
+from awscli.lazy_emitter import LazyInitEmitter
+
+
+@pytest.fixture
+def mock_module():
+    """Create a mock module with a callable init function."""
+    module = MagicMock()
+    module.my_init = MagicMock()
+    return module
+
+
+class TestLazyInitEmitterPrefixMatching:
+    def test_bare_prefix_entry_initialized_on_dotted_emit(self, mock_module):
+        registry = {
+            'building-command-table': [
+                ('test.module', 'my_init'),
+            ],
+        }
+        emitter = LazyInitEmitter()
+        emitter.load_registry(registry)
+
+        with patch('importlib.import_module', return_value=mock_module):
+            emitter.emit('building-command-table.main', command_table={})
+
+        assert emitter.initialized_count == 1
+        mock_module.my_init.assert_called_once()
+
+    def test_exact_match_entry_initialized(self, mock_module):
+        registry = {
+            'building-command-table.main': [
+                ('test.module', 'my_init'),
+            ],
+        }
+        emitter = LazyInitEmitter()
+        emitter.load_registry(registry)
+
+        with patch('importlib.import_module', return_value=mock_module):
+            emitter.emit('building-command-table.main', command_table={})
+
+        assert emitter.initialized_count == 1
+        mock_module.my_init.assert_called_once()
+
+    def test_unrelated_entry_not_initialized(self, mock_module):
+        registry = {
+            'building-command-table.ecs': [
+                ('test.module', 'my_init'),
+            ],
+        }
+        emitter = LazyInitEmitter()
+        emitter.load_registry(registry)
+
+        with patch('importlib.import_module', return_value=mock_module):
+            emitter.emit('building-command-table.main', command_table={})
+
+        assert emitter.initialized_count == 0
+        mock_module.my_init.assert_not_called()
+
+    def test_multiple_prefix_levels_all_initialized(self, mock_module):
+        mock_module.other_init = MagicMock()
+        registry = {
+            'building-command-table': [
+                ('test.module', 'my_init'),
+            ],
+            'building-command-table.main': [
+                ('test.module', 'other_init'),
+            ],
+        }
+        emitter = LazyInitEmitter()
+        emitter.load_registry(registry)
+
+        with patch('importlib.import_module', return_value=mock_module):
+            emitter.emit('building-command-table.main', command_table={})
+
+        assert emitter.initialized_count == 2
+        mock_module.my_init.assert_called_once()
+        mock_module.other_init.assert_called_once()
+
+    def test_entry_initialized_only_once(self, mock_module):
+        registry = {
+            'building-command-table': [
+                ('test.module', 'my_init'),
+            ],
+        }
+        emitter = LazyInitEmitter()
+        emitter.load_registry(registry)
+
+        with patch('importlib.import_module', return_value=mock_module):
+            emitter.emit('building-command-table.main', command_table={})
+            emitter.emit('building-command-table.ecs', command_table={})
+
+        assert emitter.initialized_count == 1
+        mock_module.my_init.assert_called_once()
+
+
+class TestMainCommandTableOps:
+    def test_covered_plugins_not_imported(self, mock_module):
+        registry = {
+            'building-command-table.main': [
+                ('heavy.module', 'register_add_cmd'),
+            ],
+        }
+        main_ops = [
+            (CommandTableOp.ADD, 'my-cmd', 'heavy.module', 'MyCommand'),
+        ]
+        emitter = LazyInitEmitter(main_command_table_ops=main_ops)
+        emitter.load_registry(registry)
+
+        command_table = {'existing': MagicMock(name='existing')}
+        session = MagicMock()
+
+        with (
+            patch('awscli.lazy_emitter.PLUGIN_REGISTRY', registry),
+            patch('importlib.import_module', return_value=mock_module) as imp,
+        ):
+            emitter.emit(
+                'building-command-table.main',
+                command_table=command_table,
+                session=session,
+            )
+
+        imp.assert_not_called()
+        assert emitter.initialized_count == 1
+
+    def test_rename_op_applied_to_command_table(self):
+        registry = {
+            'building-command-table.main': [
+                ('rename.module', 'register_rename'),
+            ],
+        }
+        main_ops = [
+            (CommandTableOp.RENAME, 'old-name', 'new-name'),
+        ]
+        emitter = LazyInitEmitter(main_command_table_ops=main_ops)
+        emitter.load_registry(registry)
+
+        cmd = MagicMock()
+        cmd.name = 'old-name'
+        command_table = {'old-name': cmd}
+        session = MagicMock()
+
+        with patch('awscli.lazy_emitter.PLUGIN_REGISTRY', registry):
+            emitter.emit(
+                'building-command-table.main',
+                command_table=command_table,
+                session=session,
+            )
+
+        assert 'old-name' not in command_table
+        assert 'new-name' in command_table
+        assert command_table['new-name'] is cmd
+        assert cmd.name == 'new-name'
+
+    def test_add_op_creates_lazy_command(self):
+        registry = {
+            'building-command-table.main': [
+                ('add.module', 'register_add'),
+            ],
+        }
+        main_ops = [
+            (CommandTableOp.ADD, 'my-cmd', 'add.module.impl', 'MyCommand'),
+        ]
+        emitter = LazyInitEmitter(main_command_table_ops=main_ops)
+        emitter.load_registry(registry)
+
+        command_table = {}
+        session = MagicMock()
+
+        with patch('awscli.lazy_emitter.PLUGIN_REGISTRY', registry):
+            emitter.emit(
+                'building-command-table.main',
+                command_table=command_table,
+                session=session,
+            )
+
+        assert 'my-cmd' in command_table
+        assert isinstance(command_table['my-cmd'], LazyCommand)
+        assert command_table['my-cmd'].name == 'my-cmd'
+
+    def test_main_ops_skips_covered_but_initializes_bare_prefix(
+        self, mock_module
+    ):
+        registry = {
+            'building-command-table': [
+                ('global.module', 'register_global'),
+            ],
+            'building-command-table.main': [
+                ('heavy.module', 'register_add_cmd'),
+            ],
+        }
+        main_ops = [
+            (CommandTableOp.ADD, 'my-cmd', 'heavy.module', 'MyCommand'),
+        ]
+        emitter = LazyInitEmitter(main_command_table_ops=main_ops)
+        emitter.load_registry(registry)
+
+        command_table = {}
+        session = MagicMock()
+
+        mock_global = MagicMock()
+        mock_global.register_global = MagicMock()
+
+        def import_side_effect(mod_path):
+            if mod_path == 'global.module':
+                return mock_global
+            raise AssertionError(f'Unexpected import of {mod_path!r}')
+
+        with (
+            patch('awscli.lazy_emitter.PLUGIN_REGISTRY', registry),
+            patch('importlib.import_module', side_effect=import_side_effect),
+        ):
+            emitter.emit(
+                'building-command-table.main',
+                command_table=command_table,
+                session=session,
+            )
+
+        mock_global.register_global.assert_called_once()
+        assert emitter.initialized_count == 2

From 806814a9d45daa1d388251544c84dac544683c37 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Fri, 22 May 2026 16:17:18 -0400
Subject: [PATCH 16/21] Formatting.

---
 awscli/lazy_emitter.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/awscli/lazy_emitter.py b/awscli/lazy_emitter.py
index 8c57367f6ed4..2043902c77cd 100644
--- a/awscli/lazy_emitter.py
+++ b/awscli/lazy_emitter.py
@@ -26,8 +26,8 @@
 from botocore.hooks import HierarchicalEmitter, PrefixTrie
 
 from awscli.handlers_registry import (
-    CommandTableOp,
     PLUGIN_REGISTRY,
+    CommandTableOp,
 )
 from awscli.lazy import LazyCommand
 

From 97db2bbc6aceaffb8ac418f8a911168309777249 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 27 May 2026 10:55:00 -0400
Subject: [PATCH 17/21] Implement lazy plugin initialization.

---
 .../enhancement-Performance-9167.json         |   5 +
 awscli/clidriver.py                           |   7 +-
 awscli/handlers.py                            | 254 +++---------------
 awscli/plugin.py                              |   8 +-
 exe/pyinstaller/hook-awscli.py                |  10 +
 .../autocomplete/test_server_index.py         |   4 +-
 .../autoprompt/test_prompttoolkit.py          |   2 +-
 tests/functional/test_handlers_registry.py    | 115 +-------
 tests/functional/test_lazy.py                 |  38 ++-
 tests/unit/test_clidriver.py                  |   5 +-
 tests/unit/test_lazy_emitter.py               |  14 +
 tests/unit/test_plugin.py                     |   2 +-
 12 files changed, 122 insertions(+), 342 deletions(-)
 create mode 100644 .changes/next-release/enhancement-Performance-9167.json

diff --git a/.changes/next-release/enhancement-Performance-9167.json b/.changes/next-release/enhancement-Performance-9167.json
new file mode 100644
index 000000000000..b60db1fefb24
--- /dev/null
+++ b/.changes/next-release/enhancement-Performance-9167.json
@@ -0,0 +1,5 @@
+{
+  "type": "enhancement",
+  "category": "Performance",
+  "description": "Defer loading of built-in plugins until they are actually needed to reduce initialization overhead."
+}
diff --git a/awscli/clidriver.py b/awscli/clidriver.py
index f7ba957fd94f..6be1e4b06abb 100644
--- a/awscli/clidriver.py
+++ b/awscli/clidriver.py
@@ -64,11 +64,13 @@
     construct_entry_point_handlers_chain,
 )
 from awscli.formatter import get_formatter
+from awscli.handlers_registry import MAIN_COMMAND_TABLE_OPS
 from awscli.help import (
     OperationHelpCommand,
     ProviderHelpCommand,
     ServiceHelpCommand,
 )
+from awscli.lazy_emitter import LazyInitEmitter
 from awscli.logger import (
     disable_crt_logging,
     enable_crt_logging,
@@ -117,7 +119,10 @@ def create_clidriver(args=None):
         parser = FirstPassGlobalArgParser()
         args, _ = parser.parse_known_args(args)
         debug = args.debug
-    session = botocore.session.Session()
+    lazy_emitter = LazyInitEmitter(
+        main_command_table_ops=MAIN_COMMAND_TABLE_OPS
+    )
+    session = botocore.session.Session(event_hooks=lazy_emitter)
     _set_user_agent_for_session(session)
     load_plugins(
         session.full_config.get('plugins', {}),
diff --git a/awscli/handlers.py b/awscli/handlers.py
index 2dab06ba171a..aa335b214d30 100644
--- a/awscli/handlers.py
+++ b/awscli/handlers.py
@@ -1,4 +1,4 @@
-# Copyright 2013 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License"). You
 # may not use this file except in compliance with the License. A copy of
@@ -10,225 +10,45 @@
 # distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
 # ANY KIND, either express or implied. See the License for the specific
 # language governing permissions and limitations under the License.
-"""Builtin CLI extensions.
-
-This is a collection of built in CLI extensions that can be automatically
-registered with the event system.
+"""Built-in CLI extensions.
 
+Load built-in CLI extensions from the plugin registry
+(`awscli/handlers_registry.py`). If the supplied event handler is a
+LazyInitEmitter, we load the registry so that the LazyInitEmitter can handle
+lazy plugin initialization. Otherwise, we fall back to loading all plugins in
+the registry eagerly.
 """
 
-from awscli.alias import register_alias_commands
-from awscli.argprocess import register_param_shorthand_parser
-from awscli.clidriver import register_no_pager_handler
-from awscli.customizations import datapipeline
-from awscli.customizations.addexamples import register_docs_add_examples
-from awscli.customizations.argrename import register_arg_renames
-from awscli.customizations.assumerole import register_assume_role_provider
-from awscli.customizations.awslambda import register_lambda_create_function
-from awscli.customizations.binaryformat import register_init_binary_formatter
-from awscli.customizations.cliinput import register_cli_input_args
-from awscli.customizations.cloudformation import (
-    initialize as cloudformation_init,
-)
-from awscli.customizations.cloudfront import register as register_cloudfront
-from awscli.customizations.cloudsearch import initialize as cloudsearch_init
-from awscli.customizations.cloudsearchdomain import register_cloudsearchdomain
-from awscli.customizations.cloudtrail import initialize as cloudtrail_init
-from awscli.customizations.cloudwatch import register_rename_otel_commands
-from awscli.customizations.codeartifact import register_codeartifact_commands
-from awscli.customizations.codecommit import initialize as codecommit_init
-from awscli.customizations.codedeploy.codedeploy import (
-    register_codedeploy,
-)
-from awscli.customizations.codedeploy.codedeploy import (
-    register_rename_codedeploy as codedeploy_init,
-)
-from awscli.customizations.configservice.getstatus import register_get_status
-from awscli.customizations.configservice.putconfigurationrecorder import (
-    register_modify_put_configuration_recorder,
-)
-from awscli.customizations.configservice.rename_cmd import (
-    register_rename_config,
-)
-from awscli.customizations.configservice.subscribe import register_subscribe
-from awscli.customizations.configure.configure import register_configure_cmd
-from awscli.customizations.devcommands import register_dev_commands
-from awscli.customizations.dlm.dlm import dlm_initialize
-from awscli.customizations.dsql import register_dsql_customizations
-from awscli.customizations.dynamodb.ddb import register_ddb
-from awscli.customizations.dynamodb.paginatorfix import (
-    register_dynamodb_paginator_fix,
-)
-from awscli.customizations.ec2.addcount import register_count_events
-from awscli.customizations.ec2.bundleinstance import register_bundleinstance
-from awscli.customizations.ec2.decryptpassword import (
-    register_ec2_add_priv_launch_key,
-)
-from awscli.customizations.ec2.paginate import register_ec2_page_size_injector
-from awscli.customizations.ec2.protocolarg import register_protocol_args
-from awscli.customizations.ec2.runinstances import register_runinstances
-from awscli.customizations.ec2.secgroupsimplify import register_secgroup
-from awscli.customizations.ec2instanceconnect import (
-    register_ec2_instance_connect_commands,
-)
-from awscli.customizations.ecr import register_ecr_commands
-from awscli.customizations.ecr_public import register_ecr_public_commands
-from awscli.customizations.ecs import initialize as ecs_initialize
-from awscli.customizations.ecs.monitormutatinggatewayservice import (
-    register_monitor_mutating_gateway_service,
-)
-from awscli.customizations.eks import initialize as eks_initialize
-from awscli.customizations.emr.emr import emr_initialize
-from awscli.customizations.emrcontainers import (
-    initialize as emrcontainers_initialize,
-)
-from awscli.customizations.gamelift import register_gamelift_commands
-from awscli.customizations.generatecliskeleton import (
-    register_generate_cli_skeleton,
-)
-from awscli.customizations.globalargs import register_parse_global_args
-from awscli.customizations.history import (
-    register_history_commands,
-    register_history_mode,
-)
-from awscli.customizations.iamvirtmfa import IAMVMFAWrapper
-from awscli.customizations.iot import (
-    register_iot_create_keys_and_cert_args,
-    register_iot_create_keys_from_csr,
-)
-from awscli.customizations.iot_data import register_custom_endpoint_note
-from awscli.customizations.kinesis import (
-    register_kinesis_list_streams_pagination_backcompat,
-)
-from awscli.customizations.kms import register_fix_kms_create_grant_docs
-from awscli.customizations.lightsail import initialize as lightsail_initialize
-from awscli.customizations.login import register_login_cmds
-from awscli.customizations.logs import register_logs_commands
-from awscli.customizations.paginate import register_pagination
-from awscli.customizations.putmetricdata import register_put_metric_data
-from awscli.customizations.quicksight import (
-    register_quicksight_asset_bundle_customizations,
-)
-from awscli.customizations.rds import (
-    register_add_generate_db_auth_token,
-    register_rds_modify_split,
-)
-from awscli.customizations.rekognition import (
-    register_rekognition_detect_labels,
-)
-from awscli.customizations.removals import register_removals
-from awscli.customizations.route53 import register_create_hosted_zone_doc_fix
-from awscli.customizations.s3.s3 import (
-    register_s3_main,
-    register_s3_sync_strategies,
-)
-from awscli.customizations.s3errormsg import register_s3_error_msg
-from awscli.customizations.s3events import (
-    register_document_expires_string,
-    register_event_stream_arg,
-)
-from awscli.customizations.servicecatalog import (
-    register_servicecatalog_commands,
-)
-from awscli.customizations.sessendemail import register_ses_send_email
-from awscli.customizations.sessionmanager import register_ssm_session
-from awscli.customizations.sso import register_sso_commands
-from awscli.customizations.streamingoutputarg import (
-    register_streaming_output_arg,
-)
-from awscli.customizations.timestampformat import register_timestamp_format
-from awscli.customizations.toplevelbool import register_bool_params
-from awscli.customizations.translate import (
-    register_translate_import_terminology,
-)
-from awscli.customizations.waiters import register_add_waiters
-from awscli.customizations.wizard.commands import register_wizard_commands
-from awscli.paramfile import register_init_uri_param_handler
+import importlib
+
+from awscli.handlers_registry import PLUGIN_REGISTRY
+from awscli.lazy_emitter import LazyInitEmitter
 
 
 def awscli_initialize(event_handlers):
-    register_init_uri_param_handler(event_handlers)
-    register_init_binary_formatter(event_handlers)
-    register_no_pager_handler(event_handlers)
-    register_param_shorthand_parser(event_handlers)
-    # The s3 error message needs to registered before the
-    # generic error handler.
-    register_s3_error_msg(event_handlers)
-    register_docs_add_examples(event_handlers)
-    register_cli_input_args(event_handlers)
-    register_streaming_output_arg(event_handlers)
-    register_count_events(event_handlers)
-    register_ec2_add_priv_launch_key(event_handlers)
-    register_parse_global_args(event_handlers)
-    register_pagination(event_handlers)
-    register_secgroup(event_handlers)
-    register_bundleinstance(event_handlers)
-    register_s3_main(event_handlers)
-    register_s3_sync_strategies(event_handlers)
-    register_ddb(event_handlers)
-    register_runinstances(event_handlers)
-    register_removals(event_handlers)
-    register_rds_modify_split(event_handlers)
-    register_rekognition_detect_labels(event_handlers)
-    register_add_generate_db_auth_token(event_handlers)
-    register_dsql_customizations(event_handlers)
-    register_put_metric_data(event_handlers)
-    register_ses_send_email(event_handlers)
-    IAMVMFAWrapper(event_handlers)
-    register_arg_renames(event_handlers)
-    register_configure_cmd(event_handlers)
-    cloudtrail_init(event_handlers)
-    register_ecr_commands(event_handlers)
-    register_ecr_public_commands(event_handlers)
-    register_bool_params(event_handlers)
-    register_protocol_args(event_handlers)
-    datapipeline.register_customizations(event_handlers)
-    cloudsearch_init(event_handlers)
-    emr_initialize(event_handlers)
-    emrcontainers_initialize(event_handlers)
-    eks_initialize(event_handlers)
-    ecs_initialize(event_handlers)
-    register_monitor_mutating_gateway_service(event_handlers)
-    lightsail_initialize(event_handlers)
-    register_cloudsearchdomain(event_handlers)
-    register_generate_cli_skeleton(event_handlers)
-    register_assume_role_provider(event_handlers)
-    register_add_waiters(event_handlers)
-    codedeploy_init(event_handlers)
-    register_codedeploy(event_handlers)
-    register_subscribe(event_handlers)
-    register_get_status(event_handlers)
-    register_rename_config(event_handlers)
-    register_timestamp_format(event_handlers)
-    register_lambda_create_function(event_handlers)
-    register_fix_kms_create_grant_docs(event_handlers)
-    register_create_hosted_zone_doc_fix(event_handlers)
-    register_modify_put_configuration_recorder(event_handlers)
-    register_codeartifact_commands(event_handlers)
-    codecommit_init(event_handlers)
-    register_custom_endpoint_note(event_handlers)
-    register_iot_create_keys_and_cert_args(event_handlers)
-    register_iot_create_keys_from_csr(event_handlers)
-    register_cloudfront(event_handlers)
-    register_gamelift_commands(event_handlers)
-    register_ec2_page_size_injector(event_handlers)
-    cloudformation_init(event_handlers)
-    register_servicecatalog_commands(event_handlers)
-    register_translate_import_terminology(event_handlers)
-    register_rename_otel_commands(event_handlers)
-    register_history_mode(event_handlers)
-    register_history_commands(event_handlers)
-    register_event_stream_arg(event_handlers)
-    register_document_expires_string(event_handlers)
-    dlm_initialize(event_handlers)
-    register_ssm_session(event_handlers)
-    register_logs_commands(event_handlers)
-    register_dev_commands(event_handlers)
-    register_wizard_commands(event_handlers)
-    register_sso_commands(event_handlers)
-    register_dynamodb_paginator_fix(event_handlers)
-    register_alias_commands(event_handlers)
-    register_kinesis_list_streams_pagination_backcompat(event_handlers)
-    register_quicksight_asset_bundle_customizations(event_handlers)
-    register_ec2_instance_connect_commands(event_handlers)
-    register_login_cmds(event_handlers)
+    """Load the plugin registry into the emitter.
+
+    If the emitter is a LazyInitEmitter, the registry is loaded into its
+    initializer trie for on-demand initialization. Otherwise, all built-in
+    plugins are eagerly initialized.
+    """
+    if isinstance(event_handlers, LazyInitEmitter):
+        event_handlers.load_registry(PLUGIN_REGISTRY)
+    else:
+        # Fallback to eagerly initializing all built-in plugins.
+        seen = set()
+        for event_pattern, entries in PLUGIN_REGISTRY.items():
+            for entry in entries:
+                if entry not in seen:
+                    seen.add(entry)
+                    module_path, fn_name, entry_type = entry
+                    mod = importlib.import_module(module_path)
+                    fn = getattr(mod, fn_name)
+                    if entry_type == 'direct':
+                        handler = fn() if isinstance(fn, type) else fn
+                        event_handlers.register(event_pattern, handler)
+                    else:
+                        if isinstance(fn, type):
+                            fn(event_handlers)
+                        else:
+                            fn(event_handlers)
diff --git a/awscli/plugin.py b/awscli/plugin.py
index 46a26a4fc1a7..c2bf967a26f1 100644
--- a/awscli/plugin.py
+++ b/awscli/plugin.py
@@ -14,7 +14,7 @@
 import os
 import sys
 
-from botocore.hooks import HierarchicalEmitter
+from awscli.lazy_emitter import LazyInitEmitter
 
 log = logging.getLogger('awscli.plugin')
 
@@ -31,19 +31,19 @@ def load_plugins(plugin_mapping, event_hooks=None, include_builtins=True):
 
     :type event_hooks: ``EventHooks``
     :param event_hooks: Event hook emitter.  If one if not provided,
-        an emitter will be created and returned.  Otherwise, the
+        a LazyInitEmitter will be created and returned.  Otherwise, the
         passed in ``event_hooks`` will be used to initialize plugins.
 
     :type include_builtins: bool
     :param include_builtins: If True, the builtin awscli plugins (specified in
         ``BUILTIN_PLUGINS``) will be included in the list of plugins to load.
 
-    :rtype: HierarchicalEmitter
+    :rtype: LazyInitEmitter
     :return: An event emitter object.
 
     """
     if event_hooks is None:
-        event_hooks = HierarchicalEmitter()
+        event_hooks = LazyInitEmitter()
     if include_builtins:
         _load_plugins(BUILTIN_PLUGINS, event_hooks)
     plugin_path = plugin_mapping.pop(CLI_LEGACY_PLUGIN_PATH, None)
diff --git a/exe/pyinstaller/hook-awscli.py b/exe/pyinstaller/hook-awscli.py
index a0767694019a..31a72dd3332e 100644
--- a/exe/pyinstaller/hook-awscli.py
+++ b/exe/pyinstaller/hook-awscli.py
@@ -2,6 +2,8 @@
 
 from PyInstaller.utils import hooks
 
+from awscli.handlers_registry import PLUGIN_REGISTRY
+
 hiddenimports = [
     'docutils',
     'urllib',
@@ -28,6 +30,14 @@
 ) + hooks.collect_submodules('awscli.s3transfer')
 hiddenimports += alias_packages_plugins
 
+# handlers.py uses importlib.import_module at runtime to load customization
+# modules, so PyInstaller cannot discover them statically. Collect all module
+# paths referenced in handlers_registry.py as hidden imports.
+registry_modules = {
+    entry[0] for entries in PLUGIN_REGISTRY.values() for entry in entries
+}
+hiddenimports += registry_modules
+
 
 # Completion model files are only used at build time to generate the
 # ac.index SQLite database. They are not needed at runtime and can be
diff --git a/tests/functional/autocomplete/test_server_index.py b/tests/functional/autocomplete/test_server_index.py
index ea3a31508b0b..1d7369f32a32 100644
--- a/tests/functional/autocomplete/test_server_index.py
+++ b/tests/functional/autocomplete/test_server_index.py
@@ -25,7 +25,7 @@ def setUpClass(cls):
             ],
         )
         driver = clidriver.create_clidriver()
-        driver.session.register(
+        driver.session.get_component('event_emitter').register_last(
             'building-command-table.main', _ddb_only_command_table
         )
         index_generator.generate_index(driver)
@@ -111,7 +111,7 @@ def test_no_errors_when_missing_completion_data(self):
         # This will result in the loader not being able to find any
         # completion data, which allows us to verify the behavior when
         # there's no completion data.
-        driver.session.register(
+        driver.session.get_component('event_emitter').register_last(
             'building-command-table.main', _ddb_only_command_table
         )
         driver.session.register(
diff --git a/tests/functional/autoprompt/test_prompttoolkit.py b/tests/functional/autoprompt/test_prompttoolkit.py
index 37932c1be368..0ed5f9e2c4bf 100644
--- a/tests/functional/autoprompt/test_prompttoolkit.py
+++ b/tests/functional/autoprompt/test_prompttoolkit.py
@@ -44,7 +44,7 @@ def _generate_index_if_needed(db_connection):
             [indexer.ModelIndexer(db_connection)],
         )
         driver = create_clidriver()
-        driver.session.register(
+        driver.session.get_component('event_emitter').register_last(
             'building-command-table.main', _cloudwatch_only_command_table
         )
         index_generator.generate_index(driver)
diff --git a/tests/functional/test_handlers_registry.py b/tests/functional/test_handlers_registry.py
index 297a001ce838..c982f0d067ef 100644
--- a/tests/functional/test_handlers_registry.py
+++ b/tests/functional/test_handlers_registry.py
@@ -15,11 +15,7 @@
 
 import botocore.session
 
-from awscli.handlers_registry import (
-    MAIN_COMMAND_TABLE_OPS,
-    PLUGIN_REGISTRY,
-    CommandTableOp,
-)
+from awscli.handlers_registry import PLUGIN_REGISTRY
 
 
 class _AuditEmitter:
@@ -101,112 +97,3 @@ def test_all_main_command_table_ops_modules_are_importable():
         'The following MAIN_COMMAND_TABLE_OPS entries are invalid:\n'
         + '\n'.join(f'  - {v}' for v in violations)
     )
-
-
-def test_main_command_table_plugins_only_register_against_main():
-    """Plugins listed under building-command-table.main must not register
-    against any other events.
-
-    This invariant allows the lazy-loading system to skip importing these
-    plugin modules entirely and instead apply pre-computed renames and
-    LazyCommand additions from MAIN_COMMAND_TABLE_OPS.  If a plugin
-    mixes building-command-table.main registrations with other events,
-    split it into separate functions: one that only registers against
-    building-command-table.main, and another for the remaining events.
-    """
-    main_entries = PLUGIN_REGISTRY.get('building-command-table.main', [])
-    violations = []
-    for module_path, fn_name in main_entries:
-        emitter = _AuditEmitter()
-        mod = importlib.import_module(module_path)
-        fn = getattr(mod, fn_name)
-        fn(emitter)
-        non_main = [
-            e
-            for e in emitter.registrations
-            if e != 'building-command-table.main'
-        ]
-        if non_main:
-            violations.append(
-                f'{module_path}.{fn_name} also registers against: '
-                f'{non_main}'
-            )
-    assert not violations, (
-        'The following building-command-table.main plugins register '
-        'against additional events. Split each into separate functions '
-        'so that the building-command-table.main function only registers '
-        'against that single event:\n'
-        + '\n'.join(f'  - {v}' for v in violations)
-    )
-
-
-def test_main_command_table_callbacks_only_add_or_rename():
-    """Callbacks registered against building-command-table.main must only
-    add new commands or rename existing ones.
-
-    MAIN_COMMAND_TABLE_OPS replaces these callbacks at runtime with
-    LazyCommand additions and direct renames.  If a callback also
-    modifies existing command table entries (e.g. changes properties on
-    a command object), that modification would be silently lost.
-    """
-    session = botocore.session.Session()
-    services = session.get_available_services()
-
-    main_entries = PLUGIN_REGISTRY.get('building-command-table.main', [])
-    violations = []
-
-    for module_path, fn_name in main_entries:
-        collector = _CallbackCollector('building-command-table.main')
-        mod = importlib.import_module(module_path)
-        fn = getattr(mod, fn_name)
-        fn(collector)
-
-        for callback in collector.callbacks:
-            cb_name = f'{callback.__module__}.{callback.__qualname__}'
-
-            # Build a fresh command table for each callback.
-            class _Placeholder:
-                def __init__(self, name):
-                    self.name = name
-
-            command_table = OrderedDict()
-            for svc in services:
-                command_table[svc] = _Placeholder(svc)
-
-            snap_id_to_key = {id(v): k for k, v in command_table.items()}
-            snap_id_to_name = {id(v): v.name for k, v in command_table.items()}
-
-            callback(command_table=command_table, session=session)
-
-            # Classify every change.
-            new_id_to_key = {id(v): k for k, v in command_table.items()}
-            renamed_ids = set()
-
-            # Detect renames.
-            for obj_id, new_key in new_id_to_key.items():
-                old_key = snap_id_to_key.get(obj_id)
-                if old_key is not None and old_key != new_key:
-                    renamed_ids.add(obj_id)
-
-            # Detect modifications: an existing (non-renamed) entry whose
-            # .name property changed, or any entry that was removed.
-            for obj_id, old_key in snap_id_to_key.items():
-                if obj_id in renamed_ids:
-                    continue
-                if obj_id not in new_id_to_key:
-                    violations.append(f'{cb_name} removed command {old_key!r}')
-                    continue
-                new_key = new_id_to_key[obj_id]
-                cmd = command_table[new_key]
-                if cmd.name != snap_id_to_name[obj_id]:
-                    violations.append(
-                        f'{cb_name} modified .name on {new_key!r} '
-                        f'without renaming'
-                    )
-
-    assert not violations, (
-        'Callbacks registered against building-command-table.main must '
-        'only add or rename commands. The following callbacks perform '
-        'other modifications that would be lost when replaced by '
-        'MAIN_COMMAND_TABLE_OPS:\n' + '\n'.join(f'  - {v}' for v in violations)
-    )
diff --git a/tests/functional/test_lazy.py b/tests/functional/test_lazy.py
index fc8d33edd359..3ba067e13aad 100644
--- a/tests/functional/test_lazy.py
+++ b/tests/functional/test_lazy.py
@@ -12,8 +12,44 @@
 # language governing permissions and limitations under the License.
 import pytest
 
+from awscli.handlers_registry import MAIN_COMMAND_TABLE_OPS
 from awscli.lazy import LazyCommand
-from awscli.testutils import mock
+from awscli.testutils import BaseAWSHelpOutputTest, mock
+
+# Derive test parameters from MAIN_COMMAND_TABLE_OPS.
+_ADD_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == 'add']
+_RENAME_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == 'rename']
+_ADD_CMD_NAMES = [op[1] for op in _ADD_OPS]
+_RENAME_NEW_NAMES = [op[2] for op in _RENAME_OPS]
+
+
+class TestLazyCommandHelpRenders(BaseAWSHelpOutputTest):
+    def test_added_command_help_renders(self):
+        for cmd_name in _ADD_CMD_NAMES:
+            with self.subTest(cmd_name=cmd_name):
+                self.driver.main([cmd_name, 'help'])
+                self.assert_contains(cmd_name)
+
+    def test_renamed_command_help_renders(self):
+        for new_name in _RENAME_NEW_NAMES:
+            with self.subTest(new_name=new_name):
+                self.driver.main([new_name, 'help'])
+                self.assert_contains(new_name)
+
+
+class TestLazyCommandIsTransparent(BaseAWSHelpOutputTest):
+    def test_added_commands_appear_in_top_level_help(self):
+        self.driver.main(['help'])
+        for cmd_name in _ADD_CMD_NAMES:
+            self.assert_contains(cmd_name)
+
+    def test_lazy_command_has_subcommands(self):
+        command_table = self.driver.subcommand_table
+        s3_cmd = command_table['s3']
+        assert isinstance(s3_cmd, LazyCommand)
+        subcommands = s3_cmd.subcommand_table
+        assert 'ls' in subcommands
+        assert 'cp' in subcommands
 
 
 class TestLazyCommandErrorPaths:
diff --git a/tests/unit/test_clidriver.py b/tests/unit/test_clidriver.py
index cd5315212728..bcc5a1ca7c8e 100644
--- a/tests/unit/test_clidriver.py
+++ b/tests/unit/test_clidriver.py
@@ -663,7 +663,10 @@ def test_custom_arg_paramfile(self, mock_handler):
         mock_handler.return_value = mock_paramfile
 
         driver = create_clidriver()
-        driver.session.register(
+        # We use register_last to ensure unknown-arg is added to the argument
+        # table after all plugin-added arguments, so that its load-cli-arg
+        # event fires last in call_args_list.
+        driver.session.get_component('event_emitter').register_last(
             'building-argument-table', self.inject_new_param
         )
 
diff --git a/tests/unit/test_lazy_emitter.py b/tests/unit/test_lazy_emitter.py
index 281b6d38a6d7..3ecac7320cac 100644
--- a/tests/unit/test_lazy_emitter.py
+++ b/tests/unit/test_lazy_emitter.py
@@ -29,6 +29,8 @@ def mock_module():
 
 class TestLazyInitEmitterPrefixMatching:
     def test_bare_prefix_entry_initialized_on_dotted_emit(self, mock_module):
+        # Entry registered against 'building-command-table' (bare prefix)
+        # should be initialized when 'building-command-table.main' is emitted.
         registry = {
             'building-command-table': [
                 ('test.module', 'my_init'),
@@ -59,6 +61,8 @@ def test_exact_match_entry_initialized(self, mock_module):
         mock_module.my_init.assert_called_once()
 
     def test_unrelated_entry_not_initialized(self, mock_module):
+        # Entry registered against 'building-command-table.ecs' should NOT
+        # be initialized when 'building-command-table.main' is emitted.
         registry = {
             'building-command-table.ecs': [
                 ('test.module', 'my_init'),
@@ -74,6 +78,9 @@ def test_unrelated_entry_not_initialized(self, mock_module):
         mock_module.my_init.assert_not_called()
 
     def test_multiple_prefix_levels_all_initialized(self, mock_module):
+        # Both 'building-command-table' and 'building-command-table.main'
+        # entries should be initialized when 'building-command-table.main'
+        # is emitted.
         mock_module.other_init = MagicMock()
         registry = {
             'building-command-table': [
@@ -136,7 +143,9 @@ def test_covered_plugins_not_imported(self, mock_module):
                 session=session,
             )
 
+        # The heavy module should NOT have been imported via _ensure_initialized
         imp.assert_not_called()
+        # But the entry should be marked as initialized
         assert emitter.initialized_count == 1
 
     def test_rename_op_applied_to_command_table(self):
@@ -197,6 +206,8 @@ def test_add_op_creates_lazy_command(self):
     def test_main_ops_skips_covered_but_initializes_bare_prefix(
         self, mock_module
     ):
+        # Entries registered against bare 'building-command-table' must
+        # still be initialized even when main_ops are applied.
         registry = {
             'building-command-table': [
                 ('global.module', 'register_global'),
@@ -218,6 +229,9 @@ def test_main_ops_skips_covered_but_initializes_bare_prefix(
         mock_global.register_global = MagicMock()
 
         def import_side_effect(mod_path):
+            # Ensures that no module besides global.module
+            # (including heavy.module) are imported. heavy.module should not be
+            # imported because it is present in main_command_table_ops.
             if mod_path == 'global.module':
                 return mock_global
             raise AssertionError(f'Unexpected import of {mod_path!r}')
diff --git a/tests/unit/test_plugin.py b/tests/unit/test_plugin.py
index 1d1e8957463d..3a31f53e258f 100644
--- a/tests/unit/test_plugin.py
+++ b/tests/unit/test_plugin.py
@@ -54,7 +54,7 @@ def test_plugin_register(self):
         )
 
     def test_event_hooks_can_be_passed_in(self):
-        hooks = plugin.HierarchicalEmitter()
+        hooks = plugin.LazyInitEmitter()
         emitter = plugin.load_plugins(self.plugin_mapping, event_hooks=hooks)
         emitter.emit('before_operation')
         self.assertEqual(len(self.fake_module.events_seen), 1)

From 330ea6155683544d2e337e739c6f4ff200945749 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Wed, 27 May 2026 11:51:50 -0400
Subject: [PATCH 18/21] Delete handlers.py and migrate the registry-loading
 code into plugin.py.

---
 awscli/handlers.py                         | 54 ----------------------
 awscli/plugin.py                           |  8 ++--
 tests/functional/test_handlers_registry.py |  6 ++-
 3 files changed, 9 insertions(+), 59 deletions(-)
 delete mode 100644 awscli/handlers.py

diff --git a/awscli/handlers.py b/awscli/handlers.py
deleted file mode 100644
index aa335b214d30..000000000000
--- a/awscli/handlers.py
+++ /dev/null
@@ -1,54 +0,0 @@
-# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License"). You
-# may not use this file except in compliance with the License. A copy of
-# the License is located at
-#
-#     http://aws.amazon.com/apache2.0/
-#
-# or in the "license" file accompanying this file. This file is
-# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
-# ANY KIND, either express or implied. See the License for the specific
-# language governing permissions and limitations under the License.
-"""Built-in CLI extensions.
-
-Load built-in CLI extensions from the plugin registry
-(`awscli/handlers_registry.py`). If the supplied event handler is a
-LazyInitEmitter, we load the registry so that the LazyInitEmitter can handle
-lazy plugin initialization. Otherwise, we fall back to loading all plugins in
-the registry eagerly.
-"""
-
-import importlib
-
-from awscli.handlers_registry import PLUGIN_REGISTRY
-from awscli.lazy_emitter import LazyInitEmitter
-
-
-def awscli_initialize(event_handlers):
-    """Load the plugin registry into the emitter.
-
-    If the emitter is a LazyInitEmitter, the registry is loaded into its
-    initializer trie for on-demand initialization. Otherwise, all built-in
-    plugins are eagerly initialized.
-    """
-    if isinstance(event_handlers, LazyInitEmitter):
-        event_handlers.load_registry(PLUGIN_REGISTRY)
-    else:
-        # Fallback to eagerly initializing all built-in plugins.
-        seen = set()
-        for event_pattern, entries in PLUGIN_REGISTRY.items():
-            for entry in entries:
-                if entry not in seen:
-                    seen.add(entry)
-                    module_path, fn_name, entry_type = entry
-                    mod = importlib.import_module(module_path)
-                    fn = getattr(mod, fn_name)
-                    if entry_type == 'direct':
-                        handler = fn() if isinstance(fn, type) else fn
-                        event_handlers.register(event_pattern, handler)
-                    else:
-                        if isinstance(fn, type):
-                            fn(event_handlers)
-                        else:
-                            fn(event_handlers)
diff --git a/awscli/plugin.py b/awscli/plugin.py
index c2bf967a26f1..2544d5885403 100644
--- a/awscli/plugin.py
+++ b/awscli/plugin.py
@@ -14,11 +14,11 @@
 import os
 import sys
 
+from awscli.handlers_registry import PLUGIN_REGISTRY
 from awscli.lazy_emitter import LazyInitEmitter
 
 log = logging.getLogger('awscli.plugin')
 
-BUILTIN_PLUGINS = {'__builtin__': 'awscli.handlers'}
 CLI_LEGACY_PLUGIN_PATH = 'cli_legacy_plugin_path'
 
 
@@ -35,8 +35,8 @@ def load_plugins(plugin_mapping, event_hooks=None, include_builtins=True):
         passed in ``event_hooks`` will be used to initialize plugins.
 
     :type include_builtins: bool
-    :param include_builtins: If True, the builtin awscli plugins (specified in
-        ``BUILTIN_PLUGINS``) will be included in the list of plugins to load.
+    :param include_builtins: If True, the built-in plugin registry will be
+        loaded into the emitter.
 
     :rtype: LazyInitEmitter
     :return: An event emitter object.
@@ -45,7 +45,7 @@ def load_plugins(plugin_mapping, event_hooks=None, include_builtins=True):
     if event_hooks is None:
         event_hooks = LazyInitEmitter()
     if include_builtins:
-        _load_plugins(BUILTIN_PLUGINS, event_hooks)
+        event_hooks.load_registry(PLUGIN_REGISTRY)
     plugin_path = plugin_mapping.pop(CLI_LEGACY_PLUGIN_PATH, None)
     if plugin_path is not None:
         _add_plugin_path_to_sys_path(plugin_path)
diff --git a/tests/functional/test_handlers_registry.py b/tests/functional/test_handlers_registry.py
index c982f0d067ef..3b2049df53dd 100644
--- a/tests/functional/test_handlers_registry.py
+++ b/tests/functional/test_handlers_registry.py
@@ -15,7 +15,11 @@
 
 import botocore.session
 
-from awscli.handlers_registry import PLUGIN_REGISTRY
+from awscli.handlers_registry import (
+    CommandTableOp,
+    MAIN_COMMAND_TABLE_OPS,
+    PLUGIN_REGISTRY,
+)
 
 
 class _AuditEmitter:

From 369d8f410a47093bcbf152741cb31180807a1f31 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Fri, 29 May 2026 09:29:41 -0400
Subject: [PATCH 19/21] Add eager-loading fallback to plugin.py.

---
 awscli/plugin.py               | 21 ++++++++++++++++++++-
 exe/pyinstaller/hook-awscli.py |  2 +-
 tests/functional/test_lazy.py  |  6 +++---
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/awscli/plugin.py b/awscli/plugin.py
index 2544d5885403..73c44c3c2293 100644
--- a/awscli/plugin.py
+++ b/awscli/plugin.py
@@ -10,6 +10,7 @@
 # distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
 # ANY KIND, either express or implied. See the License for the specific
 # language governing permissions and limitations under the License.
+import importlib
 import logging
 import os
 import sys
@@ -45,7 +46,12 @@ def load_plugins(plugin_mapping, event_hooks=None, include_builtins=True):
     if event_hooks is None:
         event_hooks = LazyInitEmitter()
     if include_builtins:
-        event_hooks.load_registry(PLUGIN_REGISTRY)
+        if isinstance(event_hooks, LazyInitEmitter):
+            event_hooks.load_registry(PLUGIN_REGISTRY)
+        else:
+            # When the event emitter is not a LazyInitEmitter, we fall back
+            # to eagerly loading all plugins in the registry.
+            _eager_load_registry(event_hooks)
     plugin_path = plugin_mapping.pop(CLI_LEGACY_PLUGIN_PATH, None)
     if plugin_path is not None:
         _add_plugin_path_to_sys_path(plugin_path)
@@ -58,6 +64,19 @@ def load_plugins(plugin_mapping, event_hooks=None, include_builtins=True):
     return event_hooks
 
 
+def _eager_load_registry(event_hooks):
+    """Eagerly initialize all plugins from the plugin registry."""
+    seen = set()
+    for event_pattern, entries in PLUGIN_REGISTRY.items():
+        for entry in entries:
+            if entry not in seen:
+                seen.add(entry)
+                module_path, fn_name = entry
+                mod = importlib.import_module(module_path)
+                fn = getattr(mod, fn_name)
+                fn(event_hooks)
+
+
 def _load_plugins(plugin_mapping, event_hooks):
     modules = _import_plugins(plugin_mapping)
     for name, plugin in zip(plugin_mapping.keys(), modules):
diff --git a/exe/pyinstaller/hook-awscli.py b/exe/pyinstaller/hook-awscli.py
index 31a72dd3332e..5d284fabeae6 100644
--- a/exe/pyinstaller/hook-awscli.py
+++ b/exe/pyinstaller/hook-awscli.py
@@ -30,7 +30,7 @@
 ) + hooks.collect_submodules('awscli.s3transfer')
 hiddenimports += alias_packages_plugins
 
-# handlers.py uses importlib.import_module at runtime to load customization
+# plugin.py uses importlib.import_module at runtime to load customization
 # modules, so PyInstaller cannot discover them statically. Collect all module
 # paths referenced in handlers_registry.py as hidden imports.
 registry_modules = {
diff --git a/tests/functional/test_lazy.py b/tests/functional/test_lazy.py
index 3ba067e13aad..be134a98d8c8 100644
--- a/tests/functional/test_lazy.py
+++ b/tests/functional/test_lazy.py
@@ -12,13 +12,13 @@
 # language governing permissions and limitations under the License.
 import pytest
 
-from awscli.handlers_registry import MAIN_COMMAND_TABLE_OPS
+from awscli.handlers_registry import MAIN_COMMAND_TABLE_OPS, CommandTableOp
 from awscli.lazy import LazyCommand
 from awscli.testutils import BaseAWSHelpOutputTest, mock
 
 # Derive test parameters from MAIN_COMMAND_TABLE_OPS.
-_ADD_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == 'add']
-_RENAME_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == 'rename']
+_ADD_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == CommandTableOp.ADD]
+_RENAME_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == CommandTableOp.RENAME]
 _ADD_CMD_NAMES = [op[1] for op in _ADD_OPS]
 _RENAME_NEW_NAMES = [op[2] for op in _RENAME_OPS]
 

From 44c3ce9971ceb6bf88c8fa312535c787c27e83fa Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Fri, 29 May 2026 09:30:12 -0400
Subject: [PATCH 20/21] Formatting.

---
 tests/functional/test_handlers_registry.py | 2 +-
 tests/functional/test_lazy.py              | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/tests/functional/test_handlers_registry.py b/tests/functional/test_handlers_registry.py
index 3b2049df53dd..ec45094e44ac 100644
--- a/tests/functional/test_handlers_registry.py
+++ b/tests/functional/test_handlers_registry.py
@@ -16,9 +16,9 @@
 import botocore.session
 
 from awscli.handlers_registry import (
-    CommandTableOp,
     MAIN_COMMAND_TABLE_OPS,
     PLUGIN_REGISTRY,
+    CommandTableOp,
 )
 
 
diff --git a/tests/functional/test_lazy.py b/tests/functional/test_lazy.py
index be134a98d8c8..75cba38e5283 100644
--- a/tests/functional/test_lazy.py
+++ b/tests/functional/test_lazy.py
@@ -18,7 +18,9 @@
 
 # Derive test parameters from MAIN_COMMAND_TABLE_OPS.
 _ADD_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == CommandTableOp.ADD]
-_RENAME_OPS = [op for op in MAIN_COMMAND_TABLE_OPS if op[0] == CommandTableOp.RENAME]
+_RENAME_OPS = [
+    op for op in MAIN_COMMAND_TABLE_OPS if op[0] == CommandTableOp.RENAME
+]
 _ADD_CMD_NAMES = [op[1] for op in _ADD_OPS]
 _RENAME_NEW_NAMES = [op[2] for op in _RENAME_OPS]
 

From bf9aa0c731ac974fa4853215041d54010bc09b42 Mon Sep 17 00:00:00 2001
From: aemous <amoustafa0518@gmail.com>
Date: Fri, 29 May 2026 11:20:43 -0400
Subject: [PATCH 21/21] Switch to using single dispatch in plugin.py.

---
 awscli/plugin.py | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/awscli/plugin.py b/awscli/plugin.py
index 73c44c3c2293..fe41651c3d4f 100644
--- a/awscli/plugin.py
+++ b/awscli/plugin.py
@@ -14,6 +14,9 @@
 import logging
 import os
 import sys
+from functools import singledispatch
+
+from botocore.hooks import HierarchicalEmitter
 
 from awscli.handlers_registry import PLUGIN_REGISTRY
 from awscli.lazy_emitter import LazyInitEmitter
@@ -46,12 +49,7 @@ def load_plugins(plugin_mapping, event_hooks=None, include_builtins=True):
     if event_hooks is None:
         event_hooks = LazyInitEmitter()
     if include_builtins:
-        if isinstance(event_hooks, LazyInitEmitter):
-            event_hooks.load_registry(PLUGIN_REGISTRY)
-        else:
-            # When the event emitter is not a LazyInitEmitter, we fall back
-            # to eagerly loading all plugins in the registry.
-            _eager_load_registry(event_hooks)
+        _load_registry(event_hooks)
     plugin_path = plugin_mapping.pop(CLI_LEGACY_PLUGIN_PATH, None)
     if plugin_path is not None:
         _add_plugin_path_to_sys_path(plugin_path)
@@ -64,8 +62,16 @@ def load_plugins(plugin_mapping, event_hooks=None, include_builtins=True):
     return event_hooks
 
 
-def _eager_load_registry(event_hooks):
-    """Eagerly initialize all plugins from the plugin registry."""
+@singledispatch
+def _load_registry(event_hooks):
+    raise NotImplementedError(
+        f'No _load_registry implementation for '
+        f'{type(event_hooks).__name__}'
+    )
+
+
+@_load_registry.register
+def _(event_hooks: HierarchicalEmitter):
     seen = set()
     for event_pattern, entries in PLUGIN_REGISTRY.items():
         for entry in entries:
@@ -77,6 +83,11 @@ def _eager_load_registry(event_hooks):
                 fn(event_hooks)
 
 
+@_load_registry.register
+def _(event_hooks: LazyInitEmitter):
+    event_hooks.load_registry(PLUGIN_REGISTRY)
+
+
 def _load_plugins(plugin_mapping, event_hooks):
     modules = _import_plugins(plugin_mapping)
     for name, plugin in zip(plugin_mapping.keys(), modules):