diff --git a/tools/pyproject.toml b/tools/pyproject.toml
index eeba9ee4..055391d9 100644
--- a/tools/pyproject.toml
+++ b/tools/pyproject.toml
@@ -27,7 +27,7 @@ classifiers = [
 dependencies = [
     "attrs >= 25.3, < 26.2",
     "certifi >= 2024, < 2027",
-    "click == 7.1.2",
+    "click == 8.5.0",
     "click-configfile == 0.2.3",
     "configparser >= 7.2, < 7.3",
     "dvp-libs == 5.2.0",
@@ -52,7 +52,7 @@ dev = [
     "entrypoints == 0.4",
     "flake8 == 7.3.0",
     "httpretty == 1.1.4",
-    "isort == 8.0.1",
+    "isort == 9.0.2",
     "mccabe == 0.7.0",
     "mock == 5.2.0",
     "more-itertools == 11.1.0",
diff --git a/tools/src/main/python/dlpx/virtualization/_internal/cli.py b/tools/src/main/python/dlpx/virtualization/_internal/cli.py
index 850ab757..b513bf14 100644
--- a/tools/src/main/python/dlpx/virtualization/_internal/cli.py
+++ b/tools/src/main/python/dlpx/virtualization/_internal/cli.py
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2019, 2021 by Delphix. All rights reserved.
+# Copyright (c) 2019, 2026 by Delphix. All rights reserved.
 #
 
 import logging
@@ -64,7 +64,7 @@ def command_error_handler():
         exit(2)
 
 
-@click.group(context_settings=CONTEXT_SETTINGS)
+@click.group(context_settings=CONTEXT_SETTINGS, invoke_without_command=True)
 @click.version_option(__version__)
 @click.option(
     '-v',
@@ -84,7 +84,8 @@ def command_error_handler():
     type=click.IntRange(0, 3),
     help=('Enable quiet mode. '
           'Can be repeated up to three times for increased suppression.'))
-def delphix_sdk(verbose, quiet):
+@click.pass_context
+def delphix_sdk(ctx, verbose, quiet):
     """
     The tools of the Delphix Virtualization SDK that help develop, build, and
     upload a plugin.
@@ -100,6 +101,16 @@ def delphix_sdk(verbose, quiet):
             'Python version check failed.'
             'Supported version is 3.11.x, found {}'
             .format(sys.version_info))
+    #
+    # Click >= 8.1 treats a group invoked with no subcommand as a usage
+    # error (exit code 2) instead of printing help and exiting 0 as Click
+    # 7.x did. invoke_without_command=True skips that check, so replicate
+    # the old exit-0/help behavior explicitly here to keep it unchanged
+    # for anything scripting around a bare `dvp` invocation.
+    #
+    if ctx.invoked_subcommand is None:
+        click.echo(ctx.get_help())
+        ctx.exit()
 
 
 @delphix_sdk.command(context_settings=CONTEXT_SETTINGS_INIT)
@@ -108,11 +119,11 @@ def delphix_sdk(verbose, quiet):
               'root',
               default=os.getcwd(),
               show_default=True,
-              type=click.Path(exists=True,
-                              file_okay=False,
-                              dir_okay=True,
-                              writable=True,
-                              resolve_path=True),
+              type=click_util.NonEmptyPath(exists=True,
+                                           file_okay=False,
+                                           dir_okay=True,
+                                           writable=True,
+                                           resolve_path=True),
               callback=click_util.validate_option_exists,
               help='Set the plugin root directory.')
 @click.option('-n',
@@ -297,11 +308,11 @@ def upload(engine, user, upload_artifact, password, wait):
     '--directory',
     default=os.getcwd(),
     show_default=True,
-    type=click.Path(exists=True,
-                    file_okay=False,
-                    dir_okay=True,
-                    writable=True,
-                    resolve_path=True),
+    type=click_util.NonEmptyPath(exists=True,
+                                 file_okay=False,
+                                 dir_okay=True,
+                                 writable=True,
+                                 resolve_path=True),
     callback=click_util.validate_option_exists,
     help='Specify the directory of where to download the plugin logs.')
 @click.password_option(cls=click_util.PasswordPromptIf,
diff --git a/tools/src/main/python/dlpx/virtualization/_internal/click_util.py b/tools/src/main/python/dlpx/virtualization/_internal/click_util.py
index b8b0941c..e606bcd5 100644
--- a/tools/src/main/python/dlpx/virtualization/_internal/click_util.py
+++ b/tools/src/main/python/dlpx/virtualization/_internal/click_util.py
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2019 by Delphix. All rights reserved.
+# Copyright (c) 2019, 2026 by Delphix. All rights reserved.
 #
 
 import os
@@ -72,6 +72,22 @@ def validate_option_exists(ctx, param, value):
     return value
 
 
+class NonEmptyPath(click.Path):
+    """
+    A click.Path that rejects an empty string outright. Click >= 8.0
+    resolves an empty string to the current working directory before
+    running its exists/writable checks (via os.path.realpath('')), so an
+    empty value for a Path option with resolve_path=True silently passes
+    instead of failing as it did on Click 7.x.
+    """
+    def convert(self, value, param, ctx):
+        if value == '':
+            self.fail(
+                '{} {!r} does not exist.'.format(self.name.title(), value),
+                param, ctx)
+        return super(NonEmptyPath, self).convert(value, param, ctx)
+
+
 class MutuallyExclusiveOption(click.Option):
     """
     A Click Option type that is mutually exclusive with another option. Click
diff --git a/tools/src/test/python/dlpx/virtualization/_internal/test_cli.py b/tools/src/test/python/dlpx/virtualization/_internal/test_cli.py
index 2ec8ad0b..6567ead7 100644
--- a/tools/src/test/python/dlpx/virtualization/_internal/test_cli.py
+++ b/tools/src/test/python/dlpx/virtualization/_internal/test_cli.py
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2019, 2021 by Delphix. All rights reserved.
+# Copyright (c) 2019, 2026 by Delphix. All rights reserved.
 #
 
 import os
@@ -18,6 +18,9 @@ class TestCli:
     def test_default_verbosity():
         runner = click_testing.CliRunner()
 
+        # Click >= 8.1 would otherwise exit 2 (usage error) here instead of
+        # 0 as in Click 7.x; delphix_sdk explicitly restores the old
+        # help/exit-0 behavior for a bare invocation with no subcommand.
         result = runner.invoke(cli.delphix_sdk)
 
         assert result.exit_code == 0, 'Output: {}'.format(result.output)
@@ -337,7 +340,7 @@ def test_file_not_exist(plugin_config_file):
 
         assert result.exit_code == 2
         assert result.output == (u"Usage: delphix-sdk build [OPTIONS]"
-                                 u"\nTry 'delphix-sdk build -h' for help."
+                                 u"\nTry 'delphix-sdk build --help' for help."
                                  u"\n"
                                  u"\nError: Invalid value for '-c' /"
                                  u" '--plugin-config': File"
@@ -517,7 +520,7 @@ def test_file_not_exist(artifact_file):
 
         assert result.exit_code == 2
         assert result.output == (u"Usage: delphix-sdk upload [OPTIONS]"
-                                 u"\nTry 'delphix-sdk upload -h' for help."
+                                 u"\nTry 'delphix-sdk upload --help' for help."
                                  u"\n"
                                  u"\nError: Invalid value for '-a' /"
                                  u" '--upload-artifact': File"
@@ -698,7 +701,7 @@ def test_directory_not_exist(directory):
         assert result.exit_code == 2
         assert result.output == (
             u"Usage: delphix-sdk download-logs [OPTIONS]"
-            u"\nTry 'delphix-sdk download-logs -h' for help."
+            u"\nTry 'delphix-sdk download-logs --help' for help."
             u"\n"
             u"\nError: Invalid value for '-d' /"
             u" '--directory': Directory"
@@ -706,6 +709,25 @@ def test_directory_not_exist(directory):
             u" does not exist."
             u"\n")
 
+    @staticmethod
+    def test_empty_directory():
+        # Click >= 8.0 resolves an empty string to the current working
+        # directory before running its exists/writable checks, so this
+        # would otherwise silently pass instead of erroring as it did on
+        # Click 7.x; NonEmptyPath (click_util.py) restores that rejection.
+        engine = 'engine'
+        user = 'admin'
+        password = 'delphix'
+
+        runner = click_testing.CliRunner()
+        result = runner.invoke(cli.delphix_sdk, [
+            'download-logs', '-e', engine, '-u', user, '--password', password,
+            '-d', ''
+        ])
+
+        assert result.exit_code != 0
+        assert "Invalid value for '-d'" in result.output
+
     @staticmethod
     @pytest.mark.parametrize('plugin_config_file',
                              ['/not/a/real/file/plugin_config.yml'])
@@ -724,7 +746,7 @@ def test_file_not_exist(plugin_config_file):
         assert result.exit_code == 2
         assert result.output == (
             u"Usage: delphix-sdk download-logs [OPTIONS]"
-            u"\nTry 'delphix-sdk download-logs -h' for help."
+            u"\nTry 'delphix-sdk download-logs --help' for help."
             u"\n"
             u"\nError: Invalid value for '-c' /"
             u" '--plugin-config': File"