diff --git a/buffet/commands/command_dictionary.cc b/buffet/commands/command_dictionary.cc
index f2b6f2f..3ab57a5 100644
--- a/buffet/commands/command_dictionary.cc
+++ b/buffet/commands/command_dictionary.cc
@@ -235,6 +235,12 @@
   return (pair != definitions_.end()) ? pair->second.get() : nullptr;
 }
 
+CommandDefinition* CommandDictionary::FindCommand(
+    const std::string& command_name) {
+  auto pair = definitions_.find(command_name);
+  return (pair != definitions_.end()) ? pair->second.get() : nullptr;
+}
+
 void CommandDictionary::Clear() {
   definitions_.clear();
 }
diff --git a/buffet/commands/command_dictionary.h b/buffet/commands/command_dictionary.h
index 52e1a10..7668fba 100644
--- a/buffet/commands/command_dictionary.h
+++ b/buffet/commands/command_dictionary.h
@@ -78,6 +78,7 @@
   void Clear();
   // Finds a definition for the given command.
   const CommandDefinition* FindCommand(const std::string& command_name) const;
+  CommandDefinition* FindCommand(const std::string& command_name);
 
  private:
   using CommandMap = std::map<std::string, std::unique_ptr<CommandDefinition>>;
diff --git a/buffet/commands/command_manager.cc b/buffet/commands/command_manager.cc
index 6facaf9..dd90e7d 100644
--- a/buffet/commands/command_manager.cc
+++ b/buffet/commands/command_manager.cc
@@ -104,4 +104,35 @@
   return command_queue_.Find(id);
 }
 
+bool CommandManager::SetCommandVisibility(
+    const std::vector<std::string>& command_names,
+    CommandDefinition::Visibility visibility,
+    chromeos::ErrorPtr* error) {
+  if (command_names.empty())
+    return true;
+
+  std::vector<CommandDefinition*> definitions;
+  definitions.reserve(command_names.size());
+
+  // Find/validate command definitions first.
+  for (const std::string& name : command_names) {
+    CommandDefinition* def = dictionary_.FindCommand(name);
+    if (!def) {
+      chromeos::Error::AddToPrintf(error, FROM_HERE, errors::commands::kDomain,
+                                   errors::commands::kInvalidCommandName,
+                                   "Command '%s' is unknown", name.c_str());
+      return false;
+    }
+    definitions.push_back(def);
+  }
+
+  // Now that we know that all the command names were valid,
+  // update the respective commands' visibility.
+  for (CommandDefinition* def : definitions) {
+    def->SetVisibility(visibility);
+  }
+  on_command_changed_.Notify();
+  return true;
+}
+
 }  // namespace buffet
diff --git a/buffet/commands/command_manager.h b/buffet/commands/command_manager.h
index 3e23cbf..072d055 100644
--- a/buffet/commands/command_manager.h
+++ b/buffet/commands/command_manager.h
@@ -7,6 +7,7 @@
 
 #include <memory>
 #include <string>
+#include <vector>
 
 #include <base/callback.h>
 #include <base/callback_list.h>
@@ -49,7 +50,8 @@
   explicit CommandManager(CommandDispachInterface* dispatch_interface);
 
   // Sets callback which is called when command definitions is changed.
-  CallbackToken AddOnCommandDefChanged(const base::Closure& callback) {
+  CallbackToken AddOnCommandDefChanged(
+      const base::Closure& callback) WARN_UNUSED_RESULT {
     return CallbackToken{on_command_changed_.Add(callback).release()};
   }
 
@@ -102,6 +104,11 @@
   // for a long period of time.
   CommandInstance* FindCommand(const std::string& id) const;
 
+  // Changes the visibility of commands.
+  bool SetCommandVisibility(const std::vector<std::string>& command_names,
+                            CommandDefinition::Visibility visibility,
+                            chromeos::ErrorPtr* error);
+
  private:
   CommandDictionary base_dictionary_;  // Base/std command definitions/schemas.
   CommandDictionary dictionary_;  // Command definitions/schemas.
diff --git a/buffet/commands/command_manager_unittest.cc b/buffet/commands/command_manager_unittest.cc
index 2d4fed8..57e0d06 100644
--- a/buffet/commands/command_manager_unittest.cc
+++ b/buffet/commands/command_manager_unittest.cc
@@ -7,6 +7,7 @@
 #include <base/files/file_util.h>
 #include <base/files/scoped_temp_dir.h>
 #include <base/json/json_writer.h>
+#include <chromeos/bind_lambda.h>
 #include <gtest/gtest.h>
 
 #include "buffet/commands/unittest_utils.h"
@@ -156,3 +157,61 @@
   EXPECT_NE(nullptr,
             manager.GetCommandDictionary().FindCommand("test._yo"));
 }
+
+TEST(CommandManager, UpdateCommandVisibility) {
+  buffet::CommandManager manager;
+  int update_count = 0;
+  auto on_command_change = [&update_count]() { update_count++; };
+  auto token = manager.AddOnCommandDefChanged(base::Bind(on_command_change));
+
+  auto json = CreateDictionaryValue(R"({
+    'foo': {
+      '_baz': {
+        'parameters': {},
+        'results': {}
+      },
+      '_bar': {
+        'parameters': {},
+        'results': {}
+      }
+    },
+    'bar': {
+      '_quux': {
+        'parameters': {},
+        'results': {},
+        'visibility': 'none'
+      }
+    }
+  })");
+  ASSERT_TRUE(manager.LoadCommands(*json, "test", nullptr));
+  EXPECT_EQ(1, update_count);
+  const buffet::CommandDictionary& dict = manager.GetCommandDictionary();
+  EXPECT_TRUE(manager.SetCommandVisibility(
+      {"foo._baz"},
+      buffet::CommandDefinition::Visibility::GetLocal(), nullptr));
+  EXPECT_EQ(2, update_count);
+  EXPECT_EQ("local", dict.FindCommand("foo._baz")->GetVisibility().ToString());
+  EXPECT_EQ("all", dict.FindCommand("foo._bar")->GetVisibility().ToString());
+  EXPECT_EQ("none", dict.FindCommand("bar._quux")->GetVisibility().ToString());
+
+  chromeos::ErrorPtr error;
+  ASSERT_FALSE(manager.SetCommandVisibility(
+      {"foo._baz", "foo._bar", "test.cmd"},
+      buffet::CommandDefinition::Visibility::GetLocal(), &error));
+  EXPECT_EQ(buffet::errors::commands::kInvalidCommandName, error->GetCode());
+  EXPECT_EQ("Command 'test.cmd' is unknown", error->GetMessage());
+  // The visibility state of commands shouldn't have changed.
+  EXPECT_EQ(2, update_count);
+  EXPECT_EQ("local", dict.FindCommand("foo._baz")->GetVisibility().ToString());
+  EXPECT_EQ("all", dict.FindCommand("foo._bar")->GetVisibility().ToString());
+  EXPECT_EQ("none", dict.FindCommand("bar._quux")->GetVisibility().ToString());
+
+  EXPECT_TRUE(manager.SetCommandVisibility(
+      {"foo._baz", "bar._quux"},
+      buffet::CommandDefinition::Visibility::GetCloud(), nullptr));
+  EXPECT_EQ(3, update_count);
+  EXPECT_EQ("cloud", dict.FindCommand("foo._baz")->GetVisibility().ToString());
+  EXPECT_EQ("all", dict.FindCommand("foo._bar")->GetVisibility().ToString());
+  EXPECT_EQ("cloud", dict.FindCommand("bar._quux")->GetVisibility().ToString());
+}
+