diff --git a/buffet/commands/command_definition.cc b/buffet/commands/command_definition.cc
index c5854c2..02b7722 100644
--- a/buffet/commands/command_definition.cc
+++ b/buffet/commands/command_definition.cc
@@ -4,14 +4,70 @@
 
 #include "buffet/commands/command_definition.h"
 
+#include <vector>
+
+#include <chromeos/errors/error.h>
+#include <chromeos/strings/string_utils.h>
+
+#include "buffet/commands/schema_constants.h"
+
 namespace buffet {
 
+bool CommandDefinition::Visibility::FromString(const std::string& str,
+                                               chromeos::ErrorPtr* error) {
+  // This special case is useful for places where we want to make a command
+  // to ALL clients, even if new clients are added in the future.
+  if (str == commands::attributes::kCommand_Visibility_All) {
+    local = true;
+    cloud = true;
+    return true;
+  }
+
+  // Clear any bits first.
+  local = false;
+  cloud = false;
+  if (str == commands::attributes::kCommand_Visibility_None)
+    return true;
+
+  for (const std::string& value : chromeos::string_utils::Split(str, ",")) {
+    if (value == commands::attributes::kCommand_Visibility_Local) {
+      local = true;
+    } else if (value == commands::attributes::kCommand_Visibility_Cloud) {
+      cloud = true;
+    } else {
+      chromeos::Error::AddToPrintf(
+          error, FROM_HERE, errors::commands::kDomain,
+          errors::commands::kInvalidPropValue,
+          "Invalid command visibility value '%s'", value.c_str());
+      return false;
+    }
+  }
+  return true;
+}
+
+std::string CommandDefinition::Visibility::ToString() const {
+  if (local && cloud)
+    return commands::attributes::kCommand_Visibility_All;
+  if (!local && !cloud)
+    return commands::attributes::kCommand_Visibility_None;
+  if (local)
+    return commands::attributes::kCommand_Visibility_Local;
+  return commands::attributes::kCommand_Visibility_Cloud;
+}
+
 CommandDefinition::CommandDefinition(
     const std::string& category,
     std::unique_ptr<const ObjectSchema> parameters,
     std::unique_ptr<const ObjectSchema> results)
         : category_{category},
           parameters_{std::move(parameters)},
-          results_{std::move(results)} {}
+          results_{std::move(results)} {
+  // Set to be available to all clients by default.
+  visibility_ = Visibility::GetAll();
+}
+
+void CommandDefinition::SetVisibility(const Visibility& visibility) {
+  visibility_ = visibility;
+}
 
 }  // namespace buffet