diff --git a/buffet/commands/schema_constants.cc b/buffet/commands/schema_constants.cc
new file mode 100644
index 0000000..15d6db3
--- /dev/null
+++ b/buffet/commands/schema_constants.cc
@@ -0,0 +1,36 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "buffet/commands/schema_constants.h"
+
+namespace buffet {
+namespace commands {
+
+namespace errors {
+const char kDomain[]            = "command_schema";
+
+const char kOutOfRange[]        = "out_of_range";
+const char kTypeMismatch[]      = "type_mismatch";
+const char kPropTypeChanged[]   = "param_type_changed";
+const char kUnknownType[]       = "unknown_type";
+const char kInvalidPropDef[]    = "invalid_parameter_definition";
+const char kNoTypeInfo[]        = "no_type_info";
+const char kPropertyMissing[]   = "parameter_missing";
+}  // namespace errors
+
+namespace attributes {
+const char kType[]              = "type";
+const char kDisplayName[]       = "displayName";
+
+const char kNumeric_Min[]       = "minimum";
+const char kNumeric_Max[]       = "maximum";
+
+const char kString_MinLength[]  = "minLength";
+const char kString_MaxLength[]  = "maxLength";
+
+const char kOneOf_Enum[]        = "enum";
+}  // namespace attributes
+
+}  // namespace commands
+}  // namespace buffet