diff --git a/buffet/commands/object_schema.cc b/buffet/commands/object_schema.cc
new file mode 100644
index 0000000..19610be
--- /dev/null
+++ b/buffet/commands/object_schema.cc
@@ -0,0 +1,251 @@
+// 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/object_schema.h"
+
+#include <algorithm>
+#include <limits>
+#include <set>
+
+#include <base/json/json_writer.h>
+#include <base/logging.h>
+#include <base/values.h>
+
+#include "buffet/commands/prop_types.h"
+#include "buffet/commands/prop_values.h"
+#include "buffet/commands/schema_constants.h"
+
+namespace buffet {
+
+void ObjectSchema::AddProp(const std::string& name,
+                           std::shared_ptr<PropType> prop) {
+  properties_[name] = prop;
+}
+
+const PropType* ObjectSchema::GetProp(const std::string& name) const {
+  auto p = properties_.find(name);
+  return p != properties_.end() ? p->second.get() : nullptr;
+}
+
+std::unique_ptr<base::DictionaryValue> ObjectSchema::ToJson(
+    bool full_schema, ErrorPtr* error) const {
+  std::unique_ptr<base::DictionaryValue> value(new base::DictionaryValue);
+  for (const auto& pair : properties_) {
+    auto PropDef = pair.second->ToJson(full_schema, error);
+    if (!PropDef)
+      return std::unique_ptr<base::DictionaryValue>();
+    value->SetWithoutPathExpansion(pair.first, PropDef.release());
+  }
+  return value;
+}
+
+bool ObjectSchema::FromJson(const base::DictionaryValue* value,
+                            const ObjectSchema* schema, ErrorPtr* error) {
+  Properties properties;
+  base::DictionaryValue::Iterator iter(*value);
+  while (!iter.IsAtEnd()) {
+    std::string name = iter.key();
+    const PropType* schemaProp = schema ? schema->GetProp(iter.key()) :
+                                          nullptr;
+    if (!PropFromJson(iter.key(), iter.value(), schemaProp, &properties,
+                      error))
+      return false;
+    iter.Advance();
+  }
+  properties_ = std::move(properties);
+  return true;
+}
+
+static std::unique_ptr<PropType> CreatePropType(const std::string& type_name,
+                                                const std::string& prop_name,
+                                                ErrorPtr* error) {
+  std::unique_ptr<PropType> prop;
+  ValueType type;
+  if (PropType::GetTypeFromTypeString(type_name, &type))
+    prop = PropType::Create(type);
+  if (!prop) {
+    Error::AddToPrintf(error, commands::errors::kDomain,
+                       commands::errors::kUnknownType,
+                       "Unknown type %s for parameter %s",
+                       type_name.c_str(), prop_name.c_str());
+  }
+  return prop;
+}
+
+static bool ErrorInvalidTypeInfo(const std::string& prop_name,
+                                 ErrorPtr* error) {
+  Error::AddToPrintf(error, commands::errors::kDomain,
+                     commands::errors::kNoTypeInfo,
+                     "Unable to determine parameter type for %s",
+                     prop_name.c_str());
+  return false;
+}
+
+bool ObjectSchema::PropFromJson(const std::string& prop_name,
+                                const base::Value& value,
+                                const PropType* schemaProp,
+                                Properties* properties,
+                                ErrorPtr* error) const {
+  if (value.IsType(base::Value::TYPE_STRING)) {
+    // A string value is a short-hand object specification and provides
+    // the parameter type.
+    return PropFromJsonString(prop_name, value, schemaProp, properties,
+                              error);
+  } else if (value.IsType(base::Value::TYPE_LIST)) {
+    // One of the enumerated types.
+    return PropFromJsonArray(prop_name, value, schemaProp, properties,
+                             error);
+  } else if (value.IsType(base::Value::TYPE_DICTIONARY)) {
+    // Full parameter definition.
+    return PropFromJsonObject(prop_name, value, schemaProp, properties,
+                              error);
+  }
+  Error::AddToPrintf(error, commands::errors::kDomain,
+                     commands::errors::kInvalidPropDef,
+                     "Invalid parameter definition for %s", prop_name.c_str());
+  return false;
+}
+
+bool ObjectSchema::PropFromJsonString(const std::string& prop_name,
+                                      const base::Value& value,
+                                      const PropType* schemaProp,
+                                      Properties* properties,
+                                      ErrorPtr* error) const {
+  std::string type_name;
+  CHECK(value.GetAsString(&type_name)) << "Unable to get string value";
+  std::unique_ptr<PropType> prop = CreatePropType(type_name, prop_name, error);
+  if (!prop)
+    return false;
+  base::DictionaryValue empty;
+  if (!prop->FromJson(&empty, schemaProp, error))
+    return false;
+  properties->insert(std::make_pair(prop_name, std::move(prop)));
+  return true;
+}
+
+static std::string DetectArrayType(const base::ListValue* list,
+                                   const PropType* schemaProp) {
+  std::string type_name;
+  if (schemaProp) {
+    type_name = schemaProp->GetTypeAsString();
+  } else if (list->GetSize() > 0) {
+    const base::Value* first_element = nullptr;
+    if (list->Get(0, &first_element)) {
+      switch (first_element->GetType()) {
+      case base::Value::TYPE_BOOLEAN:
+        type_name = PropType::GetTypeStringFromType(ValueType::Boolean);
+        break;
+      case base::Value::TYPE_INTEGER:
+        type_name = PropType::GetTypeStringFromType(ValueType::Int);
+        break;
+      case base::Value::TYPE_DOUBLE:
+        type_name = PropType::GetTypeStringFromType(ValueType::Double);
+        break;
+      case base::Value::TYPE_STRING:
+        type_name = PropType::GetTypeStringFromType(ValueType::String);
+        break;
+      default:
+        // The rest are unsupported.
+        break;
+      }
+    }
+  }
+  return type_name;
+}
+
+bool ObjectSchema::PropFromJsonArray(const std::string& prop_name,
+                                     const base::Value& value,
+                                     const PropType* schemaProp,
+                                     Properties* properties,
+                                     ErrorPtr* error) const {
+  const base::ListValue* list = nullptr;
+  CHECK(value.GetAsList(&list)) << "Unable to get array value";
+  std::string type_name = DetectArrayType(list, schemaProp);
+  if (type_name.empty())
+    return ErrorInvalidTypeInfo(prop_name, error);
+  std::unique_ptr<PropType> prop = CreatePropType(type_name, prop_name, error);
+  if (!prop)
+    return false;
+  base::DictionaryValue array_object;
+  array_object.SetWithoutPathExpansion(commands::attributes::kOneOf_Enum,
+                                       list->DeepCopy());
+  if (!prop->FromJson(&array_object, schemaProp, error))
+    return false;
+  properties->insert(std::make_pair(prop_name, std::move(prop)));
+  return true;
+}
+
+static std::string DetectObjectType(const base::DictionaryValue* dict,
+                                    const PropType* schemaProp) {
+  bool has_min_max = dict->HasKey(commands::attributes::kNumeric_Min) ||
+                     dict->HasKey(commands::attributes::kNumeric_Max);
+
+  // Here we are trying to "detect the type and read in the object based on
+  // the deduced type". Later, we'll verify that this detected type matches
+  // the expectation of the base schema, if applicable, to make sure we are not
+  // changing the expected type. This makes the vendor-side (re)definition of
+  // standard and custom commands behave exactly the same.
+  // The only problem with this approach was the double-vs-int types.
+  // If the type is meant to be a double we want to allow its definition as
+  // "min:0, max:0" instead of just forcing it to be only "min:0.0, max:0.0".
+  // If we have "minimum" or "maximum", and we have a Double schema object,
+  // treat this object as a Double (even if both min and max are integers).
+  if (has_min_max && schemaProp && schemaProp->GetType() == ValueType::Double)
+    return PropType::GetTypeStringFromType(ValueType::Double);
+
+  // If we have at least one "minimum" or "maximum" that is Double,
+  // it's a Double.
+  const base::Value* value = nullptr;
+  if (dict->Get(commands::attributes::kNumeric_Min, &value) &&
+      value->IsType(base::Value::TYPE_DOUBLE))
+    return PropType::GetTypeStringFromType(ValueType::Double);
+  if (dict->Get(commands::attributes::kNumeric_Max, &value) &&
+      value->IsType(base::Value::TYPE_DOUBLE))
+    return PropType::GetTypeStringFromType(ValueType::Double);
+
+  // If we have "minimum" or "maximum", it's an Integer.
+  if (has_min_max)
+    return PropType::GetTypeStringFromType(ValueType::Int);
+
+  // If we have "minLength" or "maxLength", it's a String.
+  if (dict->HasKey(commands::attributes::kString_MinLength) ||
+      dict->HasKey(commands::attributes::kString_MaxLength))
+    return PropType::GetTypeStringFromType(ValueType::String);
+
+  // If we have "values", it's an array.
+  const base::ListValue* list = nullptr;
+  if (dict->GetListWithoutPathExpansion(
+      commands::attributes::kOneOf_Enum, &list))
+    return DetectArrayType(list, schemaProp);
+
+  return std::string();
+}
+
+bool ObjectSchema::PropFromJsonObject(const std::string& prop_name,
+                                      const base::Value& value,
+                                      const PropType* schemaProp,
+                                      Properties* properties,
+                                      ErrorPtr* error) const {
+  const base::DictionaryValue* dict = nullptr;
+  CHECK(value.GetAsDictionary(&dict)) << "Unable to get dictionary value";
+  std::string type_name;
+  if (dict->HasKey(commands::attributes::kType)) {
+    if (!dict->GetString(commands::attributes::kType, &type_name))
+      return ErrorInvalidTypeInfo(prop_name, error);
+  } else {
+    type_name = DetectObjectType(dict, schemaProp);
+  }
+  if (type_name.empty()) {
+    if (!schemaProp)
+      return ErrorInvalidTypeInfo(prop_name, error);
+    type_name = schemaProp->GetTypeAsString();
+  }
+  std::unique_ptr<PropType> prop = CreatePropType(type_name, prop_name, error);
+  if (!prop || !prop->FromJson(dict, schemaProp, error))
+    return false;
+  properties->insert(std::make_pair(prop_name, std::move(prop)));
+  return true;
+}
+
+}  // namespace buffet