diff --git a/src/repo-command.cpp b/src/repo-command.cpp
new file mode 100644
index 0000000..b8200d5
--- /dev/null
+++ b/src/repo-command.cpp
@@ -0,0 +1,127 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2018, Regents of the University of California.
+ *
+ * This file is part of NDN repo-ng (Next generation of NDN repository).
+ * See AUTHORS.md for complete list of repo-ng authors and contributors.
+ *
+ * repo-ng is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * repo-ng is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * repo-ng, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "repo-command.hpp"
+
+namespace repo {
+
+void
+RepoCommand::validateRequest(const RepoCommandParameter& parameters) {
+  m_requestValidator.validate(parameters);
+  check(parameters);
+}
+
+void
+RepoCommand::FieldValidator::validate(const RepoCommandParameter& parameters) const
+{
+  const std::vector<bool>& presentFields = parameters.getPresentFields();
+
+  for (size_t i = 0; i < REPO_PARAMETER_UBOUND; i++) {
+    bool isPresent = presentFields[i];
+    if (m_required[i]) {
+      if (!isPresent) {
+        BOOST_THROW_EXCEPTION(ArgumentError(REPO_PARAMETER_FIELD[i] + " is required but missing"));
+      }
+    }
+    else if (isPresent && !m_optional[i]) {
+      BOOST_THROW_EXCEPTION(ArgumentError(REPO_PARAMETER_FIELD[i] + " is forbidden but present"));
+    }
+  }
+}
+
+RepoCommand::FieldValidator::FieldValidator()
+  : m_required(REPO_PARAMETER_UBOUND)
+  , m_optional(REPO_PARAMETER_UBOUND)
+{
+}
+
+InsertCommand::InsertCommand()
+: RepoCommand()
+{
+  m_requestValidator
+    .required(REPO_PARAMETER_NAME)
+    .required(REPO_PARAMETER_START_BLOCK_ID)
+    .required(REPO_PARAMETER_END_BLOCK_ID);
+}
+
+InsertCheckCommand::InsertCheckCommand()
+{
+  m_requestValidator
+    .required(REPO_PARAMETER_NAME)
+    .required(REPO_PARAMETER_PROCESS_ID);
+}
+
+WatchStartCommand::WatchStartCommand()
+{
+  m_requestValidator
+    .required(REPO_PARAMETER_NAME)
+    .optional(REPO_PARAMETER_INTEREST_LIFETIME)
+    .optional(REPO_PARAMETER_MAX_INTEREST_NUM)
+    .optional(REPO_PARAMETER_WATCH_TIME_OUT);
+}
+
+WatchCheckCommand::WatchCheckCommand()
+{
+  m_requestValidator
+    .required(REPO_PARAMETER_NAME);
+}
+
+WatchStopCommand::WatchStopCommand()
+{
+  m_requestValidator
+    .required(REPO_PARAMETER_NAME);
+}
+
+DeleteCommand::DeleteCommand()
+{
+  m_requestValidator
+    .required(REPO_PARAMETER_NAME)
+    .required(REPO_PARAMETER_START_BLOCK_ID)
+    .required(REPO_PARAMETER_END_BLOCK_ID)
+    .required(REPO_PARAMETER_PROCESS_ID);
+}
+void
+InsertCommand::check(const RepoCommandParameter& parameters) const
+{
+  if (parameters.hasStartBlockId() || parameters.hasEndBlockId()) {
+    if (parameters.hasSelectors()) {
+      BOOST_THROW_EXCEPTION(ArgumentError("BlockId present. BlockId is not supported in this protocol"));
+      return;
+    }
+  }
+}
+
+void
+DeleteCommand::check(const RepoCommandParameter& parameters) const
+{
+  if (parameters.hasStartBlockId() || parameters.hasEndBlockId()) {
+    if (parameters.hasEndBlockId()) {
+      SegmentNo startBlockId = parameters.getStartBlockId();
+      SegmentNo endBlockId = parameters.getEndBlockId();
+
+      if (startBlockId > endBlockId) {
+        BOOST_THROW_EXCEPTION(ArgumentError("start block Id is bigger than end block Id"));
+      }
+    }
+    else {
+      BOOST_THROW_EXCEPTION(ArgumentError("Segmented deletion without EndBlockId, not implemented"));
+    }
+  }
+}
+} // namespace repo
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