diff --git a/buffet/transport_interface.h b/buffet/transport_interface.h
new file mode 100644
index 0000000..fa858c6
--- /dev/null
+++ b/buffet/transport_interface.h
@@ -0,0 +1,79 @@
+// 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.
+
+#ifndef BUFFET_TRANSPORT_INTERFACE_H_
+#define BUFFET_TRANSPORT_INTERFACE_H_
+
+#include <vector>
+#include <string>
+#include <base/basictypes.h>
+
+namespace chromeos {
+namespace http {
+
+///////////////////////////////////////////////////////////////////////////////
+// TransportInterface is an interface to abstract specific implementation
+// of HTTP communication. This interface (and its underlying implementation)
+// is used by http::Request and http::Response classes to provide HTTP
+// functionality to the clients. This interface should be of no interest
+// to the clients unless they want to implement/use their own network library.
+///////////////////////////////////////////////////////////////////////////////
+class TransportInterface {
+ public:
+  enum class Stage {
+    initialized,
+    response_received,
+    failed,
+    closed
+  };
+
+  virtual ~TransportInterface() {}
+
+  virtual Stage GetStage() const = 0;
+
+  virtual void AddRange(int64_t bytes) = 0;
+  virtual void AddRange(uint64_t from_byte, uint64_t to_byte) = 0;
+
+  virtual void SetAccept(char const* accept_mime_types) = 0;
+  virtual std::string GetAccept() const = 0;
+
+  virtual std::string GetRequestURL() const = 0;
+
+  virtual void SetContentType(char const* content_type) = 0;
+  virtual std::string GetContentType() const = 0;
+
+  virtual void AddHeader(char const* header, char const* value) = 0;
+  virtual void RemoveHeader(char const* header) = 0;
+
+  virtual bool AddRequestBody(void const* data, size_t size) = 0;
+
+  virtual void SetMethod(char const* method) = 0;
+  virtual std::string GetMethod() const = 0;
+
+  virtual void SetReferer(char const* referer) = 0;
+  virtual std::string GetReferer() const = 0;
+
+  virtual void SetUserAgent(char const* user_agent) = 0;
+  virtual std::string GetUserAgent() const = 0;
+
+  virtual bool Perform() = 0;
+
+  virtual int GetResponseStatusCode() const = 0;
+  virtual std::string GetResponseStatusText() const = 0;
+
+  virtual std::string GetResponseHeader(char const* header_name) const = 0;
+  virtual std::vector<unsigned char> const& GetResponseData() const = 0;
+  virtual std::string GetErrorMessage() const = 0;
+
+  virtual void Close() = 0;
+
+ protected:
+  TransportInterface() {}
+  DISALLOW_COPY_AND_ASSIGN(TransportInterface);
+};
+
+} // namespace http
+} // namespace chromeos
+
+#endif // BUFFET_TRANSPORT_INTERFACE_H_