diff --git a/grive/src/main.cc b/grive/src/main.cc
index d51e0d9..47947f3 100644
--- a/grive/src/main.cc
+++ b/grive/src/main.cc
@@ -21,6 +21,8 @@
 
 #include "drive/Drive.hh"
 
+#include "http/CurlAgent.hh"
+#include "protocol/AuthAgent.hh"
 #include "protocol/OAuth2.hh"
 #include "protocol/Json.hh"
 
@@ -172,7 +174,8 @@ int Main( int argc, char **argv )
 	}
 	
 	OAuth2 token( refresh_token, client_id, client_secret ) ;
-	Drive drive( token, options ) ;
+	AuthAgent agent( token, std::auto_ptr<http::Agent>( new http::CurlAgent ) ) ;
+	Drive drive( &agent, options ) ;
 	drive.DetectChanges() ;
 
 	if ( vm.count( "dry-run" ) == 0 )
diff --git a/libgrive/src/drive/Drive.cc b/libgrive/src/drive/Drive.cc
index f0d454f..daf0a72 100644
--- a/libgrive/src/drive/Drive.cc
+++ b/libgrive/src/drive/Drive.cc
@@ -23,11 +23,11 @@
 #include "Entry.hh"
 #include "Feed.hh"
 
-#include "http/CurlAgent.hh"
+#include "http/Agent.hh"
 #include "http/ResponseLog.hh"
 #include "http/XmlResponse.hh"
 #include "protocol/Json.hh"
-#include "protocol/OAuth2.hh"
+// #include "protocol/OAuth2.hh"
 #include "util/Destroy.hh"
 #include "util/log/Log.hh"
 #include "xml/Node.hh"
@@ -53,12 +53,11 @@ namespace
 	const std::string state_file = ".grive_state" ;
 }
 
-Drive::Drive( OAuth2& auth, const Json& options ) :
-	m_auth( auth ),
+Drive::Drive( http::Agent *http, const Json& options ) :
+	m_http( http ),
 	m_state( state_file, options )
 {
-	m_http_hdr.Add( "Authorization: Bearer " + m_auth.AccessToken() ) ;
-	m_http_hdr.Add( "GData-Version: 3.0" ) ;
+	assert( m_http != 0 ) ;
 }
 
 void Drive::FromRemote( const Entry& entry )
@@ -93,14 +92,14 @@ void Drive::SaveState()
 	m_state.Write( state_file ) ;
 }
 
-void Drive::SyncFolders( http::Agent *http )
+void Drive::SyncFolders( )
 {
-	assert( http != 0 ) ;
+	assert( m_http != 0 ) ;
 
 	Log( "Synchronizing folders", log::info ) ;
 
 	http::XmlResponse xml ;
-	http->Get( feed_base + "/-/folder?max-results=50&showroot=true", &xml, m_http_hdr ) ;
+	m_http->Get( feed_base + "/-/folder?max-results=50&showroot=true", &xml, http::Header() ) ;
 	
 	Feed feed( xml.Response() ) ;
 	do
@@ -121,7 +120,7 @@ void Drive::SyncFolders( http::Agent *http )
 					m_state.FromRemote( e ) ;
 			}
 		}
-	} while ( feed.GetNext( http, m_http_hdr ) ) ;
+	} while ( feed.GetNext( m_http, http::Header() ) ) ;
 
 	m_state.ResolveEntry() ;
 }
@@ -131,17 +130,15 @@ void Drive::DetectChanges()
 	Log( "Reading local directories", log::info ) ;
 	m_state.FromLocal( "." ) ;
 	
-	http::CurlAgent http ;
-
 	long prev_stamp = m_state.ChangeStamp() ;
 	Trace( "previous change stamp is %1%", prev_stamp ) ;
 	
-	SyncFolders( &http ) ;
+	SyncFolders( ) ;
 
 	Log( "Reading remote server file list", log::info ) ;
 	Feed feed ;
 // 	feed.EnableLog( "/tmp/file", ".xml" ) ;
-	feed.Start( &http, m_http_hdr, feed_base + "?showfolders=true&showroot=true" ) ;
+	feed.Start( m_http, http::Header(), feed_base + "?showfolders=true&showroot=true" ) ;
 	
 	m_resume_link = feed.Root()["link"].
 		Find( "@rel", "http://schemas.google.com/g/2005#resumable-create-media" )["@href"] ;
@@ -152,7 +149,7 @@ void Drive::DetectChanges()
 			feed.begin(), feed.end(),
 			boost::bind( &Drive::FromRemote, this, _1 ) ) ;
 			
-	} while ( feed.GetNext( &http, m_http_hdr ) ) ;
+	} while ( feed.GetNext( m_http, http::Header() ) ) ;
 	
 	// pull the changes feed
 	if ( prev_stamp != -1 )
@@ -160,7 +157,7 @@ void Drive::DetectChanges()
 		Log( "Detecting changes from last sync", log::info ) ;
 		Feed changes ;
 // 		feed.EnableLog( "/tmp/changes", ".xml" ) ;
-		feed.Start( &http, m_http_hdr, ChangesFeed(prev_stamp+1) ) ;
+		feed.Start( m_http, http::Header(), ChangesFeed(prev_stamp+1) ) ;
 		
 		std::for_each(
 			changes.begin(), changes.end(),
@@ -171,25 +168,24 @@ void Drive::DetectChanges()
 void Drive::Update()
 {
 	Log( "Synchronizing files", log::info ) ;
-	http::CurlAgent http ;
-	m_state.Sync( &http, m_http_hdr ) ;
+	m_state.Sync( m_http ) ;
 	
-	UpdateChangeStamp( &http ) ;
+	UpdateChangeStamp( ) ;
 }
 
 void Drive::DryRun()
 {
 	Log( "Synchronizing files (dry-run)", log::info ) ;
-	m_state.Sync( 0, m_http_hdr ) ;
+	m_state.Sync( 0 ) ;
 }
 
-void Drive::UpdateChangeStamp( http::Agent *http )
+void Drive::UpdateChangeStamp( )
 {
-	assert( http != 0 ) ;
+	assert( m_http != 0 ) ;
 
 	// get changed feed
 	http::XmlResponse xrsp ;
-	http->Get( ChangesFeed(m_state.ChangeStamp()+1), &xrsp, m_http_hdr ) ;
+	m_http->Get( ChangesFeed(m_state.ChangeStamp()+1), &xrsp, http::Header() ) ;
 	
 	// we should go through the changes to see if it was really Grive to made that change
 	// maybe by recording the updated timestamp and compare it?
diff --git a/libgrive/src/drive/Drive.hh b/libgrive/src/drive/Drive.hh
index 9a6227c..3641500 100644
--- a/libgrive/src/drive/Drive.hh
+++ b/libgrive/src/drive/Drive.hh
@@ -35,13 +35,12 @@ namespace http
 }
 
 class Entry ;
-class OAuth2 ;
 class Json ;
 
 class Drive
 {
 public :
-	Drive( OAuth2& auth, const Json& options ) ;
+	Drive( http::Agent *http, const Json& options ) ;
 
 	void DetectChanges() ;
 	void Update() ;
@@ -51,15 +50,16 @@ public :
 	struct Error : virtual Exception {} ;
 	
 private :
-	void SyncFolders( http::Agent *http ) ;
+	void SyncFolders( ) ;
     void file();
 	void FromRemote( const Entry& entry ) ;
 	void FromChange( const Entry& entry ) ;
-	void UpdateChangeStamp( http::Agent *http ) ;
+	void UpdateChangeStamp( ) ;
 	
 private :
-	OAuth2&			m_auth ;
-	http::Header	m_http_hdr ;
+	http::Agent 	*m_http ;
+// 	OAuth2&			m_auth ;
+// 	http::Header	m_http_hdr ;
 
 	std::string		m_resume_link ;
 	State			m_state ;
diff --git a/libgrive/src/drive/Resource.cc b/libgrive/src/drive/Resource.cc
index b7e9ffa..268c92f 100644
--- a/libgrive/src/drive/Resource.cc
+++ b/libgrive/src/drive/Resource.cc
@@ -365,20 +365,20 @@ Resource* Resource::FindChild( const std::string& name )
 }
 
 // try to change the state to "sync"
-void Resource::Sync( http::Agent *http, const http::Header& auth, DateTime& sync_time )
+void Resource::Sync( http::Agent *http, DateTime& sync_time )
 {
 	assert( m_state != unknown ) ;
 	assert( !IsRoot() || m_state == sync ) ;	// root folder is already synced
 	
-	SyncSelf( http, auth, sync_time ) ;
+	SyncSelf( http, sync_time ) ;
 	
 	// if myself is deleted, no need to do the childrens
 	if ( m_state != local_deleted && m_state != remote_deleted )
 		std::for_each( m_child.begin(), m_child.end(),
-			boost::bind( &Resource::Sync, _1, http, auth, boost::ref(sync_time) ) ) ;
+			boost::bind( &Resource::Sync, _1, http, boost::ref(sync_time) ) ) ;
 }
 
-void Resource::SyncSelf( http::Agent* http, const http::Header& auth, DateTime& sync_time )
+void Resource::SyncSelf( http::Agent* http, DateTime& sync_time )
 {
 	assert( !IsRoot() || m_state == sync ) ;	// root is always sync
 	assert( IsRoot() || http == 0 || fs::is_directory( m_parent->Path() ) ) ;
@@ -392,19 +392,19 @@ void Resource::SyncSelf( http::Agent* http, const http::Header& auth, DateTime&
 	case local_new :
 		Log( "sync %1% doesn't exist in server, uploading", path, log::info ) ;
 		
-		if ( http != 0 && Create( http, auth, sync_time ) )
+		if ( http != 0 && Create( http, sync_time ) )
 			m_state = sync ;
 		break ;
 	
 	case local_deleted :
 		Log( "sync %1% deleted in local. deleting remote", path, log::info ) ;
 		if ( http != 0 )
-			DeleteRemote( http, auth ) ;
+			DeleteRemote( http ) ;
 		break ;
 	
 	case local_changed :
 		Log( "sync %1% changed in local. uploading", path, log::info ) ;
-		if ( http != 0 && EditContent( http, auth, sync_time ) )
+		if ( http != 0 && EditContent( http, sync_time ) )
 			m_state = sync ;
 		break ;
 	
@@ -415,7 +415,7 @@ void Resource::SyncSelf( http::Agent* http, const http::Header& auth, DateTime&
 			if ( IsFolder() )
 				fs::create_directories( path ) ;
 			else
-				Download( http, path, auth ) ;
+				Download( http, path ) ;
 			
 			m_state = sync ;
 		}
@@ -426,7 +426,7 @@ void Resource::SyncSelf( http::Agent* http, const http::Header& auth, DateTime&
 		Log( "sync %1% changed in remote. downloading", path, log::info ) ;
 		if ( http != 0 )
 		{
-			Download( http, path, auth ) ;
+			Download( http, path ) ;
 			m_state = sync ;
 		}
 		break ;
@@ -474,14 +474,14 @@ void Resource::DeleteLocal()
 	}
 }
 
-void Resource::DeleteRemote( http::Agent *http, const http::Header& auth )
+void Resource::DeleteRemote( http::Agent *http )
 {
 	assert( http != 0 ) ;
 	http::StringResponse str ;
 	
 	try
 	{
-		http::Header hdr( auth ) ;
+		http::Header hdr ;
 		hdr.Add( "If-Match: " + m_etag ) ;
 		
 		// doesn't know why, but an update before deleting seems to work always
@@ -502,12 +502,12 @@ void Resource::DeleteRemote( http::Agent *http, const http::Header& auth )
 }
 
 
-void Resource::Download( http::Agent* http, const fs::path& file, const http::Header& auth ) const
+void Resource::Download( http::Agent* http, const fs::path& file ) const
 {
 	assert( http != 0 ) ;
 	
 	http::Download dl( file.string(), http::Download::NoChecksum() ) ;
-	long r = http->Get( m_content, &dl, auth ) ;
+	long r = http->Get( m_content, &dl, http::Header() ) ;
 	if ( r <= 400 )
 	{
 		if ( m_mtime != DateTime() )
@@ -517,7 +517,7 @@ void Resource::Download( http::Agent* http, const fs::path& file, const http::He
 	}
 }
 
-bool Resource::EditContent( http::Agent* http, const http::Header& auth, DateTime& sync_time )
+bool Resource::EditContent( http::Agent* http, DateTime& sync_time )
 {
 	assert( http != 0 ) ;
 	assert( m_parent != 0 ) ;
@@ -530,10 +530,10 @@ bool Resource::EditContent( http::Agent* http, const http::Header& auth, DateTim
 		return false ;
 	}
 	
-	return Upload( http, m_edit, auth, false, sync_time ) ;
+	return Upload( http, m_edit, false, sync_time ) ;
 }
 
-bool Resource::Create( http::Agent* http, const http::Header& auth, DateTime& sync_time )
+bool Resource::Create( http::Agent* http, DateTime& sync_time )
 {
 	assert( http != 0 ) ;
 	assert( m_parent != 0 ) ;
@@ -551,7 +551,7 @@ bool Resource::Create( http::Agent* http, const http::Header& auth, DateTime& sy
 			% xml::Escape(m_name)
 		).str() ;
 
-		http::Header hdr( auth ) ;
+		http::Header hdr ;
 		hdr.Add( "Content-Type: application/atom+xml" ) ;
 		
 		http::XmlResponse xml ;
@@ -563,7 +563,7 @@ bool Resource::Create( http::Agent* http, const http::Header& auth, DateTime& sy
 	}
 	else if ( !m_parent->m_create.empty() )
 	{
-		return Upload( http, m_parent->m_create + "?convert=false", auth, true, sync_time ) ;
+		return Upload( http, m_parent->m_create + "?convert=false", true, sync_time ) ;
 	}
 	else
 	{
@@ -575,7 +575,6 @@ bool Resource::Create( http::Agent* http, const http::Header& auth, DateTime& sy
 bool Resource::Upload(
 	http::Agent* 		http,
 	const std::string&	link,
-	const http::Header&	auth,
 	bool 				post,
 	DateTime& 			sync_time )
 {
@@ -585,7 +584,7 @@ bool Resource::Upload(
 	std::ostringstream xcontent_len ;
 	xcontent_len << "X-Upload-Content-Length: " << file.Size() ;
 	
-	http::Header hdr( auth ) ;
+	http::Header hdr ;
 	hdr.Add( "Content-Type: application/atom+xml" ) ;
 	hdr.Add( "X-Upload-Content-Type: application/octet-stream" ) ;
 	hdr.Add( xcontent_len.str() ) ;
diff --git a/libgrive/src/drive/Resource.hh b/libgrive/src/drive/Resource.hh
index 8a76017..75efdc4 100644
--- a/libgrive/src/drive/Resource.hh
+++ b/libgrive/src/drive/Resource.hh
@@ -32,7 +32,6 @@ namespace gr {
 namespace http
 {
 	class Agent ;
-	class Header ;
 }
 
 class Entry ;
@@ -77,7 +76,7 @@ public :
 	void FromRemote( const Entry& remote, const DateTime& last_sync ) ;
 	void FromLocal( const DateTime& last_sync ) ;
 	
-	void Sync( http::Agent* http, const http::Header& auth, DateTime& sync_time ) ;
+	void Sync( http::Agent* http, DateTime& sync_time ) ;
 
 	// children access
 	iterator begin() const ;
@@ -124,19 +123,19 @@ private :
 private :
 	void SetState( State new_state ) ;
 
-	void Download( http::Agent* http, const fs::path& file, const http::Header& auth ) const ;
-	bool EditContent( http::Agent* http, const http::Header& auth, DateTime& sync_time ) ;
-	bool Create( http::Agent* http, const http::Header& auth, DateTime& sync_time ) ;
-	bool Upload( http::Agent* http, const std::string& link, const http::Header& auth, bool post, DateTime& sync_time ) ;
+	void Download( http::Agent* http, const fs::path& file ) const ;
+	bool EditContent( http::Agent* http, DateTime& sync_time ) ;
+	bool Create( http::Agent* http, DateTime& sync_time ) ;
+	bool Upload( http::Agent* http, const std::string& link, bool post, DateTime& sync_time ) ;
 	
 	void FromRemoteFolder( const Entry& remote, const DateTime& last_sync ) ;
 	void FromRemoteFile( const Entry& remote, const DateTime& last_sync ) ;
 	
 	void DeleteLocal() ;
-	void DeleteRemote( http::Agent* http, const http::Header& auth ) ;
+	void DeleteRemote( http::Agent* http ) ;
 	
 	void AssignIDs( const Entry& remote ) ;
-	void SyncSelf( http::Agent* http, const http::Header& auth, DateTime& sync_time ) ;
+	void SyncSelf( http::Agent* http, DateTime& sync_time ) ;
 	
 private :
 	std::string				m_name ;
diff --git a/libgrive/src/drive/State.cc b/libgrive/src/drive/State.cc
index f024818..afab842 100644
--- a/libgrive/src/drive/State.cc
+++ b/libgrive/src/drive/State.cc
@@ -24,7 +24,6 @@
 #include "CommonUri.hh"
 
 #include "http/Agent.hh"
-#include "http/Header.hh"
 #include "util/Crypt.hh"
 #include "util/log/Log.hh"
 #include "protocol/Json.hh"
@@ -262,7 +261,7 @@ void State::Write( const fs::path& filename ) const
 	fs << result ;
 }
 
-void State::Sync( http::Agent *http, const http::Header& auth )
+void State::Sync( http::Agent *http )
 {
 	// set the last sync time from the time returned by the server for the last file synced
 	// if the sync time hasn't changed (i.e. now files have been uploaded)
@@ -272,7 +271,7 @@ void State::Sync( http::Agent *http, const http::Header& auth )
 	// TODO - WARNING - do we use the last sync time to compare to client file times
 	// need to check if this introduces a new problem
  	DateTime last_sync_time = m_last_sync;
-	m_res.Root()->Sync( http, auth, last_sync_time ) ;
+	m_res.Root()->Sync( http, last_sync_time ) ;
   	if ( last_sync_time == m_last_sync )
   	{
 		Trace( "nothing changed? %1%", m_last_sync ) ;
diff --git a/libgrive/src/drive/State.hh b/libgrive/src/drive/State.hh
index 563abe5..cd0590d 100644
--- a/libgrive/src/drive/State.hh
+++ b/libgrive/src/drive/State.hh
@@ -31,7 +31,6 @@ namespace gr {
 namespace http
 {
 	class Agent ;
-	class Header ;
 }
 
 class Json ;
@@ -58,7 +57,7 @@ public :
 	Resource* FindByID( const std::string& id ) ;
 	Resource* Find( const fs::path& path ) ;
 
-	void Sync( http::Agent *http, const http::Header& auth ) ;
+	void Sync( http::Agent *http ) ;
 	
 	iterator begin() ;
 	iterator end() ;
diff --git a/libgrive/src/http/Header.cc b/libgrive/src/http/Header.cc
index 36bd245..9f0bdd3 100644
--- a/libgrive/src/http/Header.cc
+++ b/libgrive/src/http/Header.cc
@@ -50,4 +50,11 @@ std::ostream& operator<<( std::ostream& os, const Header& h )
 	return os ;
 }
 
+Header operator+( const Header& header, const std::string& str )
+{
+	Header h( header ) ;
+	h.Add( str ) ;
+	return h ;
+}
+
 } } // end of namespace
diff --git a/libgrive/src/http/Header.hh b/libgrive/src/http/Header.hh
index c581d7d..2486cd0 100644
--- a/libgrive/src/http/Header.hh
+++ b/libgrive/src/http/Header.hh
@@ -46,5 +46,6 @@ private :
 } ;
 
 std::ostream& operator<<( std::ostream& os, const Header& h ) ;
+Header operator+( const Header& header, const std::string& str ) ;
 
 }} // end of namespace
diff --git a/libgrive/src/protocol/AuthAgent.cc b/libgrive/src/protocol/AuthAgent.cc
new file mode 100644
index 0000000..06cacd2
--- /dev/null
+++ b/libgrive/src/protocol/AuthAgent.cc
@@ -0,0 +1,103 @@
+/*
+	grive: an GPL program to sync a local directory with Google Drive
+	Copyright (C) 2012  Wan Wai Ho
+
+	This program 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 version 2
+	of the License.
+
+	This program 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 this program; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#include "AuthAgent.hh"
+#include "http/Header.hh"
+
+#include <cassert>
+
+namespace gr {
+
+using namespace http ;
+
+AuthAgent::AuthAgent( const OAuth2& auth, std::auto_ptr<Agent> real_agent ) :
+	m_auth	( auth ),
+	m_agent	( real_agent )
+{
+	assert( m_agent.get() != 0 ) ;
+}
+
+Header AuthAgent::AppendHeader( const Header& hdr ) const
+{
+	Header h(hdr) ;
+	h.Add( "Authorization: Bearer " + m_auth.AccessToken() ) ;
+	h.Add( "GData-Version: 3.0" ) ;
+	return h ;
+}
+
+long AuthAgent::Put(
+	const std::string&	url,
+	const std::string&	data,
+	Receivable			*dest,
+	const Header&		hdr )
+{
+	return m_agent->Put( url, data, dest, AppendHeader(hdr) ) ;
+}
+
+long AuthAgent::Put(
+	const std::string&	url,
+	StdioFile&			file,
+	Receivable			*dest,
+	const Header&		hdr )
+{
+	return m_agent->Put( url, file, dest, AppendHeader(hdr) ) ;
+}
+
+long AuthAgent::Get(
+	const std::string& 	url,
+	Receivable			*dest,
+	const Header&		hdr )
+{
+	return m_agent->Get( url, dest, AppendHeader(hdr) ) ;
+}
+
+long AuthAgent::Post(
+	const std::string& 	url,
+	const std::string&	data,
+	Receivable			*dest,
+	const Header&		hdr )
+{
+	return m_agent->Post( url, data, dest, AppendHeader(hdr) ) ;
+}
+
+long AuthAgent::Custom(
+	const std::string&	method,
+	const std::string&	url,
+	Receivable			*dest,
+	const Header&		hdr )
+{
+	return m_agent->Custom( method, url, dest, AppendHeader(hdr) ) ;
+}
+
+std::string AuthAgent::RedirLocation() const
+{
+	return m_agent->RedirLocation() ;
+}
+
+std::string AuthAgent::Escape( const std::string& str )
+{
+	return m_agent->Escape( str ) ;
+}
+
+std::string AuthAgent::Unescape( const std::string& str )
+{
+	return m_agent->Unescape( str ) ;
+}
+
+} // end of namespace
diff --git a/libgrive/src/protocol/AuthAgent.hh b/libgrive/src/protocol/AuthAgent.hh
new file mode 100644
index 0000000..d3fb053
--- /dev/null
+++ b/libgrive/src/protocol/AuthAgent.hh
@@ -0,0 +1,81 @@
+/*
+	grive: an GPL program to sync a local directory with Google Drive
+	Copyright (C) 2012  Wan Wai Ho
+
+	This program 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 version 2
+	of the License.
+
+	This program 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 this program; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#pragma once
+
+#include "http/Agent.hh"
+#include "OAuth2.hh"
+
+#include <memory>
+
+namespace gr {
+
+/*!	\brief	An HTTP agent with support OAuth2
+	
+	This is a HTTP agent that provide support for OAuth2. It will also perform retries on
+	certain HTTP errors.
+*/
+class AuthAgent : public http::Agent
+{
+public :
+	AuthAgent( const OAuth2& auth, std::auto_ptr<http::Agent> real_agent ) ;
+
+	long Put(
+		const std::string&	url,
+		const std::string&	data,
+		http::Receivable	*dest,
+		const http::Header&	hdr ) ;
+	
+	long Put(
+		const std::string&	url,
+		StdioFile&			file,
+		http::Receivable	*dest,
+		const http::Header&	hdr ) ;
+
+	long Get(
+		const std::string& 	url,
+		http::Receivable	*dest,
+		const http::Header&	hdr ) ;
+	
+	long Post(
+		const std::string& 	url,
+		const std::string&	data,
+		http::Receivable	*dest,
+		const http::Header&	hdr ) ;
+	
+	long Custom(
+		const std::string&	method,
+		const std::string&	url,
+		http::Receivable	*dest,
+		const http::Header&	hdr ) ;
+	
+	std::string RedirLocation() const ;
+	
+	std::string Escape( const std::string& str ) ;
+	std::string Unescape( const std::string& str ) ;
+
+private :
+	http::Header AppendHeader( const http::Header& hdr ) const ;
+	
+private :
+	OAuth2								m_auth ;
+	const std::auto_ptr<http::Agent>	m_agent ;
+} ;
+
+} // end of namespace