diff --git a/libgrive/src/drive2/Drive.cc b/libgrive/src/drive2/Drive.cc
index cb3fad6..feaa84b 100644
--- a/libgrive/src/drive2/Drive.cc
+++ b/libgrive/src/drive2/Drive.cc
@@ -22,9 +22,12 @@
 
 #include "CommonUri.hh"
 #include "Feed.hh"
-#include "protocol/Json.hh"
+#include "json/Val.hh"
 #include "util/Exception.hh"
 
+#include <boost/bind.hpp>
+
+#include <algorithm>
 #include <iostream>
 #include <iterator>
 
@@ -74,8 +77,8 @@ void Drive::NewResource( http::Agent *agent, Feed& items )
 	
 	while ( items.Next( agent ) )
 	{
-		std::vector<Json> item_json = items.Content()["items"].AsArray() ;
-		for ( std::vector<Json>::iterator i = item_json.begin() ; i != item_json.end() ; ++i )
+		std::vector<Val> item_json = items.Content()["items"].AsArray() ;
+		for ( std::vector<Val>::iterator i = item_json.begin() ; i != item_json.end() ; ++i )
 			NewResource( *i ) ;
 	}
 }
@@ -89,16 +92,19 @@ Resource* Drive::NewResource( http::Agent *agent, const std::string& id )
 	return NewResource( feed.Content() ) ;
 }
 
-Resource* Drive::NewResource( const Json& item )
+Resource* Drive::NewResource( const Val& item )
 {
 	// assume resource is directly under root
 	std::string parent_id = m_root != 0 ? m_root->ID() : "" ;
 	
-	Json parents ;
+	Val parents ;
 	if ( item.Get( "parents", parents ) )
 	{
+		std::vector<Val> pids_val = parents.Select( "id" ) ;
 		std::vector<std::string> pids ;
-		parents.Select<std::string>( "id", std::back_inserter(pids) ) ;
+		std::transform( pids_val.begin(), pids_val.end(),
+			std::back_inserter( pids ),
+			boost::bind( &Val::Str, _1 ) ) ;
 
 		// only the first parent counts
 		if ( !pids.empty() )
diff --git a/libgrive/src/drive2/Drive.hh b/libgrive/src/drive2/Drive.hh
index 392fb62..33014b0 100644
--- a/libgrive/src/drive2/Drive.hh
+++ b/libgrive/src/drive2/Drive.hh
@@ -34,7 +34,7 @@ namespace http
 	class Agent ;
 }
 
-class Json ;
+class Val ;
 
 namespace v2 {
 
@@ -76,7 +76,7 @@ public :
 	const Resource* Parent( const Resource *child ) const ;
 
 private :
-	Resource* NewResource( const Json& item ) ;
+	Resource* NewResource( const Val& item ) ;
 	Resource* NewResource( http::Agent *agent, const std::string& id ) ;
 	void NewResource( http::Agent *agent, Feed& items ) ;
 	
diff --git a/libgrive/src/drive2/Feed.cc b/libgrive/src/drive2/Feed.cc
index 952d3a7..78f67f0 100644
--- a/libgrive/src/drive2/Feed.cc
+++ b/libgrive/src/drive2/Feed.cc
@@ -21,7 +21,7 @@
 
 #include "http/Agent.hh"
 #include "http/Header.hh"
-#include "protocol/JsonResponse.hh"
+#include "json/ValResponse.hh"
 
 #include <iostream>
 
@@ -31,22 +31,22 @@ Feed::Feed( const std::string& base ) :
 	m_base( base )
 {
 	// Next() will grab this link
-	m_content.Add( "nextLink", Json(base) ) ;
+	m_content.Add( "nextLink", Val(base) ) ;
 }
 
 void Feed::Query( const std::string& field, const std::string& value )
 {
 	std::string url = m_content["nextLink"].Str() ;
-	m_content.Add( "nextLink", Json( url + "?q=" + field + "+%3d+%27" + value + "%27" ) ) ;
+	m_content.Add( "nextLink", Val( url + "?q=" + field + "+%3d+%27" + value + "%27" ) ) ;
 }
 
 bool Feed::Next( http::Agent *agent )
 {
-	Json url ;
+	Val url ;
 	if ( !m_content.Get("nextLink", url) )
 		return false ;
 	
-	http::JsonResponse out ;
+	http::ValResponse out ;
 	try
 	{
 		agent->Get( url.Str(), &out, http::Header() ) ;
@@ -61,7 +61,7 @@ bool Feed::Next( http::Agent *agent )
 	return true ;
 }
 
-Json Feed::Content() const
+Val Feed::Content() const
 {
 	return m_content ;
 }
diff --git a/libgrive/src/drive2/Feed.hh b/libgrive/src/drive2/Feed.hh
index bbdd92b..ad1f294 100644
--- a/libgrive/src/drive2/Feed.hh
+++ b/libgrive/src/drive2/Feed.hh
@@ -19,7 +19,7 @@
 
 #pragma once
 
-#include "protocol/Json.hh"
+#include "json/Val.hh"
 #include "util/Exception.hh"
 
 #include <string>
@@ -32,7 +32,7 @@ namespace http
 	class Header ;
 }
 
-class Json ;
+class Val ;
 
 namespace v2 {
 
@@ -40,7 +40,7 @@ class Feed
 {
 public :
 	// exception info
-	typedef boost::error_info<struct DriveFeed,	Json>	DriveFeed_ ;
+	typedef boost::error_info<struct DriveFeed,	Val>	DriveFeed_ ;
 
 public :
 	Feed( const std::string& base ) ;
@@ -49,11 +49,11 @@ public :
 	
 	bool Next( http::Agent *agent ) ;
 
-	Json Content() const ;
+	Val Content() const ;
 
 private :
 	std::string	m_base ;
-	Json 		m_content ;
+	Val 		m_content ;
 } ;
 
 } } // end of namespace gr::v2
diff --git a/libgrive/src/json/Val.cc b/libgrive/src/json/Val.cc
index 02f7dff..79c0b5e 100644
--- a/libgrive/src/json/Val.cc
+++ b/libgrive/src/json/Val.cc
@@ -27,9 +27,30 @@
 
 namespace gr {
 
-Val::Val( ) :
-	m_base( new Impl<void> )
+const Val& Val::Null()
 {
+	static const Val null( null_type ) ;
+	return null ;
+}
+
+Val::Val( ) :
+	m_base( new Impl<Object> )
+{
+}
+
+Val::Val( TypeEnum type )
+{
+	switch ( type )
+	{
+		case int_type:		m_base.reset( new Impl<long long> ) ;	break ;
+		case bool_type:		m_base.reset( new Impl<bool> ) ; 		break ;
+		case double_type:	m_base.reset( new Impl<double> ) ; 		break ;
+		case string_type:	m_base.reset( new Impl<std::string> ) ;	break ;
+		case array_type:	m_base.reset( new Impl<Array> ) ; break ;
+		case object_type:	m_base.reset( new Impl<Object> ) ; break ;
+		case null_type:	
+		default:			m_base.reset( new Impl<void> ) ; break ;
+	}
 }
 
 Val::Val( const Val& v ) :
@@ -174,6 +195,35 @@ void Val::Visit( ValVisitor *visitor ) const
 	}
 }
 
+void Val::Select( const Object& obj, const std::string& key, std::vector<Val>& result ) const
+{
+	Object::const_iterator i = obj.find(key) ;
+	if ( i != obj.end() )
+		result.push_back(i->second) ;
+}
+
+/**	If \a this is an array of objects, this function returns all values of
+	the objects in the array with the key \a key. If \a this is an object,
+	just return the value with the key \a key. 
+*/
+std::vector<Val> Val::Select( const std::string& key ) const
+{
+	std::vector<Val> result ;
+	if ( Is<Object>() )
+		Select( As<Object>(), key, result ) ;
+	
+	else if ( Is<Array>() )
+	{
+		const Array& array = As<Array>() ;
+		for ( Array::const_iterator i = array.begin() ; i != array.end() ; ++i )
+		{
+			if ( i->Is<Object>() )
+				Select( i->As<Object>(), key, result ) ;
+		}
+	}
+	return result ;
+}
+
 std::ostream& operator<<( std::ostream& os, const Val& val )
 {
 	StdStream ss( os.rdbuf() ) ;
diff --git a/libgrive/src/json/Val.hh b/libgrive/src/json/Val.hh
index 56e43bc..2547886 100644
--- a/libgrive/src/json/Val.hh
+++ b/libgrive/src/json/Val.hh
@@ -58,8 +58,11 @@ public :
 public :
 	Val() ;
 	Val( const Val& v ) ;
+	explicit Val( TypeEnum type ) ;
 	~Val() ;
 
+	static const Val& Null() ;
+
 	template <typename T>
 	explicit Val( const T& t )
 	{
@@ -110,19 +113,22 @@ public :
 	void Add( const Val& json ) ;
 	Val  FindInArray( const std::string& key, const std::string& value ) const ;
 	bool FindInArray( const std::string& key, const std::string& value, Val& result ) const ;
-		
+	
+	std::vector<Val> Select( const std::string& key ) const ;
+	
 	friend std::ostream& operator<<( std::ostream& os, const Val& val ) ;
 	void Visit( ValVisitor *visitor ) const ;
 
 private :
 	struct Base ;
-	
+
 	template <typename T>
 	struct Impl ;
 	
 	std::auto_ptr<Base>	m_base ;
 
 private :
+	void Select( const Object& obj, const std::string& key, std::vector<Val>& result ) const ;
 } ;
 
 template <> struct Val::Type2Enum<void>			{ static const TypeEnum type = null_type ; } ;
@@ -160,6 +166,7 @@ template <typename T>
 struct Val::Impl : public Base
 {
 	T val ;
+	Impl( ) : val() {}
 	Impl( const T& t ) : val(t) {}
 	Impl<T>* Clone() const { return new Impl<T>(val); }
 	TypeEnum Type() const { return Type2Enum<T>::type ; }
diff --git a/libgrive/src/json/ValBuilder.cc b/libgrive/src/json/ValBuilder.cc
index a80be2d..c5658ff 100644
--- a/libgrive/src/json/ValBuilder.cc
+++ b/libgrive/src/json/ValBuilder.cc
@@ -60,37 +60,41 @@ void ValBuilder::VisitNull()
 void ValBuilder::Build( const Val& t )
 {
 	if ( m_ctx.empty() )
-		m_ctx.push( t ) ;
-	
-	else if ( m_ctx.top().Is<Val::Array>() )
 	{
-		Val::Array& ar = m_ctx.top().As<Val::Array>() ;
+		Level l = { Val::Null(), t } ;
+		m_ctx.push( l ) ;
+	}
+	
+	else if ( m_ctx.top().val.Is<Val::Array>() )
+	{
+		Val::Array& ar = m_ctx.top().val.As<Val::Array>() ;
 		ar.push_back( t ) ;
 	}
-	else if ( m_ctx.top().Is<Val::Object>() )
+	else if ( m_ctx.top().val.Is<Val::Object>() )
 	{
-		if ( m_key.get() == 0 )
+		if ( !m_ctx.top().key.Is<std::string>() )
 			BOOST_THROW_EXCEPTION( Error() << NoKey_(t) ) ;
 	
 		else
 		{
-			Val::Object& obj = m_ctx.top().As<Val::Object>() ;
-			obj.insert( std::make_pair( m_key->As<std::string>(), t ) ) ;
-			m_key.reset() ;
+			Val::Object& obj = m_ctx.top().val.As<Val::Object>() ;
+			obj.insert( std::make_pair( m_ctx.top().key.Str(), t ) ) ;
+			m_ctx.top().key = Val::Null() ;
 		}
 	}
 	else
-		BOOST_THROW_EXCEPTION( Error() << Unexpected_(m_ctx.top()) ) ;
+		BOOST_THROW_EXCEPTION( Error() << Unexpected_(m_ctx.top().val) ) ;
 }
 
 void ValBuilder::VisitKey( const std::string& t )
 {
-	m_key.reset( new Val(t) ) ;
+	m_ctx.top().key = t ;
 }
 
 void ValBuilder::StartArray()
 {
-	m_ctx.push( Val( Val::Array() ) ) ;
+	Level l = { Val::Null(), Val(Val::Array()) } ;
+	m_ctx.push(l) ;
 }
 
 void ValBuilder::EndArray()
@@ -100,11 +104,13 @@ void ValBuilder::EndArray()
 
 void ValBuilder::End( Val::TypeEnum type )
 {
-	if ( m_ctx.top().Type() == type )
+	if ( m_ctx.top().val.Type() == type )
 	{
+		assert( m_ctx.top().key.Is<void>() ) ;
+	
 		// get top Val from stack
 		Val current ;
-		current.Swap( m_ctx.top() ) ;
+		current.Swap( m_ctx.top().val ) ;
 		m_ctx.pop() ;
 		
 		Build(current) ;
@@ -113,7 +119,8 @@ void ValBuilder::End( Val::TypeEnum type )
 
 void ValBuilder::StartObject()
 {
-	m_ctx.push( Val( Val::Object() ) ) ;
+	Level l = { Val::Null(), Val( Val::Object() ) } ;
+	m_ctx.push(l) ;
 }
 
 void ValBuilder::EndObject()
@@ -124,7 +131,7 @@ void ValBuilder::EndObject()
 Val ValBuilder::Result() const
 {
 	assert( m_ctx.size() == 1U ) ;
-	return m_ctx.top() ;
+	return m_ctx.top().val ;
 }
 
 } // end of namespace
diff --git a/libgrive/src/json/ValBuilder.hh b/libgrive/src/json/ValBuilder.hh
index f5c2ab3..efbe5b2 100644
--- a/libgrive/src/json/ValBuilder.hh
+++ b/libgrive/src/json/ValBuilder.hh
@@ -61,8 +61,13 @@ private :
 	void End( Val::TypeEnum type ) ;
 
 private :
-	std::stack<Val> 	m_ctx ;
-	std::auto_ptr<Val>	m_key ;
+	struct Level
+	{
+		Val	key ;
+		Val	val ;
+	} ;
+
+	std::stack<Level> 	m_ctx ;
 } ;
 
 } // end of namespace