diff --git a/libethereum/Client.cpp b/libethereum/Client.cpp
index c62fe42de..c5bdf4c1a 100644
--- a/libethereum/Client.cpp
+++ b/libethereum/Client.cpp
@@ -25,6 +25,7 @@
 #include <thread>
 #include <boost/filesystem.hpp>
 #include <libethential/Log.h>
+#include <libethnet/PeerHost.h>
 #include "Defaults.h"
 #include "EthereumHost.h"
 using namespace std;
@@ -213,7 +214,9 @@ void Client::startNetwork(unsigned short _listenPort, std::string const& _seedHo
 
 			try
 			{
-				m_net.reset(new EthereumHost(m_clientVersion, m_bc, _networkId, _listenPort, _mode, _publicIP, _upnp));
+				m_net.reset(new PeerHost(m_clientVersion, _listenPort, _publicIP, _upnp));
+				if (_mode == NodeMode::Full)
+					m_net->registerCapability(new EthereumHost(m_bc, _networkId));
 			}
 			catch (std::exception const&)
 			{
diff --git a/libethereum/Client.h b/libethereum/Client.h
index 9499b0d4c..2848bd85a 100644
--- a/libethereum/Client.h
+++ b/libethereum/Client.h
@@ -28,9 +28,10 @@
 #include <boost/utility.hpp>
 #include <libethential/Common.h>
 #include <libethential/CommonIO.h>
+#include <libethential/Guards.h>
 #include <libevm/FeeStructure.h>
 #include <libethcore/Dagger.h>
-#include <libethential/Guards.h>
+#include <libethnet/Common.h>
 #include "BlockChain.h"
 #include "TransactionQueue.h"
 #include "State.h"
@@ -51,6 +52,12 @@ enum ClientWorkState
 	Deleted
 };
 
+enum class NodeMode
+{
+	Peer,
+	Full
+};
+
 class VersionChecker
 {
 public:
diff --git a/libethereum/CommonNet.h b/libethereum/CommonNet.h
index 0b848e2c3..1ab4ab2d3 100644
--- a/libethereum/CommonNet.h
+++ b/libethereum/CommonNet.h
@@ -41,9 +41,9 @@ class OverlayDB;
 class BlockChain;
 class TransactionQueue;
 class EthereumHost;
-class EthereumSession;
+class EthereumPeer;
 
-enum PacketType
+enum
 {
 	StatusPacket = 0x10,
 	GetTransactionsPacket,
diff --git a/libethereum/EthereumHost.cpp b/libethereum/EthereumHost.cpp
index d5d8e08cd..836f3f8f0 100644
--- a/libethereum/EthereumHost.cpp
+++ b/libethereum/EthereumHost.cpp
@@ -28,26 +28,27 @@
 #include <thread>
 #include <libethential/Common.h>
 #include <libethnet/PeerHost.h>
+#include <libethnet/PeerSession.h>
 #include <libethcore/UPnP.h>
 #include <libethcore/Exceptions.h>
 #include "BlockChain.h"
 #include "TransactionQueue.h"
 #include "BlockQueue.h"
-#include "EthereumSession.h"
+#include "EthereumPeer.h"
 using namespace std;
 using namespace eth;
 
 EthereumHost::EthereumHost(BlockChain const& _ch, u256 _networkId):
-	m_chain(&_ch),
-	m_networkId(_networkId)
+	HostCapability<EthereumPeer>(),
+	m_chain		(&_ch),
+	m_networkId	(_networkId)
 {
 }
 
 EthereumHost::~EthereumHost()
 {
-	for (auto i: host()->m_peers)
-		if (shared_ptr<EthereumSession> p = i.second.lock())
-			p->giveUpOnFetch();
+	for (auto const& i: peers())
+		i->cap<EthereumPeer>()->giveUpOnFetch();
 }
 
 h256Set EthereumHost::neededBlocks(h256Set const& _exclude)
@@ -84,7 +85,6 @@ bool EthereumHost::ensureInitialised(TransactionQueue& _tq)
 
 		for (auto const& i: _tq.transactions())
 			m_transactionsSent.insert(i.first);
-		m_lastPeersRequest = chrono::steady_clock::time_point::min();
 		return true;
 	}
 	return false;
@@ -135,31 +135,30 @@ void EthereumHost::maintainTransactions(TransactionQueue& _tq, h256 _currentHash
 	m_incomingTransactions.clear();
 
 	// Send any new transactions.
-	Guard l(host()->x_peers);
-	for (auto j: host()->m_peers)
-		if (auto p = j.second.lock())
-		{
-			bytes b;
-			uint n = 0;
-			for (auto const& i: _tq.transactions())
-				if ((!m_transactionsSent.count(i.first) && !p->m_knownTransactions.count(i.first)) || p->m_requireTransactions || resendAll)
-				{
-					b += i.second;
-					++n;
-					m_transactionsSent.insert(i.first);
-				}
-			if (n)
+	for (auto const& p: peers())
+	{
+		auto ep = p->cap<EthereumPeer>();
+		bytes b;
+		uint n = 0;
+		for (auto const& i: _tq.transactions())
+			if ((!m_transactionsSent.count(i.first) && !ep->m_knownTransactions.count(i.first)) || ep->m_requireTransactions || resendAll)
 			{
-				RLPStream ts;
-				EthereumSession::prep(ts);
-				ts.appendList(n + 1) << TransactionsPacket;
-				ts.appendRaw(b, n).swapOut(b);
-				seal(b);
-				p->send(&b);
+				b += i.second;
+				++n;
+				m_transactionsSent.insert(i.first);
 			}
-			p->m_knownTransactions.clear();
-			p->m_requireTransactions = false;
+		if (n)
+		{
+			RLPStream ts;
+			EthereumPeer::prep(ts);
+			ts.appendList(n + 1) << TransactionsPacket;
+			ts.appendRaw(b, n).swapOut(b);
+			seal(b);
+			ep->send(&b);
 		}
+		ep->m_knownTransactions.clear();
+		ep->m_requireTransactions = false;
+	}
 }
 
 void EthereumHost::maintainBlocks(BlockQueue& _bq, h256 _currentHash)
@@ -184,7 +183,7 @@ void EthereumHost::maintainBlocks(BlockQueue& _bq, h256 _currentHash)
 	if (m_latestBlockSent != _currentHash)
 	{
 		RLPStream ts;
-		EthereumSession::prep(ts);
+		EthereumPeer::prep(ts);
 		bytes bs;
 		unsigned c = 0;
 		for (auto h: m_chain->treeRoute(m_latestBlockSent, _currentHash, nullptr, false, true))
@@ -198,19 +197,18 @@ void EthereumHost::maintainBlocks(BlockQueue& _bq, h256 _currentHash)
 		ts.swapOut(b);
 		seal(b);
 
-		Guard l(host()->x_peers);
-		for (auto j: host()->m_peers)
-			if (auto p = j.second.lock())
-			{
-				if (!p->m_knownBlocks.count(_currentHash))
-					p->send(&b);
-				p->m_knownBlocks.clear();
-			}
+		for (auto j: peers())
+		{
+			auto p = j->cap<EthereumPeer>();
+			if (!p->m_knownBlocks.count(_currentHash))
+				p->send(&b);
+			p->m_knownBlocks.clear();
+		}
 		m_latestBlockSent = _currentHash;
 	}
 }
 
-void EthereumHost::noteHaveChain(std::shared_ptr<EthereumSession> const& _from)
+void EthereumHost::noteHaveChain(EthereumPeer* _from)
 {
 	auto td = _from->m_totalDifficulty;
 
@@ -235,10 +233,6 @@ void EthereumHost::noteHaveChain(std::shared_ptr<EthereumSession> const& _from)
 		m_totalDifficultyOfNeeded = td;
 	}
 
-	{
-		Guard l(host()->x_peers);
-		for (auto const& i: host()->m_peers)
-			if (shared_ptr<EthereumSession> p = i.second.lock())
-				p->restartGettingChain();
-	}
+	for (auto j: peers())
+		j->cap<EthereumPeer>()->restartGettingChain();
 }
diff --git a/libethereum/EthereumHost.h b/libethereum/EthereumHost.h
index f172ea508..d2c28644b 100644
--- a/libethereum/EthereumHost.h
+++ b/libethereum/EthereumHost.h
@@ -32,13 +32,14 @@
 #include <libethcore/CommonEth.h>
 #include <libethnet/Common.h>
 #include "CommonNet.h"
-#include "EthereumSession.h"
+#include "EthereumPeer.h"
 
 namespace eth
 {
 
 class RLPStream;
 class TransactionQueue;
+class BlockQueue;
 
 /**
  * @brief The EthereumHost class
@@ -66,7 +67,7 @@ private:
 	/// @returns true if we didn't have it.
 	bool noteBlock(h256 _hash, bytesConstRef _data);
 	/// Session has finished getting the chain of hashes.
-	void noteHaveChain(std::shared_ptr<EthereumSession> const& _who);
+	void noteHaveChain(EthereumPeer* _who);
 	/// Called when the peer can no longer provide us with any needed blocks.
 	void noteDoneBlocks();
 
diff --git a/libethereum/EthereumSession.cpp b/libethereum/EthereumPeer.cpp
similarity index 76%
rename from libethereum/EthereumSession.cpp
rename to libethereum/EthereumPeer.cpp
index 579aa5354..72de75e35 100644
--- a/libethereum/EthereumSession.cpp
+++ b/libethereum/EthereumPeer.cpp
@@ -14,24 +14,25 @@
 	You should have received a copy of the GNU General Public License
 	along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
 */
-/** @file EthereumSession.cpp
+/** @file EthereumPeer.cpp
  * @author Gav Wood <i@gavwood.com>
  * @date 2014
  */
 
-#include "EthereumSession.h"
+#include "EthereumPeer.h"
 
 #include <chrono>
 #include <libethential/Common.h>
 #include <libethcore/Exceptions.h>
+#include <libethnet/PeerSession.h>
 #include "BlockChain.h"
 #include "EthereumHost.h"
 using namespace std;
 using namespace eth;
 
-#define clogS(X) eth::LogOutputStream<X, true>(false) << "| " << std::setw(2) << m_socket.native_handle() << "] "
+#define clogS(X) eth::LogOutputStream<X, true>(false) << "| " << std::setw(2) << session()->id() << "] "
 
-EthereumPeer::EthereumPeer(PeerSession* _s, HostCapability* _h): PeerCapability(_s, _h)
+EthereumPeer::EthereumPeer(PeerSession* _s, HostCapabilityFace* _h): PeerCapability(_s, _h)
 {
 	sendStatus();
 }
@@ -41,16 +42,21 @@ EthereumPeer::~EthereumPeer()
 	giveUpOnFetch();
 }
 
+EthereumHost* EthereumPeer::host() const
+{
+	return static_cast<EthereumHost*>(PeerCapability::hostCapability());
+}
+
 void EthereumPeer::sendStatus()
 {
 	RLPStream s;
-	m_session->prep(s);
+	prep(s);
 	s.appendList(9) << StatusPacket
-					<< hostCapability()->protocolVersion()
-					<< hostCapability()->networkId()
-					<< hostCapability()->m_chain->details().totalDifficulty
-					<< hostCapability()->m_chain->currentHash()
-					<< hostCapability()->m_chain->genesisHash();
+					<< host()->protocolVersion()
+					<< host()->networkId()
+					<< host()->m_chain->details().totalDifficulty
+					<< host()->m_chain->currentHash()
+					<< host()->m_chain->genesisHash();
 	sealAndSend(s);
 }
 
@@ -64,11 +70,11 @@ void EthereumPeer::startInitialSync()
 		sealAndSend(s);
 	}
 
-	h256 c = m_server->m_chain->currentHash();
-	uint n = m_server->m_chain->number();
-	u256 td = max(m_server->m_chain->details().totalDifficulty, m_server->m_totalDifficultyOfNeeded);
+	h256 c = host()->m_chain->currentHash();
+	uint n = host()->m_chain->number();
+	u256 td = max(host()->m_chain->details().totalDifficulty, host()->m_totalDifficultyOfNeeded);
 
-	clogS(NetAllDetail) << "Initial sync. Latest:" << c.abridged() << ", number:" << n << ", TD: max(" << m_server->m_chain->details().totalDifficulty << "," << m_server->m_totalDifficultyOfNeeded << ") versus " << m_totalDifficulty;
+	clogS(NetAllDetail) << "Initial sync. Latest:" << c.abridged() << ", number:" << n << ", TD: max(" << host()->m_chain->details().totalDifficulty << "," << host()->m_totalDifficultyOfNeeded << ") versus " << m_totalDifficulty;
 	if (td > m_totalDifficulty)
 		return;	// All good - we have the better chain.
 
@@ -97,13 +103,13 @@ void EthereumPeer::giveUpOnFetch()
 	clogS(NetNote) << "GIVE UP FETCH; can't get " << toString(m_askedBlocks);
 	if (m_askedBlocks.size())
 	{
-		Guard l (m_server->x_blocksNeeded);
-		m_server->m_blocksNeeded.reserve(m_server->m_blocksNeeded.size() + m_askedBlocks.size());
+		Guard l (host()->x_blocksNeeded);
+		host()->m_blocksNeeded.reserve(host()->m_blocksNeeded.size() + m_askedBlocks.size());
 		for (auto i: m_askedBlocks)
 		{
 			m_failedBlocks.insert(i);
-			m_server->m_blocksOnWay.erase(i);
-			m_server->m_blocksNeeded.push_back(i);
+			host()->m_blocksOnWay.erase(i);
+			host()->m_blocksNeeded.push_back(i);
 		}
 		m_askedBlocks.clear();
 	}
@@ -123,11 +129,11 @@ bool EthereumPeer::interpret(RLP const& _r)
 
 		clogS(NetMessageSummary) << "Status: " << m_protocolVersion << "/" << m_networkId << "/" << genesisHash.abridged() << ", TD:" << m_totalDifficulty << "=" << m_latestHash.abridged();
 
-		if (genesisHash != hostCapability()->m_chain->genesisHash())
+		if (genesisHash != host()->m_chain->genesisHash())
 			disable("Invalid genesis hash");
-		if (m_protocolVersion != hostCapability()->protocolVersion())
+		if (m_protocolVersion != host()->protocolVersion())
 			disable("Invalid protocol version.");
-		if (m_networkId != hostCapability()->networkId() || !m_id)
+		if (m_networkId != host()->networkId())
 			disable("Invalid network identifier.");
 
 		startInitialSync();
@@ -140,10 +146,10 @@ bool EthereumPeer::interpret(RLP const& _r)
 	}
 	case TransactionsPacket:
 		clogS(NetMessageSummary) << "Transactions (" << dec << (_r.itemCount() - 1) << " entries)";
-		m_rating += _r.itemCount() - 1;
+		addRating(_r.itemCount() - 1);
 		for (unsigned i = 1; i < _r.itemCount(); ++i)
 		{
-			m_server->m_incomingTransactions.push_back(_r[i].data().toBytes());
+			host()->m_incomingTransactions.push_back(_r[i].data().toBytes());
 			m_knownTransactions.insert(sha3(_r[i].data()));
 		}
 		break;
@@ -153,12 +159,12 @@ bool EthereumPeer::interpret(RLP const& _r)
 		unsigned limit = _r[2].toInt<unsigned>();
 		clogS(NetMessageSummary) << "GetBlockHashes (" << limit << "entries, " << later.abridged() << ")";
 
-		unsigned c = min<unsigned>(m_server->m_chain->number(later), limit);
+		unsigned c = min<unsigned>(host()->m_chain->number(later), limit);
 
 		RLPStream s;
 		prep(s).appendList(1 + c).append(BlockHashesPacket);
-		h256 p = m_server->m_chain->details(later).parent;
-		for (unsigned i = 0; i < c; ++i, p = m_server->m_chain->details(p).parent)
+		h256 p = host()->m_chain->details(later).parent;
+		for (unsigned i = 0; i < c; ++i, p = host()->m_chain->details(p).parent)
 			s << p;
 		sealAndSend(s);
 		break;
@@ -168,15 +174,15 @@ bool EthereumPeer::interpret(RLP const& _r)
 		clogS(NetMessageSummary) << "BlockHashes (" << dec << (_r.itemCount() - 1) << " entries)";
 		if (_r.itemCount() == 1)
 		{
-			m_server->noteHaveChain(shared_from_this());
+			host()->noteHaveChain(this);
 			return true;
 		}
 		for (unsigned i = 1; i < _r.itemCount(); ++i)
 		{
 			auto h = _r[i].toHash<h256>();
-			if (m_server->m_chain->details(h))
+			if (host()->m_chain->details(h))
 			{
-				m_server->noteHaveChain(shared_from_this());
+				host()->noteHaveChain(this);
 				return true;
 			}
 			else
@@ -197,7 +203,7 @@ bool EthereumPeer::interpret(RLP const& _r)
 		unsigned n = 0;
 		for (unsigned i = 1; i < _r.itemCount() && i <= c_maxBlocks; ++i)
 		{
-			auto b = m_server->m_chain->block(_r[i].toHash<h256>());
+			auto b = host()->m_chain->block(_r[i].toHash<h256>());
 			if (b.size())
 			{
 				rlp += b;
@@ -223,12 +229,12 @@ bool EthereumPeer::interpret(RLP const& _r)
 		for (unsigned i = 1; i < _r.itemCount(); ++i)
 		{
 			auto h = BlockInfo::headerHash(_r[i].data());
-			if (m_server->noteBlock(h, _r[i].data()))
+			if (host()->noteBlock(h, _r[i].data()))
 				used++;
 			m_askedBlocks.erase(h);
 			m_knownBlocks.insert(h);
 		}
-		m_rating += used;
+		addRating(used);
 		unsigned knownParents = 0;
 		unsigned unknownParents = 0;
 		if (g_logVerbosity >= NetMessageSummary::verbosity)
@@ -237,7 +243,7 @@ bool EthereumPeer::interpret(RLP const& _r)
 			{
 				auto h = BlockInfo::headerHash(_r[i].data());
 				BlockInfo bi(_r[i].data());
-				if (!m_server->m_chain->details(bi.parentHash) && !m_knownBlocks.count(bi.parentHash))
+				if (!host()->m_chain->details(bi.parentHash) && !m_knownBlocks.count(bi.parentHash))
 				{
 					unknownParents++;
 					clogS(NetAllDetail) << "Unknown parent " << bi.parentHash << " of block " << h;
@@ -282,7 +288,7 @@ void EthereumPeer::ensureGettingChain()
 void EthereumPeer::continueGettingChain()
 {
 	if (!m_askedBlocks.size())
-		m_askedBlocks = m_server->neededBlocks(m_failedBlocks);
+		m_askedBlocks = host()->neededBlocks(m_failedBlocks);
 
 	if (m_askedBlocks.size())
 	{
@@ -296,6 +302,6 @@ void EthereumPeer::continueGettingChain()
 	else
 	{
 		clogS(NetMessageSummary) << "No blocks left to get. Peer doesn't seem to have " << m_failedBlocks.size() << "of our needed blocks.";
-		m_server->noteDoneBlocks();
+		host()->noteDoneBlocks();
 	}
 }
diff --git a/libethereum/EthereumSession.h b/libethereum/EthereumPeer.h
similarity index 86%
rename from libethereum/EthereumSession.h
rename to libethereum/EthereumPeer.h
index 1b10c71fe..3b182b450 100644
--- a/libethereum/EthereumSession.h
+++ b/libethereum/EthereumPeer.h
@@ -14,7 +14,7 @@
 	You should have received a copy of the GNU General Public License
 	along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
 */
-/** @file EthereumSession.h
+/** @file EthereumPeer.h
  * @author Gav Wood <i@gavwood.com>
  * @date 2014
  */
@@ -28,13 +28,15 @@
 #include <utility>
 #include <libethential/RLP.h>
 #include <libethcore/CommonEth.h>
+#include <libethnet/Common.h>
 #include "CommonNet.h"
-#include "EthereumHost.h"
 
 namespace eth
 {
 
-class WhisperSession: public PeerSession
+class HostCapabilityFace;
+
+class WhisperSession: public PeerCapability
 {
 public:
 	WhisperSession();
@@ -43,11 +45,11 @@ public:
 	static std::string name() { return "shh"; }
 
 private:
-	virtual bool interpret(RLP const&) {}
+	virtual bool interpret(RLP const&) { return false; }
 };
 
 /**
- * @brief The EthereumSession class
+ * @brief The EthereumPeer class
  * @todo Document fully.
  */
 class EthereumPeer: public PeerCapability
@@ -55,12 +57,12 @@ class EthereumPeer: public PeerCapability
 	friend class EthereumHost;
 
 public:
-	EthereumPeer(PeerSession* _s, HostCapability* _h);
+	EthereumPeer(PeerSession* _s, HostCapabilityFace* _h);
 	virtual ~EthereumPeer();
 
 	static std::string name() { return "eth"; }
 
-	EthereumHost* hostCapability() const { return static_cast<EthereumHost*>(PeerCapability::hostCapability()); }
+	EthereumHost* host() const;
 
 private:
 	virtual bool interpret(RLP const& _r);
@@ -77,8 +79,6 @@ private:
 
 	void giveUpOnFetch();
 
-	EthereumHost* m_host;
-
 	uint m_protocolVersion;
 	u256 m_networkId;
 
diff --git a/libethereumx/Ethereum.cpp b/libethereumx/Ethereum.cpp
index a7725abb5..c4cc29d87 100644
--- a/libethereumx/Ethereum.cpp
+++ b/libethereumx/Ethereum.cpp
@@ -38,11 +38,11 @@ void Ethereum::ensureReady()
 		{
 			m_client = unique_ptr<Client>(new Client("+ethereum+"));
 			if (m_client)
-				startServer();
+				startRPCServer();
 		}
 		catch (DatabaseAlreadyOpen)
 		{
-			startClient();
+			connectToRPCServer();
 		}
 }
 
@@ -55,11 +55,11 @@ bool Ethereum::connectionOpen() const
 	return false;
 }
 
-void Ethereum::startClient()
+void Ethereum::connectToRPCServer()
 {
 }
 
-void Ethereum::startServer()
+void Ethereum::startRPCServer()
 {
 }
 
diff --git a/libethereumx/Ethereum.h b/libethereumx/Ethereum.h
index fb272c030..0966fd699 100644
--- a/libethereumx/Ethereum.h
+++ b/libethereumx/Ethereum.h
@@ -132,9 +132,9 @@ private:
 	/// Check to see if the client/server connection is open.
 	bool connectionOpen() const;
 	/// Start the API client.
-	void startClient();
+	void connectToRPCServer();
 	/// Start the API server.
-	void startServer();
+	void startRPCServer();
 
 	std::unique_ptr<Client> m_client;
 
diff --git a/libethnet/Common.cpp b/libethnet/Common.cpp
index 6224f93ca..f0f0e4d2d 100644
--- a/libethnet/Common.cpp
+++ b/libethnet/Common.cpp
@@ -20,6 +20,10 @@
  */
 
 #include "Common.h"
+
+#include <libethential/RLP.h>
+#include "PeerSession.h"
+#include "PeerHost.h"
 using namespace std;
 using namespace eth;
 
@@ -61,6 +65,47 @@ std::string eth::reasonOf(DisconnectReason _r)
 
 void PeerCapability::disable(std::string const& _problem)
 {
-	clogS(NetConnect) << "Disabling capability '" << m_host->name() << "'. Reason:" << _problem;
+	clog(NetConnect) << "Disabling capability '" << m_host->name() << "'. Reason:" << _problem;
 	m_enabled = false;
 }
+
+void HostCapabilityFace::seal(bytes& _b)
+{
+	m_host->seal(_b);
+}
+
+std::vector<std::shared_ptr<PeerSession> > HostCapabilityFace::peers() const
+{
+	Guard l(m_host->x_peers);
+	std::vector<std::shared_ptr<PeerSession> > ret;
+	for (auto const& i: m_host->m_peers)
+		if (std::shared_ptr<PeerSession> p = i.second.lock())
+			if (p->m_capabilities.count(name()))
+				ret.push_back(p);
+	return ret;
+}
+
+RLPStream& PeerCapability::prep(RLPStream& _s)
+{
+	return PeerSession::prep(_s);
+}
+
+void PeerCapability::sealAndSend(RLPStream& _s)
+{
+	m_session->sealAndSend(_s);
+}
+
+void PeerCapability::sendDestroy(bytes& _msg)
+{
+	m_session->sendDestroy(_msg);
+}
+
+void PeerCapability::send(bytesConstRef _msg)
+{
+	m_session->send(_msg);
+}
+
+void PeerCapability::addRating(unsigned _r)
+{
+	m_session->addRating(_r);
+}
diff --git a/libethnet/Common.h b/libethnet/Common.h
index c70e42aaa..ccc066e88 100644
--- a/libethnet/Common.h
+++ b/libethnet/Common.h
@@ -38,6 +38,7 @@ namespace eth
 bool isPrivateAddress(bi::address _addressToCheck);
 
 class RLP;
+class RLPStream;
 class PeerHost;
 class PeerSession;
 
@@ -72,6 +73,7 @@ enum DisconnectReason
 	TooManyPeers,
 	DuplicatePeer,
 	IncompatibleProtocol,
+	InvalidIdentity,
 	ClientQuit,
 	UserReason = 0x10
 };
@@ -94,35 +96,41 @@ class PeerCapability;
 class HostCapabilityFace
 {
 	friend class PeerHost;
+	template <class T> friend class HostCapability;
+	friend class PeerCapability;
 
 public:
-	HostCapabilityFace(PeerHost*) {}
+	HostCapabilityFace() {}
 	virtual ~HostCapabilityFace() {}
 
+	PeerHost* host() const { return m_host; }
+
+	std::vector<std::shared_ptr<PeerSession> > peers() const;
+
 protected:
 	virtual std::string name() const = 0;
 	virtual PeerCapability* newPeerCapability(PeerSession* _s) = 0;
 	virtual bool isInitialised() const = 0;
+
+	void seal(bytes& _b);
+
+private:
+	PeerHost* m_host = nullptr;
 };
 
 template<class PeerCap>
 class HostCapability: public HostCapabilityFace
 {
 public:
-	HostCapability(PeerHost* _h): m_host(_h) {}
+	HostCapability() {}
 	virtual ~HostCapability() {}
 
 	static std::string staticName() { return PeerCap::name(); }
 
-	PeerHost* host() const { return m_host; }
-
 protected:
 	virtual bool isInitialised() const = 0;
 	virtual std::string name() const { return PeerCap::name(); }
 	virtual PeerCapability* newPeerCapability(PeerSession* _s) { return new PeerCap(_s, this); }
-
-private:
-	PeerHost* m_host;
 };
 
 class PeerCapability
@@ -130,23 +138,30 @@ class PeerCapability
 	friend class PeerSession;
 
 public:
-	PeerCapability(PeerSession* _s, HostCapability* _h): m_session(_s), m_host(_h) {}
+	PeerCapability(PeerSession* _s, HostCapabilityFace* _h): m_session(_s), m_host(_h) {}
 	virtual ~PeerCapability() {}
 
 	/// Must return the capability name.
 	static std::string name() { return ""; }
 
 	PeerSession* session() const { return m_session; }
-	HostCapability* hostCapability() const { return m_host; }
+	HostCapabilityFace* hostCapability() const { return m_host; }
 
 protected:
 	virtual bool interpret(RLP const&) = 0;
 
 	void disable(std::string const& _problem);
 
+	static RLPStream& prep(RLPStream& _s);
+	void sealAndSend(RLPStream& _s);
+	void sendDestroy(bytes& _msg);
+	void send(bytesConstRef _msg);
+
+	void addRating(unsigned _r);
+
 private:
 	PeerSession* m_session;
-	HostCapability* m_host;
+	HostCapabilityFace* m_host;
 	bool m_enabled = true;
 };
 
diff --git a/libethnet/PeerHost.cpp b/libethnet/PeerHost.cpp
index b5627719f..1206eb0bf 100644
--- a/libethnet/PeerHost.cpp
+++ b/libethnet/PeerHost.cpp
@@ -62,6 +62,7 @@ PeerHost::PeerHost(std::string const& _clientVersion, unsigned short _port, stri
 	populateAddresses();
 	determinePublic(_publicAddress, _upnp);
 	ensureAccepting();
+	m_lastPeersRequest = chrono::steady_clock::time_point::min();
 	clog(NetNote) << "Id:" << toHex(m_key.address().ref().cropped(0, 4));
 }
 
@@ -78,6 +79,7 @@ PeerHost::PeerHost(std::string const& _clientVersion, string const& _publicAddre
 	populateAddresses();
 	determinePublic(_publicAddress, _upnp);
 	ensureAccepting();
+	m_lastPeersRequest = chrono::steady_clock::time_point::min();
 	clog(NetNote) << "Id:" << toHex(m_key.address().ref().cropped(0, 4));
 }
 
@@ -90,6 +92,7 @@ PeerHost::PeerHost(std::string const& _clientVersion):
 {
 	// populate addresses.
 	populateAddresses();
+	m_lastPeersRequest = chrono::steady_clock::time_point::min();
 	clog(NetNote) << "Id:" << toHex(m_key.address().ref().cropped(0, 4));
 }
 
@@ -103,15 +106,15 @@ unsigned PeerHost::protocolVersion() const
 	return 0;
 }
 
-void PeerHost::registerPeer(std::shared_ptr<PeerSession> _s)
+void PeerHost::registerPeer(std::shared_ptr<PeerSession> _s, vector<string> const& _caps)
 {
 	{
 		Guard l(x_peers);
 		m_peers[_s->m_id] = _s;
 	}
-	for (auto const& i: _s->m_caps)
+	for (auto const& i: _caps)
 		if (haveCapability(i))
-			_s->m_capabilities.push_back(shared_ptr<PeerCapability>(m_capabilities[i]->newPeerCapability(_s.get())));
+			_s->m_capabilities[i] = shared_ptr<PeerCapability>(m_capabilities[i]->newPeerCapability(_s.get()));
 }
 
 void PeerHost::disconnectPeers()
@@ -453,8 +456,8 @@ std::vector<PeerInfo> PeerHost::peers(bool _updatePing) const
 void PeerHost::process()
 {
 	for (auto const& i: m_capabilities)
-		if (!i->isInitialised())
-			return false;
+		if (!i.second->isInitialised())
+			return;
 	growPeers();
 	prunePeers();
 	m_ioService.poll();
diff --git a/libethnet/PeerHost.h b/libethnet/PeerHost.h
index 00c5beb88..d56b512c7 100644
--- a/libethnet/PeerHost.h
+++ b/libethnet/PeerHost.h
@@ -48,6 +48,7 @@ class BlockQueue;
 class PeerHost
 {
 	friend class PeerSession;
+	friend class HostCapabilityFace;
 
 public:
 	/// Start server, listening for connections on the given port.
@@ -67,7 +68,7 @@ public:
 	unsigned protocolVersion() const;
 
 	/// Register a peer-capability; all new peer connections will have this capability.
-	template <class T> void registerCapability() { m_capabilities[T::name()] = std::shared_ptr<HostCapabilityFace>(new T(this)); }
+	template <class T> void registerCapability(T* _t) { _t->m_host = this; m_capabilities[T::name()] = std::shared_ptr<HostCapabilityFace>(_t); }
 
 	/// Connect to a peer explicitly.
 	void connect(std::string const& _addr, unsigned short _port = 30303) noexcept;
@@ -102,7 +103,7 @@ public:
 	/// Deserialise the data and populate the set of known peers.
 	void restorePeers(bytesConstRef _b);
 
-	void registerPeer(std::shared_ptr<PeerSession> _s);
+	void registerPeer(std::shared_ptr<PeerSession> _s, std::vector<std::string> const& _caps);
 
 	bool haveCapability(std::string const& _name) const { return m_capabilities.count(_name); }
 	std::vector<std::string> caps() const { std::vector<std::string> ret; for (auto const& i: m_capabilities) ret.push_back(i.first); return ret; }
diff --git a/libethnet/PeerSession.cpp b/libethnet/PeerSession.cpp
index dfa5d6195..d69100047 100644
--- a/libethnet/PeerSession.cpp
+++ b/libethnet/PeerSession.cpp
@@ -45,7 +45,7 @@ PeerSession::~PeerSession()
 {
 	// Read-chain finished for one reason or another.
 	for (auto& i: m_capabilities)
-		i.reset();
+		i.second.reset();
 
 	try
 	{
@@ -76,11 +76,11 @@ bool PeerSession::interpret(RLP const& _r)
 	{
 		m_protocolVersion = _r[1].toInt<uint>();
 		auto clientVersion = _r[2].toString();
-		m_caps = _r[3].toVector<string>();
+		auto caps = _r[3].toVector<string>();
 		m_listenPort = _r[4].toInt<unsigned short>();
 		m_id = _r[5].toHash<h512>();
 
-		clogS(NetMessageSummary) << "Hello: " << clientVersion << "V[" << m_protocolVersion << "]" << m_id.abridged() << showbase << hex << m_caps << dec << m_listenPort;
+		clogS(NetMessageSummary) << "Hello: " << clientVersion << "V[" << m_protocolVersion << "]" << m_id.abridged() << showbase << hex << caps << dec << m_listenPort;
 
 		if (m_server->havePeer(m_id))
 		{
@@ -89,8 +89,12 @@ bool PeerSession::interpret(RLP const& _r)
 			disconnect(DuplicatePeer);
 			return false;
 		}
-
-		if (m_protocolVersion != m_server->protocolVersion() || !m_id)
+		if (!m_id)
+		{
+			disconnect(InvalidIdentity);
+			return false;
+		}
+		if (m_protocolVersion != m_server->protocolVersion())
 		{
 			disconnect(IncompatibleProtocol);
 			return false;
@@ -103,7 +107,7 @@ bool PeerSession::interpret(RLP const& _r)
 			return false;
 		}
 
-		m_server->registerPeer(shared_from_this());
+		m_server->registerPeer(shared_from_this(), caps);
 		break;
 	}
 	case DisconnectPacket:
@@ -180,7 +184,7 @@ bool PeerSession::interpret(RLP const& _r)
 		break;
 	default:
 		for (auto const& i: m_capabilities)
-			if (i->m_enabled && i->interpret(_r))
+			if (i.second->m_enabled && i.second->interpret(_r))
 				return true;
 		return false;
 	}
diff --git a/libethnet/PeerSession.h b/libethnet/PeerSession.h
index 5919bf11d..13ab6bb90 100644
--- a/libethnet/PeerSession.h
+++ b/libethnet/PeerSession.h
@@ -40,6 +40,7 @@ namespace eth
 class PeerSession: public std::enable_shared_from_this<PeerSession>
 {
 	friend class PeerHost;
+	friend class HostCapabilityFace;
 
 public:
 	PeerSession(PeerHost* _server, bi::tcp::socket _socket, bi::address _peerAddress, unsigned short _peerPort = 0);
@@ -52,13 +53,20 @@ public:
 
 	bool isOpen() const { return m_socket.is_open(); }
 
+	unsigned id() const { return m_socket.native_handle(); }
+
 	bi::tcp::endpoint endpoint() const;	///< for other peers to connect to.
 
+	template <class PeerCap>
+	PeerCap* cap() const { try { return static_cast<PeerCap*>(m_capabilities.at(PeerCap::name())); } catch (...) { return nullptr; } }
+
 	static RLPStream& prep(RLPStream& _s);
 	void sealAndSend(RLPStream& _s);
 	void sendDestroy(bytes& _msg);
 	void send(bytesConstRef _msg);
 
+	void addRating(unsigned _r) { m_rating += _r; }
+
 private:
 	void dropped();
 	void doRead();
@@ -77,7 +85,7 @@ private:
 	std::recursive_mutex m_writeLock;
 	std::deque<bytes> m_writeQueue;
 
-	bi::tcp::socket m_socket;
+	mutable bi::tcp::socket m_socket;	///< Mutable to ask for native_handle().
 	std::array<byte, 65536> m_data;
 	PeerInfo m_info;
 	Public m_id;
@@ -85,7 +93,6 @@ private:
 	bytes m_incoming;
 	uint m_protocolVersion;
 	unsigned short m_listenPort;			///< Port that the remote client is listening on for connections. Useful for giving to peers.
-	std::vector<std::string> m_caps;
 
 	std::chrono::steady_clock::time_point m_ping;
 	std::chrono::steady_clock::time_point m_connect;
@@ -93,7 +100,7 @@ private:
 
 	uint m_rating;
 
-	std::vector<std::shared_ptr<PeerCapability>> m_capabilities;
+	std::map<std::string, std::shared_ptr<PeerCapability>> m_capabilities;
 
 	bool m_willBeDeleted = false;			///< True if we already posted a deleter on the strand.
 };