diff --git a/libethereum/ExtVMFace.h b/libethereum/ExtVMFace.h
new file mode 100644
index 000000000..a70261ee0
--- /dev/null
+++ b/libethereum/ExtVMFace.h
@@ -0,0 +1,69 @@
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum 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.
+
+	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/** @file ExtVMFace.h
+ * @author Gav Wood <i@gavwood.com>
+ * @date 2014
+ */
+
+#pragma once
+
+#include "Common.h"
+#include "FeeStructure.h"
+#include "BlockInfo.h"
+
+namespace eth
+{
+
+class Transaction;
+
+class ExtVMFace
+{
+public:
+	ExtVMFace(Address _myAddress, Address _txSender, u256 _txValue, u256s const& _txData, FeeStructure const& _fees, BlockInfo const& _previousBlock, BlockInfo const& _currentBlock, uint _currentNumber):
+		myAddress(_myAddress),
+		txSender(_txSender),
+		txValue(_txValue),
+		txData(_txData),
+		fees(_fees),
+		previousBlock(_previousBlock),
+		currentBlock(_currentBlock),
+		currentNumber(_currentNumber)
+	{}
+
+	u256 store(u256 _n) { return 0; }
+	void setStore(u256 _n, u256 _v) {}
+	u256 temp(u256 _n) { return 0; }
+	void setTemp(u256 _n, u256 _v) {}
+	void mktx(Transaction& _t) {}
+	u256 balance(Address _a) { return 0; }
+	void payFee(bigint _fee) {}
+	u256 txCount(Address _a) { return 0; }
+	u256 extro(Address _a, u256 _pos) { return 0; }
+	u256 extroPrice(Address _a) { return 0; }
+	void suicide(Address _a) {}
+
+	Address myAddress;
+	Address txSender;
+	u256 txValue;
+	u256s const& txData;
+	FeeStructure fees;
+	BlockInfo previousBlock;					///< The current block's information.
+	BlockInfo currentBlock;					///< The current block's information.
+	uint currentNumber;
+};
+
+}