diff --git a/bzz/bzzcontract/bzzcontract_test.go b/bzz/bzzcontract/bzzcontract_test.go
new file mode 100644
index 0000000000..6ea4452e9c
--- /dev/null
+++ b/bzz/bzzcontract/bzzcontract_test.go
@@ -0,0 +1,191 @@
+package bzzcontract
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io/ioutil"
+	"math/big"
+	"os"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	//"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/rpc"
+	xe "github.com/ethereum/go-ethereum/xeth"
+)
+
+type testFrontend struct {
+	t        *testing.T
+	ethereum *eth.Ethereum
+	xeth     *xe.XEth
+	api      *rpc.EthereumApi
+	coinbase string
+}
+
+func (f *testFrontend) UnlockAccount(acc []byte) bool {
+	f.t.Logf("Unlocking account %v\n", common.Bytes2Hex(acc))
+	f.ethereum.AccountManager().Unlock(acc, "password")
+	return true
+}
+
+func (f *testFrontend) ConfirmTransaction(tx *types.Transaction) bool {
+	return true
+}
+
+var port = 30300
+
+func testEth(t *testing.T) (ethereum *eth.Ethereum, err error) {
+	os.RemoveAll("/tmp/eth/")
+	err = os.MkdirAll("/tmp/eth/keys/e273f01c99144c438695e10f24926dc1f9fbf62d/", os.ModePerm)
+	if err != nil {
+		t.Errorf("%v", err)
+		return
+	}
+	err = os.MkdirAll("/tmp/eth/data", os.ModePerm)
+	if err != nil {
+		t.Errorf("%v", err)
+		return
+	}
+	ks := crypto.NewKeyStorePlain("/tmp/eth/keys")
+	ioutil.WriteFile("/tmp/eth/keys/e273f01c99144c438695e10f24926dc1f9fbf62d/e273f01c99144c438695e10f24926dc1f9fbf62d",
+		[]byte(`{"Id":"RhRXD+fNRKS4jx+7ZfEsNA==","Address":"4nPwHJkUTEOGleEPJJJtwfn79i0=","PrivateKey":"h4ACVpe74uIvi5Cg/2tX/Yrm2xdr3J7QoMbMtNX2CNc="}`), os.ModePerm)
+
+	port++
+	ethereum, err = eth.New(&eth.Config{
+		DataDir:        "/tmp/eth",
+		AccountManager: accounts.NewManager(ks),
+		Port:           fmt.Sprintf("%d", port),
+		MaxPeers:       10,
+		Name:           "test",
+	})
+
+	if err != nil {
+		t.Errorf("%v", err)
+		return
+	}
+
+	return
+}
+
+func testInit(t *testing.T) (self *testFrontend) {
+
+	ethereum, err := testEth(t)
+	if err != nil {
+		t.Errorf("error creating jsre, got %v", err)
+		return
+	}
+	err = ethereum.Start()
+	if err != nil {
+		t.Errorf("error starting ethereum: %v", err)
+		return
+	}
+
+	self = &testFrontend{t: t, ethereum: ethereum}
+	self.xeth = xe.New(ethereum, self)
+	self.api = rpc.NewEthereumApi(self.xeth)
+
+	addr := self.xeth.Coinbase()
+	self.coinbase = addr
+	if addr != "0x"+core.TestAccount {
+		t.Errorf("CoinBase %v does not match TestAccount 0x%v", addr, core.TestAccount)
+	}
+	t.Logf("CoinBase is %v", addr)
+
+	balance := self.xeth.BalanceAt(core.TestAccount)
+	t.Logf("Balance is %v", balance)
+
+	return
+
+}
+
+func (self *testFrontend) insertTx(addr, contract, fnsig string, args []string) {
+
+	//cb := common.HexToAddress(self.coinbase)
+	//coinbase := self.ethereum.ChainManager().State().GetStateObject(cb)
+
+	hash := common.Bytes2Hex(crypto.Sha3([]byte(fnsig)))
+	data := "0x" + hash[0:8]
+	for _, arg := range args {
+		data = data + common.Bytes2Hex(common.Hex2BytesFixed(arg, 32))
+	}
+	self.t.Logf("Tx data: %v", data)
+
+	jsontx := `
+[{
+	  "from": "` + addr + `",
+      "to": "0x` + contract + `",
+	  "value": "100000000000",
+	  "gas": "100000",
+	  "gasPrice": "100000",
+      "data": "` + data + `"
+}]
+`
+	req := &rpc.RpcRequest{
+		Jsonrpc: "2.0",
+		Method:  "eth_transact",
+		Params:  []byte(jsontx),
+		Id:      6,
+	}
+
+	var reply interface{}
+	err0 := self.api.GetRequestReply(req, &reply)
+	if err0 != nil {
+		self.t.Errorf("GetRequestReply error: %v", err0)
+	}
+
+	//self.xeth.Transact(addr, contract, "100000000000", "100000", "100000", data)
+}
+
+func (self *testFrontend) applyTxs() {
+
+	cb := common.HexToAddress(self.coinbase)
+	stateDb := self.ethereum.ChainManager().State().Copy()
+	block := self.ethereum.ChainManager().NewBlock(cb)
+	coinbase := stateDb.GetStateObject(cb)
+	coinbase.SetGasPool(big.NewInt(1000000))
+	txs := self.ethereum.TxPool().GetTransactions()
+
+	for i := 0; i < len(txs); i++ {
+		for _, tx := range txs {
+			if tx.Nonce() == uint64(i) {
+				_, gas, err := core.ApplyMessage(core.NewEnv(stateDb, self.ethereum.ChainManager(), tx, block), tx, coinbase)
+				//self.ethereum.TxPool().RemoveSet([]*types.Transaction{tx})
+				self.t.Logf("ApplyMessage: gas %v  err %v", gas, err)
+			}
+		}
+	}
+
+	self.ethereum.TxPool().RemoveSet(txs)
+	self.xeth = self.xeth.WithState(stateDb)
+
+}
+
+func storageAddress(varidx uint32, key []byte) string {
+	data := make([]byte, 64)
+	binary.BigEndian.PutUint32(data[60:64], varidx)
+	copy(data[0:32], key[0:32])
+	return "0x" + common.Bytes2Hex(crypto.Sha3(data))
+}
+
+func TestSwarmContract(t *testing.T) {
+
+	tf := testInit(t)
+	defer tf.ethereum.Stop()
+
+	tf.insertTx(tf.coinbase, core.ContractAddrSwarm, "signup(uint256)", []string{"1000"})
+	tf.applyTxs()
+
+	addr := common.Hex2BytesFixed(tf.coinbase[2:], 32)
+	key := storageAddress(0, addr)
+	data := tf.xeth.StorageAt("0x"+core.ContractAddrSwarm, key)
+	key = key[:65] + "6"
+	data2 := tf.xeth.StorageAt("0x"+core.ContractAddrSwarm, key)
+
+	t.Logf("addr = %x  key = %v  data = %v, %v", addr, key, data, data2)
+
+}
diff --git a/common/bytes.go b/common/bytes.go
index 5bdacd810a..5d1245107a 100644
--- a/common/bytes.go
+++ b/common/bytes.go
@@ -147,6 +147,23 @@ func Hex2Bytes(str string) []byte {
 	return h
 }
 
+func Hex2BytesFixed(str string, flen int) []byte {
+
+	h, _ := hex.DecodeString(str)
+	if len(h) == flen {
+		return h
+	} else {
+		if len(h) > flen {
+			return h[len(h)-flen : len(h)]
+		} else {
+			hh := make([]byte, flen)
+			copy(hh[flen-len(h):flen], h[:])
+			return hh
+		}
+	}
+
+}
+
 func StringToByteFunc(str string, cb func(str string) []byte) (ret []byte) {
 	if len(str) > 1 && str[0:2] == "0x" && !strings.Contains(str, "\n") {
 		ret = Hex2Bytes(str[2:])
diff --git a/core/contracts.go b/core/contracts.go
index cc07ae7e01..027e9d5019 100644
--- a/core/contracts.go
+++ b/core/contracts.go
@@ -38,7 +38,8 @@ const ( // built-in contracts address and code
 	*/
 
 	ContractAddrSwarm = "000000000000000000000000000000000000000a"
-	ContractCodeSwarm = "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"
+	ContractCodeSwarm = "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"
+	//"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"
 	// see bzz/bzzcontract/swarm.sol
 
 	BuiltInContracts = `
diff --git a/xeth/xeth.go b/xeth/xeth.go
index 825f26017c..14d07978f8 100644
--- a/xeth/xeth.go
+++ b/xeth/xeth.go
@@ -145,10 +145,10 @@ func (self *XEth) AtStateNum(num int64) *XEth {
 		st = self.backend.ChainManager().State()
 	}
 
-	return self.withState(st)
+	return self.WithState(st)
 }
 
-func (self *XEth) withState(statedb *state.StateDB) *XEth {
+func (self *XEth) WithState(statedb *state.StateDB) *XEth {
 	xeth := &XEth{
 		backend: self.backend,
 	}