func makeTx(outputs []output, amount, value int64, toAddr, changeAddr string) (*btcwire.MsgTx, error) {
	msgTx := btcwire.NewMsgTx()

	for _, op := range outputs {
		hash, err := btcwire.NewShaHashFromStr(op.TxHash)
		if err != nil {
			return nil, err
		}
		b, err := hex.DecodeString(op.Script)
		if err != nil {
			return nil, err
		}
		txIn := btcwire.NewTxIn(btcwire.NewOutPoint(hash, op.TxN), b)
		msgTx.AddTxIn(txIn)
	}

	script, err := makeScriptPubKey(toAddr)
	if err != nil {
		return nil, err
	}
	txOut := btcwire.NewTxOut(value, script)
	msgTx.AddTxOut(txOut)

	if amount > value {
		script, err = makeScriptPubKey(changeAddr)
		if err != nil {
			return nil, err
		}
		txOut := btcwire.NewTxOut(amount-value, script)
		msgTx.AddTxOut(txOut)
	}
	return msgTx, nil
}

// createCoinbaseTx returns a coinbase transaction paying an appropriate subsidy
// based on the passed block height to the provided address.  When the address
// is nil, the coinbase transaction will instead be redeemable by anyone.
//
// See the comment for NewBlockTemplate for more information about why the nil
// address handling is useful.
func createCoinbaseTx(coinbaseScript []byte, nextBlockHeight int64, addr btcutil.Address) (*btcutil.Tx, error) {
	// Create the script to pay to the provided payment address if one was
	// specified.  Otherwise create a script that allows the coinbase to be
	// redeemable by anyone.
	var pkScript []byte
	if addr != nil {
		var err error
		pkScript, err = btcscript.PayToAddrScript(addr)
		if err != nil {
			return nil, err
		}
	} else {
		scriptBuilder := btcscript.NewScriptBuilder()
		pkScript = scriptBuilder.AddOp(btcscript.OP_TRUE).Script()
	}

	tx := btcwire.NewMsgTx()
	tx.AddTxIn(&btcwire.TxIn{
		// Coinbase transactions have no inputs, so previous outpoint is
		// zero hash and max index.
		PreviousOutPoint: *btcwire.NewOutPoint(&btcwire.ShaHash{},
			btcwire.MaxPrevOutIndex),
		SignatureScript: coinbaseScript,
		Sequence:        btcwire.MaxTxInSequenceNum,
	})
	tx.AddTxOut(&btcwire.TxOut{
		Value: btcchain.CalcBlockSubsidy(nextBlockHeight,
			activeNetParams.Params),
		PkScript: pkScript,
	})
	return btcutil.NewTx(tx), nil
}

// TestTxSerialize tests MsgTx serialize and deserialize.
func TestTxSerialize(t *testing.T) {
	noTx := btcwire.NewMsgTx()
	noTx.Version = 1
	noTxEncoded := []byte{
		0x01, 0x00, 0x00, 0x00, // Version
		0x00,                   // Varint for number of input transactions
		0x00,                   // Varint for number of output transactions
		0x00, 0x00, 0x00, 0x00, // Lock time
	}

	tests := []struct {
		in  *btcwire.MsgTx // Message to encode
		out *btcwire.MsgTx // Expected decoded message
		buf []byte         // Serialized data
	}{
		// No transactions.
		{
			noTx,
			noTx,
			noTxEncoded,
		},

		// Multiple transactions.
		{
			multiTx,
			multiTx,
			multiTxEncoded,
		},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Serialize the transaction.
		var buf bytes.Buffer
		err := test.in.Serialize(&buf)
		if err != nil {
			t.Errorf("Serialize #%d error %v", i, err)
			continue
		}
		if !bytes.Equal(buf.Bytes(), test.buf) {
			t.Errorf("Serialize #%d\n got: %s want: %s", i,
				spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
			continue
		}

		// Deserialize the transaction.
		var tx btcwire.MsgTx
		rbuf := bytes.NewReader(test.buf)
		err = tx.Deserialize(rbuf)
		if err != nil {
			t.Errorf("Deserialize #%d error %v", i, err)
			continue
		}
		if !reflect.DeepEqual(&tx, test.out) {
			t.Errorf("Deserialize #%d\n got: %s want: %s", i,
				spew.Sdump(&tx), spew.Sdump(test.out))
			continue
		}
	}
}

// TestTxSerializeSize performs tests to ensure the serialize size for various
// transactions is accurate.
func TestTxSerializeSize(t *testing.T) {
	// Empty tx message.
	noTx := btcwire.NewMsgTx()
	noTx.Version = 1

	tests := []struct {
		in   *btcwire.MsgTx // Tx to encode
		size int            // Expected serialized size
	}{
		// No inputs or outpus.
		{noTx, 10},

		// Transcaction with an input and an output.
		{multiTx, 134},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		serializedSize := test.in.SerializeSize()
		if serializedSize != test.size {
			t.Errorf("MsgTx.SerializeSize: #%d got: %d, want: %d", i,
				serializedSize, test.size)
			continue
		}
	}
}

func (bltnB *BulletinBuilder) Build() (*btcwire.MsgTx, error) {
	utxo, err := selectUnspent(bltnB.SatNeeded(), bltnB.Params)
	if err != nil {
		return nil, err
	}
	msgtx := btcwire.NewMsgTx()
	// Add data storing txouts.
	txouts, err := bltnB.Bulletin.TxOuts(bltnB.BurnAmnt, bltnB.Params.NetParams)
	if err != nil {
		return nil, err
	}
	msgtx.TxOut = txouts

	txin := btcwire.NewTxIn(utxo.OutPoint, []byte{})
	msgtx.AddTxIn(txin)

	// Deal with change
	changeAmnt := utxo.TxOut.Value - bltnB.SatNeeded()
	if changeAmnt > bltnB.Params.DustAmnt {
		changeOut, err := makeChange(changeAmnt, bltnB.Params)
		if err != nil {
			return nil, err
		}
		msgtx.AddTxOut(changeOut)
	}

	// Sign the Bulletin
	privkey := utxo.Wif.PrivKey
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, utxo.TxOut.PkScript, btcscript.SigHashAll, privkey, true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = scriptSig
	return msgtx, nil
}

func (fanB *FanOutBuilder) Build() (*btcwire.MsgTx, error) {
	totalSpent := fanB.SatNeeded()

	// Compose a set of Txins with enough to fund this transactions needs
	inParamSet, totalIn, err := composeUnspents(
		totalSpent,
		fanB.Params)
	if err != nil {
		return nil, err
	}

	msgtx := btcwire.NewMsgTx()
	// funding inputs speced out with blank
	for _, inpParam := range inParamSet {
		txin := btcwire.NewTxIn(inpParam.OutPoint, []byte{})
		msgtx.AddTxIn(txin)
	}

	for i := range fanB.Builders {
		builder := fanB.Builders[i]
		amnt := builder.SatNeeded()
		for j := int64(0); j < fanB.Copies; j++ {
			addr, err := newAddr(fanB.Params.Client)
			if err != nil {
				return nil, err
			}
			script, _ := btcscript.PayToAddrScript(addr)
			txout := btcwire.NewTxOut(amnt, script)
			msgtx.AddTxOut(txout)
		}
	}

	changeAddr, err := newAddr(fanB.Params.Client)
	if err != nil {
		return nil, err
	}
	// change to solve unevenness
	change, ok := changeOutput(totalIn-totalSpent, fanB.Params.DustAmnt, changeAddr)
	if ok {
		msgtx.AddTxOut(change)
	}

	// sign msgtx for each input
	for i, inpParam := range inParamSet {
		privkey := inpParam.Wif.PrivKey
		subscript := inpParam.TxOut.PkScript
		sigflag := btcscript.SigHashAll
		scriptSig, err := btcscript.SignatureScript(msgtx, i, subscript,
			sigflag, privkey, true)
		if err != nil {
			return nil, err
		}
		msgtx.TxIn[i].SignatureScript = scriptSig
	}
	fanB.Log(fmt.Sprintf("InVal: %d\n", sumInputs(inParamSet)))
	fanB.Log(fmt.Sprintf("OutVal: %d\n", sumOutputs(msgtx)))

	return msgtx, nil
}

func TestTxSha(t *testing.T) {
	pver := btcwire.ProtocolVersion

	// Hash of first transaction from block 113875.
	hashStr := "f051e59b5e2503ac626d03aaeac8ab7be2d72ba4b7e97119c5852d70d52dcb86"
	wantHash, err := btcwire.NewShaHashFromStr(hashStr)
	if err != nil {
		t.Errorf("NewShaHashFromStr: %v", err)
		return
	}

	// First transaction from block 113875.
	msgTx := btcwire.NewMsgTx()
	txIn := btcwire.TxIn{
		PreviousOutpoint: btcwire.OutPoint{
			Hash:  btcwire.ShaHash{0x00},
			Index: 0xffffffff,
		},
		SignatureScript: []byte{0x04, 0x31, 0xdc, 0x00, 0x1b, 0x01, 0x62},
		Sequence:        0xffffffff,
	}
	txOut := btcwire.TxOut{
		Value: 5000000000,
		PkScript: []byte{
			0x41, // OP_DATA_65
			0x04, 0xd6, 0x4b, 0xdf, 0xd0, 0x9e, 0xb1, 0xc5,
			0xfe, 0x29, 0x5a, 0xbd, 0xeb, 0x1d, 0xca, 0x42,
			0x81, 0xbe, 0x98, 0x8e, 0x2d, 0xa0, 0xb6, 0xc1,
			0xc6, 0xa5, 0x9d, 0xc2, 0x26, 0xc2, 0x86, 0x24,
			0xe1, 0x81, 0x75, 0xe8, 0x51, 0xc9, 0x6b, 0x97,
			0x3d, 0x81, 0xb0, 0x1c, 0xc3, 0x1f, 0x04, 0x78,
			0x34, 0xbc, 0x06, 0xd6, 0xd6, 0xed, 0xf6, 0x20,
			0xd1, 0x84, 0x24, 0x1a, 0x6a, 0xed, 0x8b, 0x63,
			0xa6, // 65-byte signature
			0xac, // OP_CHECKSIG
		},
	}
	msgTx.AddTxIn(&txIn)
	msgTx.AddTxOut(&txOut)
	msgTx.LockTime = 0

	// Ensure the hash produced is expected.
	txHash, err := msgTx.TxSha(pver)
	if err != nil {
		t.Errorf("TxSha: %v", err)
	}
	if !txHash.IsEqual(wantHash) {
		t.Errorf("TxSha: wrong hash - got %v, want %v",
			spew.Sprint(txHash), spew.Sprint(wantHash))
	}
}

// NewMsgTxWithInputCoins takes the coins in the CoinSet and makes them
// the inputs to a new btcwire.MsgTx which is returned.
func NewMsgTxWithInputCoins(inputCoins Coins) *btcwire.MsgTx {
	msgTx := btcwire.NewMsgTx()
	coins := inputCoins.Coins()
	msgTx.TxIn = make([]*btcwire.TxIn, len(coins))
	for i, coin := range coins {
		msgTx.TxIn[i] = &btcwire.TxIn{
			PreviousOutPoint: btcwire.OutPoint{
				Hash:  *coin.Hash(),
				Index: coin.Index(),
			},
			SignatureScript: nil,
			Sequence:        btcwire.MaxTxInSequenceNum,
		}
	}
	return msgTx
}

// handleSendRawTransaction implements the sendrawtransaction command.
func handleSendRawTransaction(s *rpcServer, cmd btcjson.Cmd) (interface{}, error) {
	c := cmd.(*btcjson.SendRawTransactionCmd)
	// Deserialize and send off to tx relay
	serializedTx, err := hex.DecodeString(c.HexTx)
	if err != nil {
		return nil, btcjson.ErrDecodeHexString
	}
	msgtx := btcwire.NewMsgTx()
	err = msgtx.Deserialize(bytes.NewBuffer(serializedTx))
	if err != nil {
		err := btcjson.Error{
			Code:    btcjson.ErrDeserialization.Code,
			Message: "TX decode failed",
		}
		return nil, err
	}

	tx := btcutil.NewTx(msgtx)
	err = s.server.txMemPool.ProcessTransaction(tx, false)
	if err != nil {
		// When the error is a rule error, it means the transaction was
		// simply rejected as opposed to something actually going wrong,
		// so log it as such.  Otherwise, something really did go wrong,
		// so log it as an actual error.  In both cases, a JSON-RPC
		// error is returned to the client with the deserialization
		// error code (to match bitcoind behavior).
		if _, ok := err.(TxRuleError); ok {
			rpcsLog.Debugf("Rejected transaction %v: %v", tx.Sha(),
				err)
		} else {
			rpcsLog.Errorf("Failed to process transaction %v: %v",
				tx.Sha(), err)
		}
		err = btcjson.Error{
			Code:    btcjson.ErrDeserialization.Code,
			Message: fmt.Sprintf("TX rejected: %v", err),
		}
		return nil, err
	}

	// We keep track of all the sendrawtransaction request txs so that we
	// can rebroadcast them if they don't make their way into a block.
	iv := btcwire.NewInvVect(btcwire.InvTypeTx, tx.Sha())
	s.server.AddRebroadcastInventory(iv)

	return tx.Sha().String(), nil
}

func (shsB *SigHashSingleBuilder) Build() (*btcwire.MsgTx, error) {
	// RPC to setup previous TX
	utxo, err := selectUnspent(shsB.SatNeeded()+shsB.Params.DustAmnt, shsB.Params)
	if err != nil {
		return nil, err
	}

	oldTxOut := utxo.TxOut
	outpoint := utxo.OutPoint
	wifkey := utxo.Wif

	// Transaction building

	txin := btcwire.NewTxIn(outpoint, []byte{})

	// notice amount in
	total := oldTxOut.Value
	changeval := total - (shsB.SatNeeded())
	change, ok := changeOutput(changeval, shsB.Params.DustAmnt,
		wifToAddr(wifkey, shsB.Params.NetParams))
	if !ok {
		return nil, errors.New("Not enough for change.")
	}
	// Blank permutable txout for users to play with
	blankval := shsB.Params.InTarget - shsB.Params.Fee
	blank := btcwire.NewTxOut(blankval, change.PkScript) //[]byte{})

	msgtx := btcwire.NewMsgTx()
	msgtx.AddTxIn(txin)
	msgtx.AddTxOut(change)
	msgtx.AddTxOut(blank)

	subscript := oldTxOut.PkScript
	privkey := wifkey.PrivKey
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, subscript, btcscript.SigHashSingle, privkey, true)
	if err != nil {
		return nil, err
	}

	msgtx.TxIn[0].SignatureScript = scriptSig
	// This demonstrates that we can sign and then permute a txout
	//msgtx.TxOut[1].PkScript = oldTxOut.PkScript
	blank.Value = blankval + 1

	return msgtx, nil
}

// handleSendRawTransaction implements the sendrawtransaction command.
func handleSendRawTransaction(s *rpcServer, cmd btcjson.Cmd, walletNotification chan []byte) (interface{}, error) {
	c := cmd.(*btcjson.SendRawTransactionCmd)
	// Deserialize and send off to tx relay
	serializedTx, err := hex.DecodeString(c.HexTx)
	if err != nil {
		return nil, btcjson.ErrDecodeHexString
	}
	msgtx := btcwire.NewMsgTx()
	err = msgtx.Deserialize(bytes.NewBuffer(serializedTx))
	if err != nil {
		err := btcjson.Error{
			Code:    btcjson.ErrDeserialization.Code,
			Message: "Unable to deserialize raw tx",
		}
		return nil, err
	}

	tx := btcutil.NewTx(msgtx)
	err = s.server.txMemPool.ProcessTransaction(tx)
	if err != nil {
		// When the error is a rule error, it means the transaction was
		// simply rejected as opposed to something actually going wrong,
		// so log it as such.  Otherwise, something really did go wrong,
		// so log it as an actual error.
		if _, ok := err.(TxRuleError); ok {
			log.Debugf("RPCS: Rejected transaction %v: %v", tx.Sha(),
				err)
		} else {
			log.Errorf("RPCS: Failed to process transaction %v: %v",
				tx.Sha(), err)
		}
		err = btcjson.Error{
			Code:    btcjson.ErrDeserialization.Code,
			Message: "Failed to process transaction",
		}
		return nil, err
	}

	// If called from websocket code, add a mined tx hashes
	// request.
	if walletNotification != nil {
		s.ws.requests.AddMinedTxRequest(walletNotification, tx.Sha())
	}

	return tx.Sha().String(), nil
}

// TestCheckSerializedHeight tests the checkSerializedHeight function with
// various serialized heights and also does negative tests to ensure errors
// and handled properly.
func TestCheckSerializedHeight(t *testing.T) {
	// Create an empty coinbase template to be used in the tests below.
	coinbaseOutpoint := btcwire.NewOutPoint(&btcwire.ShaHash{}, math.MaxUint32)
	coinbaseTx := btcwire.NewMsgTx()
	coinbaseTx.Version = 2
	coinbaseTx.AddTxIn(btcwire.NewTxIn(coinbaseOutpoint, nil))

	//
	tests := []struct {
		sigScript  []byte // Serialized data
		wantHeight int64  // Expected height
		err        error  // Expected error type
	}{
		// No serialized height length.
		{[]byte{}, 0, btcchain.RuleError("")},
		// Serialized height length with no height bytes.
		{[]byte{0x02}, 0, btcchain.RuleError("")},
		// Serialized height length with too few height bytes.
		{[]byte{0x02, 0x4a}, 0, btcchain.RuleError("")},
		// Serialized height that needs 2 bytes to encode.
		{[]byte{0x02, 0x4a, 0x52}, 21066, nil},
		// Serialized height that needs 2 bytes to encode, but backwards
		// endianness.
		{[]byte{0x02, 0x4a, 0x52}, 19026, btcchain.RuleError("")},
		// Serialized height that needs 3 bytes to encode.
		{[]byte{0x03, 0x40, 0x0d, 0x03}, 200000, nil},
		// Serialized height that needs 3 bytes to encode, but backwards
		// endianness.
		{[]byte{0x03, 0x40, 0x0d, 0x03}, 1074594560, btcchain.RuleError("")},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		msgTx := coinbaseTx.Copy()
		msgTx.TxIn[0].SignatureScript = test.sigScript
		tx := btcutil.NewTx(msgTx)

		err := btcchain.TstCheckSerializedHeight(tx, test.wantHeight)
		if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
			t.Errorf("checkSerializedHeight #%d wrong error type "+
				"got: %v <%T>, want: %T", i, err, err, test.err)
			continue
		}
	}
}

func (builder *ToAddrBuilder) Build() (*btcwire.MsgTx, error) {

	utxo, err := selectUnspent(builder.SatNeeded(), builder.Params)
	if err != nil {
		return nil, err
	}

	txin := btcwire.NewTxIn(utxo.OutPoint, []byte{})

	msgtx := btcwire.NewMsgTx()
	msgtx.AddTxIn(txin)
	// add send to addr
	valout := builder.Params.InTarget - builder.Params.Fee
	outscript, _ := btcscript.PayToAddrScript(builder.Addr)
	txout := btcwire.NewTxOut(valout, outscript)

	msgtx.AddTxOut(txout)

	// add send to change addr
	total := utxo.TxOut.Value
	changeval := total - builder.SatNeeded()
	if changeval > builder.Params.DustAmnt {
		// Change needed
		changeAddr, err := builder.Params.Client.GetNewAddress()
		if err != nil {
			return nil, err
		}
		change, ok := changeOutput(changeval, builder.Params.DustAmnt, changeAddr)
		if ok {
			msgtx.AddTxOut(change)
		}
	}

	subscript := utxo.TxOut.PkScript
	privkey := utxo.Wif.PrivKey
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, subscript, btcscript.SigHashAll, privkey, true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = scriptSig

	return msgtx, nil
}

func (ndB *NullDataBuilder) Build() (*btcwire.MsgTx, error) {

	utxo, err := specificUnspent(ndB.SatNeeded(), ndB.Params)
	if err != nil {
		return nil, err
	}

	msgtx := btcwire.NewMsgTx()

	if len(ndB.Data) > 40 {
		return nil, errors.New("Data is too long to make this a standard tx.")
	}

	// OP Return output
	retbuilder := btcscript.NewScriptBuilder().AddOp(btcscript.OP_RETURN).AddData(ndB.Data)
	op_return := btcwire.NewTxOut(0, retbuilder.Script())
	msgtx.AddTxOut(op_return)

	if ndB.Change {
		// change ouput
		addr, _ := newAddr(ndB.Params.Client)
		change, ok := changeOutput(ndB.SatNeeded()-ndB.Params.Fee, ndB.Params.DustAmnt, addr)
		if !ok {
			return nil, errors.New("Not enough for change")
		}
		msgtx.AddTxOut(change)
	}

	// funding input
	txin := btcwire.NewTxIn(utxo.OutPoint, []byte{})
	msgtx.AddTxIn(txin)

	// sign msgtx
	privkey := utxo.Wif.PrivKey
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, utxo.TxOut.PkScript, btcscript.SigHashAll, privkey, true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = scriptSig

	return msgtx, nil
}

// A transaction that contains only dust ouputs and obeys the TxBuilder interface
func (builder *DustBuilder) Build() (*btcwire.MsgTx, error) {

	var inparams *TxInParams
	var err error
	inparams, err = specificUnspent(
		builder.SatNeeded(),
		builder.Params)
	if err != nil {
		return nil, err
	}

	oldTxOut := inparams.TxOut
	outpoint := inparams.OutPoint
	wifkey := inparams.Wif

	msgtx := btcwire.NewMsgTx()

	txin := btcwire.NewTxIn(outpoint, []byte{})
	msgtx.AddTxIn(txin)

	for i := int64(0); i < builder.NumOuts; i++ {
		dumb := bytes.Repeat([]byte{66}, 20)
		addr := dataAddr(dumb, builder.Params.NetParams)
		addrScript, err := btcscript.PayToAddrScript(addr)
		if err != nil {
			return nil, err
		}
		txOut := btcwire.NewTxOut(builder.Params.DustAmnt, addrScript)
		msgtx.AddTxOut(txOut)
	}

	// sign as usual
	privkey := wifkey.PrivKey
	sig, err := btcscript.SignatureScript(msgtx, 0, oldTxOut.PkScript, btcscript.SigHashAll, privkey, true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = sig

	return msgtx, nil
}

// handleSendRawTransaction implements the sendrawtransaction command.
func handleSendRawTransaction(s *rpcServer, cmd btcjson.Cmd) (interface{}, error) {
	c := cmd.(*btcjson.SendRawTransactionCmd)
	// Deserialize and send off to tx relay
	serializedTx, err := hex.DecodeString(c.HexTx)
	if err != nil {
		return nil, btcjson.ErrDecodeHexString
	}
	msgtx := btcwire.NewMsgTx()
	err = msgtx.Deserialize(bytes.NewBuffer(serializedTx))
	if err != nil {
		err := btcjson.Error{
			Code:    btcjson.ErrDeserialization.Code,
			Message: "TX decode failed",
		}
		return nil, err
	}

	tx := btcutil.NewTx(msgtx)
	err = s.server.txMemPool.ProcessTransaction(tx)
	if err != nil {
		// When the error is a rule error, it means the transaction was
		// simply rejected as opposed to something actually going wrong,
		// so log it as such.  Otherwise, something really did go wrong,
		// so log it as an actual error.
		if _, ok := err.(TxRuleError); ok {
			rpcsLog.Debugf("Rejected transaction %v: %v", tx.Sha(),
				err)
		} else {
			rpcsLog.Errorf("Failed to process transaction %v: %v",
				tx.Sha(), err)
			err = btcjson.Error{
				Code:    btcjson.ErrDeserialization.Code,
				Message: "TX rejected",
			}
			return nil, err
		}
	}

	return tx.Sha().String(), nil
}

func (pkhB *PubKeyHashBuilder) Build() (*btcwire.MsgTx, error) {

	inparams, err := specificUnspent(pkhB.SatNeeded(), pkhB.Params)
	if err != nil {
		return nil, err
	}

	msgtx := btcwire.NewMsgTx()

	txin := btcwire.NewTxIn(inparams.OutPoint, []byte{})
	msgtx.AddTxIn(txin)

	for i := int64(0); i < pkhB.NumOuts; i++ {
		addr, err := newAddr(pkhB.Params.Client)
		if err != nil {
			return nil, err
		}
		addrScript, err := btcscript.PayToAddrScript(addr)
		amntSend := pkhB.eachOutVal()
		if amntSend < pkhB.Params.DustAmnt {
			return nil, errors.New("Output would be under the dust limit")
		}
		txout := btcwire.NewTxOut(pkhB.eachOutVal(), addrScript)
		msgtx.AddTxOut(txout)
	}
	privkey := inparams.Wif.PrivKey
	sig, err := btcscript.SignatureScript(msgtx,
		0,
		inparams.TxOut.PkScript,
		btcscript.SigHashAll,
		privkey,
		true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = sig

	return msgtx, nil
}

// createCoinbaseTx returns a coinbase transaction paying an appropriate subsidy
// based on the passed block height to the passed public key.  It also accepts
// an extra nonce value for the signature script.  This extra nonce helps ensure
// the transaction is not a duplicate transaction (paying the same value to the
// same public key address would otherwise be an identical transaction for
// block version 1).
func createCoinbaseTx(coinbaseScript []byte, nextBlockHeight int64, addr btcutil.Address) (*btcutil.Tx, error) {
	// Create a script to pay to the specific address.
	pkScript, err := btcscript.PayToAddrScript(addr)
	if err != nil {
		return nil, err
	}

	tx := btcwire.NewMsgTx()
	tx.AddTxIn(&btcwire.TxIn{
		// Coinbase transactions have no inputs, so previous outpoint is
		// zero hash and max index.
		PreviousOutpoint: *btcwire.NewOutPoint(&btcwire.ShaHash{},
			btcwire.MaxPrevOutIndex),
		SignatureScript: coinbaseScript,
		Sequence:        btcwire.MaxTxInSequenceNum,
	})
	tx.AddTxOut(&btcwire.TxOut{
		Value: btcchain.CalcBlockSubsidy(nextBlockHeight,
			activeNetParams.Params),
		PkScript: pkScript,
	})
	return btcutil.NewTx(tx), nil
}

// Returns the "Author" who signed the first txin of the transaction
func getAuthor(tx *btcwire.MsgTx, net *btcnet.Params) (string, error) {
	sigScript := tx.TxIn[0].SignatureScript

	dummyTx := btcwire.NewMsgTx()

	// Setup a script executor to parse the raw bytes of the signature script.
	script, err := btcscript.NewScript(sigScript, make([]byte, 0), 0, dummyTx, 0)
	if err != nil {
		return "", err
	}
	// Step twice due to <sig> <pubkey> format of pay 2pubkeyhash
	script.Step()
	script.Step()
	// Pull off the <pubkey>
	pkBytes := script.GetStack()[1]

	addrPubKey, err := btcutil.NewAddressPubKey(pkBytes, net)
	if err != nil {
		return "", err
	}

	return addrPubKey.EncodeAddress(), nil
}

// TODO This will add multisig Txouts to the unspent set be AWARE
func (msB *MultiSigBuilder) Build() (*btcwire.MsgTx, error) {

	utxo, err := specificUnspent(msB.SatNeeded(), msB.Params)
	if err != nil {
		return nil, err
	}
	msgtx := btcwire.NewMsgTx()

	txin := btcwire.NewTxIn(utxo.OutPoint, []byte{})
	msgtx.AddTxIn(txin)

	for _, pubkeys := range msB.PubKeyList {
		// M pubkey pubkey pubkey N OP_CHECKMULTISIG
		scriptBuilder := btcscript.NewScriptBuilder().AddInt64(msB.M)
		for _, pk := range pubkeys {
			scriptBuilder = scriptBuilder.AddData(pk)
		}
		scriptBuilder = scriptBuilder.AddInt64(msB.N).AddOp(btcscript.OP_CHECKMULTISIG)
		PkScript := scriptBuilder.Script()
		txout := btcwire.NewTxOut(msB.eachOutVal(), PkScript)
		msgtx.AddTxOut(txout)
	}

	// Sign this puppy
	privkey := utxo.Wif.PrivKey
	subscript := utxo.TxOut.PkScript
	sigflag := btcscript.SigHashAll
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, subscript,
		sigflag, privkey, true)
	if err != nil {
		return nil, err
	}

	msgtx.TxIn[0].SignatureScript = scriptSig

	return msgtx, nil
}