diff --git a/app/app.go b/app/app.go
index c96be39dd..d9b91fe20 100644
--- a/app/app.go
+++ b/app/app.go
@@ -12,23 +12,34 @@ import (
 	tmsp "github.com/tendermint/tmsp/types"
 )
 
-const version = "0.1"
-const maxTxSize = 10240
+const (
+	version   = "0.1"
+	maxTxSize = 10240
+
+	typeByteBase = 0x01
+	typeByteGov  = 0x02
+
+	pluginNameBase = "base"
+	pluginNameGov  = "gov"
+)
 
 type Basecoin struct {
 	eyesCli *eyes.Client
 	govMint *gov.Governmint
 	state   *state.State
+	plugins *types.Plugins
 }
 
 func NewBasecoin(eyesCli *eyes.Client) *Basecoin {
-	state_ := state.NewState(eyesCli)
 	govMint := gov.NewGovernmint(eyesCli)
-	state_.RegisterPlugin("GOV", govMint)
+	state_ := state.NewState(eyesCli)
+	plugins := types.NewPlugins()
+	plugins.RegisterPlugin(typeByteGov, pluginNameGov, govMint) // TODO: make constants
 	return &Basecoin{
 		eyesCli: eyesCli,
 		govMint: govMint,
 		state:   state_,
+		plugins: plugins,
 	}
 }
 
@@ -39,11 +50,10 @@ func (app *Basecoin) Info() string {
 
 // TMSP::SetOption
 func (app *Basecoin) SetOption(key string, value string) (log string) {
-
 	pluginName, key := splitKey(key)
-	if pluginName != "BASE" {
+	if pluginName != pluginNameBase {
 		// Set option on plugin
-		plugin := app.state.GetPlugin(pluginName)
+		plugin := app.plugins.GetByName(pluginName)
 		if plugin == nil {
 			return "Invalid plugin name: " + pluginName
 		}
@@ -84,7 +94,7 @@ func (app *Basecoin) AppendTx(txBytes []byte) (res tmsp.Result) {
 		return tmsp.ErrBaseEncodingError.AppendLog("Error decoding tx: " + err.Error())
 	}
 	// Validate and exec tx
-	res = state.ExecTx(app.state, tx, false, nil)
+	res = state.ExecTx(app.state, app.plugins, tx, false, nil)
 	if res.IsErr() {
 		return res.PrependLog("Error in AppendTx")
 	}
@@ -103,7 +113,7 @@ func (app *Basecoin) CheckTx(txBytes []byte) (res tmsp.Result) {
 		return tmsp.ErrBaseEncodingError.AppendLog("Error decoding tx: " + err.Error())
 	}
 	// Validate tx
-	res = state.ExecTx(app.state, tx, true, nil)
+	res = state.ExecTx(app.state, app.plugins, tx, true, nil)
 	if res.IsErr() {
 		return res.PrependLog("Error in CheckTx")
 	}
@@ -113,8 +123,8 @@ func (app *Basecoin) CheckTx(txBytes []byte) (res tmsp.Result) {
 // TMSP::Query
 func (app *Basecoin) Query(query []byte) (res tmsp.Result) {
 	pluginName, queryStr := splitKey(string(query))
-	if pluginName != "BASE" {
-		plugin := app.state.GetPlugin(pluginName)
+	if pluginName != pluginNameBase {
+		plugin := app.plugins.GetByName(pluginName)
 		if plugin == nil {
 			return tmsp.ErrBaseUnknownPlugin.SetLog(Fmt("Unknown plugin %v", pluginName))
 		}
@@ -132,7 +142,7 @@ func (app *Basecoin) Query(query []byte) (res tmsp.Result) {
 // TMSP::Commit
 func (app *Basecoin) Commit() (res tmsp.Result) {
 	// First, commit all the plugins
-	for _, plugin := range app.state.GetPlugins() {
+	for _, plugin := range app.plugins.GetList() {
 		res = plugin.Commit()
 		if res.IsErr() {
 			PanicSanity(Fmt("Error committing plugin %v", plugin.Name))
@@ -162,8 +172,8 @@ func (app *Basecoin) EndBlock(height uint64) []*tmsp.Validator {
 // Splits the string at the first :.
 // if there are none, the second string is nil.
 func splitKey(key string) (prefix string, sufix string) {
-	if strings.Contains(key, ":") {
-		keyParts := strings.SplitN(key, ":", 2)
+	if strings.Contains(key, "/") {
+		keyParts := strings.SplitN(key, "/", 2)
 		return keyParts[0], keyParts[1]
 	}
 	return key, ""
diff --git a/cmd/basecoin/main.go b/cmd/basecoin/main.go
index ff7c3248e..fec7c7947 100644
--- a/cmd/basecoin/main.go
+++ b/cmd/basecoin/main.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"reflect"
 
 	"github.com/tendermint/basecoin/app"
 	. "github.com/tendermint/go-common"
@@ -58,14 +59,36 @@ type KeyValue struct {
 }
 
 func loadGenesis(filePath string) (kvz []KeyValue) {
+	kvz_ := []interface{}{}
 	bytes, err := ReadFile(filePath)
 	if err != nil {
 		Exit("loading genesis file: " + err.Error())
 	}
-	fmt.Println(">>", string(bytes))
-	err = json.Unmarshal(bytes, &kvz)
+	err = json.Unmarshal(bytes, &kvz_)
 	if err != nil {
 		Exit("parsing genesis file: " + err.Error())
 	}
-	return
+	if len(kvz_)%2 != 0 {
+		Exit("genesis cannot have an odd number of items.  Format = [key1, value1, key2, value2, ...]")
+	}
+	for i := 0; i < len(kvz_)/2; i++ {
+		keyIfc := kvz_[i]
+		valueIfc := kvz_[i+1]
+		var key, value string
+		key, ok := keyIfc.(string)
+		if !ok {
+			Exit(Fmt("genesis had invalid key %v of type %v", keyIfc, reflect.TypeOf(keyIfc)))
+		}
+		if value_, ok := valueIfc.(string); ok {
+			value = value_
+		} else {
+			valueBytes, err := json.Marshal(value_)
+			if err != nil {
+				Exit(Fmt("genesis had invalid value %v: %v", value_, err.Error()))
+			}
+			value = string(valueBytes)
+		}
+		kvz = append(kvz, KeyValue{key, value})
+	}
+	return kvz
 }
diff --git a/genesis.json b/genesis.json
index 6c971f67a..92876231a 100644
--- a/genesis.json
+++ b/genesis.json
@@ -1,10 +1,7 @@
 [
-  {
-    "key":    "chainID",
-    "value":  "test_chain_id"
-  },
-  {
-    "key":    "account",
-    "value":  "{\"pub_key\":[1,\"3E8A80E5412FD1711995D5888F5FA2EFB26EDD0970F1E27CE0B55CD237439E18\"],\"balance\":1000}"
+  "base/chainID", "test_chain_id",
+  "base/account", {
+    "pub_key", [1, "67D3B5EAF0C0BF6B5A602D359DAECC86A7A74053490EC37AE08E71360587C870"],
+    "balance": 1000
   }
 ]
diff --git a/state/execution.go b/state/execution.go
index 2d35f0061..318921c15 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -10,7 +10,7 @@ import (
 )
 
 // If the tx is invalid, a TMSP error will be returned.
-func ExecTx(state *State, tx types.Tx, isCheckTx bool, evc events.Fireable) tmsp.Result {
+func ExecTx(state *State, pgz *types.Plugins, tx types.Tx, isCheckTx bool, evc events.Fireable) tmsp.Result {
 
 	// TODO: do something with fees
 	fees := int64(0)
@@ -68,7 +68,7 @@ func ExecTx(state *State, tx types.Tx, isCheckTx bool, evc events.Fireable) tmsp
 
 		return tmsp.OK
 
-	case *types.CallTx:
+	case *types.AppTx:
 		// First, get input account
 		inAcc := state.GetAccount(tx.Input.Address)
 		if inAcc == nil {
@@ -93,9 +93,10 @@ func ExecTx(state *State, tx types.Tx, isCheckTx bool, evc events.Fireable) tmsp
 		}
 
 		// Validate call address
-		plugin := state.GetPlugin(string(tx.Address))
+		plugin := pgz.GetByByte(tx.Type)
 		if plugin != nil {
-			return tmsp.ErrBaseUnknownAddress.AppendLog(Fmt("Unrecognized address %X (%v)", tx.Address, string(tx.Address)))
+			return tmsp.ErrBaseUnknownAddress.AppendLog(
+				Fmt("Unrecognized type byte %v", tx.Type))
 		}
 
 		// Good!
@@ -105,7 +106,7 @@ func ExecTx(state *State, tx types.Tx, isCheckTx bool, evc events.Fireable) tmsp
 		state.SetCheckAccount(tx.Input.Address, inAcc.Sequence, inAcc.Balance)
 		inAccCopy := inAcc.Copy()
 
-		// If this is AppendTx, actually save accounts
+		// If this is a CheckTx, stop now.
 		if isCheckTx {
 			return tmsp.OK
 		}
@@ -115,7 +116,7 @@ func ExecTx(state *State, tx types.Tx, isCheckTx bool, evc events.Fireable) tmsp
 		cache.SetAccount(tx.Input.Address, inAcc)
 		gas := int64(1) // TODO
 		ctx := types.NewCallContext(cache, inAcc, value, &gas)
-		res = plugin.CallTx(ctx, tx.Data)
+		res = plugin.RunTx(ctx, tx.Data)
 		if res.IsOK() {
 			cache.Sync()
 			log.Info("Successful execution")
@@ -131,7 +132,7 @@ func ExecTx(state *State, tx types.Tx, isCheckTx bool, evc events.Fireable) tmsp
 				}
 			*/
 		} else {
-			log.Info("CallTx failed", "error", res)
+			log.Info("AppTx failed", "error", res)
 			// Just return the value and return.
 			// TODO: return gas?
 			inAccCopy.Balance += value
diff --git a/state/state.go b/state/state.go
index ac17ff0ae..3d2794c79 100644
--- a/state/state.go
+++ b/state/state.go
@@ -8,11 +8,9 @@ import (
 )
 
 type State struct {
-	chainID     string
-	eyesCli     *eyes.Client
-	checkCache  map[string]checkAccount
-	plugins     map[string]types.Plugin
-	pluginsList []types.NamedPlugin
+	chainID    string
+	eyesCli    *eyes.Client
+	checkCache map[string]checkAccount
 
 	LastBlockHeight uint64
 	LastBlockHash   []byte
@@ -24,7 +22,6 @@ func NewState(eyesCli *eyes.Client) *State {
 		chainID:    "",
 		eyesCli:    eyesCli,
 		checkCache: make(map[string]checkAccount),
-		plugins:    make(map[string]types.Plugin),
 	}
 	return s
 }
@@ -40,22 +37,6 @@ func (s *State) GetChainID() string {
 	return s.chainID
 }
 
-func (s *State) RegisterPlugin(name string, plugin types.Plugin) {
-	s.plugins[name] = plugin
-	s.pluginsList = append(s.pluginsList, types.NamedPlugin{
-		Name:   name,
-		Plugin: plugin,
-	})
-}
-
-func (s *State) GetPlugin(name string) types.Plugin {
-	return s.plugins[name]
-}
-
-func (s *State) GetPlugins() []types.NamedPlugin {
-	return s.pluginsList
-}
-
 //----------------------------------------
 // CheckTx state
 
diff --git a/tests/tmsp/main.go b/tests/tmsp/main.go
index 89a15315f..7f0eb583e 100644
--- a/tests/tmsp/main.go
+++ b/tests/tmsp/main.go
@@ -13,7 +13,7 @@ import (
 )
 
 func main() {
-	//testSendTx()
+	testSendTx()
 	testGov()
 }
 
@@ -28,8 +28,8 @@ func testSendTx() {
 	// Seed Basecoin with account
 	tAcc := tPriv.Account
 	tAcc.Balance = 1000
-	bcApp.SetOption("chainID", "test_chain_id")
-	bcApp.SetOption("account", string(wire.JSONBytes(tAcc)))
+	fmt.Println(bcApp.SetOption("base/chainID", "test_chain_id"))
+	fmt.Println(bcApp.SetOption("base/account", string(wire.JSONBytes(tAcc))))
 
 	// Construct a SendTx signature
 	tx := &types.SendTx{
@@ -51,10 +51,11 @@ func testSendTx() {
 
 	// Sign request
 	signBytes := tx.SignBytes("test_chain_id")
-	fmt.Printf("SIGNBYTES %X", signBytes)
+	fmt.Printf("Sign bytes: %X\n", signBytes)
 	sig := tPriv.PrivKey.Sign(signBytes)
 	tx.Inputs[0].Signature = sig
 	//fmt.Println("tx:", tx)
+	fmt.Printf("Signed TX bytes: %X\n", wire.BinaryBytes(tx))
 
 	// Write request
 	txBytes := wire.BinaryBytes(tx)
@@ -78,7 +79,7 @@ func testGov() {
 		ID:     "",
 		PubKey: tAcc.PubKey,
 	}
-	log := bcApp.SetOption("GOV:admin", string(wire.JSONBytes(adminEntity)))
+	log := bcApp.SetOption("gov/admin", string(wire.JSONBytes(adminEntity)))
 	if log != "Success" {
 		Exit(Fmt("Failed to set option: %v", log))
 	}
diff --git a/types/plugin.go b/types/plugin.go
index 0a4bd9370..3ab6f176b 100644
--- a/types/plugin.go
+++ b/types/plugin.go
@@ -9,16 +9,19 @@ import (
 // if any gas is left the user is
 type Plugin interface {
 	SetOption(key string, value string) (log string)
-	CallTx(ctx CallContext, txBytes []byte) (res tmsp.Result)
+	RunTx(ctx CallContext, txBytes []byte) (res tmsp.Result)
 	Query(query []byte) (res tmsp.Result)
 	Commit() (res tmsp.Result)
 }
 
 type NamedPlugin struct {
+	Byte byte
 	Name string
 	Plugin
 }
 
+//----------------------------------------
+
 type CallContext struct {
 	Cache  AccountCacher
 	Caller *Account
@@ -34,3 +37,40 @@ func NewCallContext(cache AccountCacher, caller *Account, value int64, gas *int6
 		Gas:    gas,
 	}
 }
+
+//----------------------------------------
+
+type Plugins struct {
+	byByte map[byte]Plugin
+	byName map[string]Plugin
+	plist  []NamedPlugin
+}
+
+func NewPlugins() *Plugins {
+	return &Plugins{
+		byByte: make(map[byte]Plugin),
+		byName: make(map[string]Plugin),
+	}
+}
+
+func (pgz *Plugins) RegisterPlugin(typeByte byte, name string, plugin Plugin) {
+	pgz.byByte[typeByte] = plugin
+	pgz.byName[name] = plugin
+	pgz.plist = append(pgz.plist, NamedPlugin{
+		Byte:   typeByte,
+		Name:   name,
+		Plugin: plugin,
+	})
+}
+
+func (pgz *Plugins) GetByByte(typeByte byte) Plugin {
+	return pgz.byByte[typeByte]
+}
+
+func (pgz *Plugins) GetByName(name string) Plugin {
+	return pgz.byName[name]
+}
+
+func (pgz *Plugins) GetList() []NamedPlugin {
+	return pgz.plist
+}
diff --git a/types/tx.go b/types/tx.go
index d16aebd11..feb509b46 100644
--- a/types/tx.go
+++ b/types/tx.go
@@ -1,14 +1,12 @@
 package types
 
 import (
-	"bytes"
 	"encoding/json"
 
 	. "github.com/tendermint/go-common"
 	"github.com/tendermint/go-crypto"
 	"github.com/tendermint/go-wire"
 	tmsp "github.com/tendermint/tmsp/types"
-	"golang.org/x/crypto/ripemd160"
 )
 
 /*
@@ -16,7 +14,7 @@ Tx (Transaction) is an atomic operation on the ledger state.
 
 Account Types:
  - SendTx         Send coins to address
- - CallTx         Send a msg to a contract that runs in the vm
+ - AppTx         Send a msg to a contract that runs in the vm
 */
 
 type Tx interface {
@@ -27,13 +25,13 @@ type Tx interface {
 const (
 	// Account transactions
 	TxTypeSend = byte(0x01)
-	TxTypeCall = byte(0x02)
+	TxTypeApp  = byte(0x02)
 )
 
 var _ = wire.RegisterInterface(
 	struct{ Tx }{},
 	wire.ConcreteType{&SendTx{}, TxTypeSend},
-	wire.ConcreteType{&CallTx{}, TxTypeCall},
+	wire.ConcreteType{&AppTx{}, TxTypeApp},
 )
 
 //-----------------------------------------------------------------------------
@@ -56,11 +54,6 @@ func (txIn TxInput) ValidateBasic() tmsp.Result {
 	return tmsp.OK
 }
 
-func (txIn TxInput) SignBytes() []byte {
-	return []byte(Fmt(`{"address":"%X","amount":%v,"sequence":%v}`,
-		txIn.Address, txIn.Amount, txIn.Sequence))
-}
-
 func (txIn TxInput) String() string {
 	return Fmt("TxInput{%X,%v,%v,%v,%v}", txIn.Address, txIn.Amount, txIn.Sequence, txIn.Signature, txIn.PubKey)
 }
@@ -82,11 +75,6 @@ func (txOut TxOutput) ValidateBasic() tmsp.Result {
 	return tmsp.OK
 }
 
-func (txOut TxOutput) SignBytes() []byte {
-	return []byte(Fmt(`{"address":"%X","amount":%v}`,
-		txOut.Address, txOut.Amount))
-}
-
 func (txOut TxOutput) String() string {
 	return Fmt("TxOutput{%X,%v}", txOut.Address, txOut.Amount)
 }
@@ -99,24 +87,17 @@ type SendTx struct {
 }
 
 func (tx *SendTx) SignBytes(chainID string) []byte {
-	var buf = new(bytes.Buffer)
-	buf.Write([]byte(Fmt(`{"chain_id":%s`, jsonEscape(chainID))))
-	buf.Write([]byte(Fmt(`,"tx":[%v,{"inputs":[`, TxTypeSend)))
-	for i, in := range tx.Inputs {
-		buf.Write(in.SignBytes())
-		if i != len(tx.Inputs)-1 {
-			buf.Write([]byte(","))
-		}
+	signBytes := wire.BinaryBytes(chainID)
+	sigz := make([]crypto.Signature, len(tx.Inputs))
+	for i, input := range tx.Inputs {
+		sigz[i] = input.Signature
+		tx.Inputs[i].Signature = nil
 	}
-	buf.Write([]byte(`],"outputs":[`))
-	for i, out := range tx.Outputs {
-		buf.Write(out.SignBytes())
-		if i != len(tx.Outputs)-1 {
-			buf.Write([]byte(","))
-		}
+	signBytes = append(signBytes, wire.BinaryBytes(tx)...)
+	for i := range tx.Inputs {
+		tx.Inputs[i].Signature = sigz[i]
 	}
-	buf.Write([]byte(`]}]}`))
-	return buf.Bytes()
+	return signBytes
 }
 
 func (tx *SendTx) String() string {
@@ -125,35 +106,25 @@ func (tx *SendTx) String() string {
 
 //-----------------------------------------------------------------------------
 
-type CallTx struct {
-	Input    TxInput `json:"input"`
-	Address  []byte  `json:"address"`
-	GasLimit int64   `json:"gas_limit"`
-	Fee      int64   `json:"fee"`
-	Data     []byte  `json:"data"`
+type AppTx struct {
+	Type  byte    `json:"type"` // Which app
+	Gas   int64   `json:"gas"`
+	Fee   int64   `json:"fee"`
+	Input TxInput `json:"input"`
+	Data  []byte  `json:"data"`
 }
 
-func (tx *CallTx) SignBytes(chainID string) []byte {
-	var buf = new(bytes.Buffer)
-	buf.Write([]byte(Fmt(`{"chain_id":%s`, jsonEscape(chainID))))
-	buf.Write([]byte(Fmt(`,"tx":[%v,{"address":"%X","data":"%X"`, TxTypeCall, tx.Address, tx.Data)))
-	buf.Write([]byte(Fmt(`,"fee":%v,"gas_limit":%v,"input":`, tx.Fee, tx.GasLimit)))
-	buf.Write(tx.Input.SignBytes())
-	buf.Write([]byte(`}]}`))
-	return buf.Bytes()
+func (tx *AppTx) SignBytes(chainID string) []byte {
+	signBytes := wire.BinaryBytes(chainID)
+	sig := tx.Input.Signature
+	tx.Input.Signature = nil
+	signBytes = append(signBytes, wire.BinaryBytes(tx)...)
+	tx.Input.Signature = sig
+	return signBytes
 }
 
-func (tx *CallTx) String() string {
-	return Fmt("CallTx{%v -> %x: %x}", tx.Input, tx.Address, tx.Data)
-}
-
-func NewContractAddress(caller []byte, nonce int) []byte {
-	temp := make([]byte, 32+8)
-	copy(temp, caller)
-	PutInt64BE(temp[32:], int64(nonce))
-	hasher := ripemd160.New()
-	hasher.Write(temp) // does not error
-	return hasher.Sum(nil)
+func (tx *AppTx) String() string {
+	return Fmt("AppTx{%v %v %v %v -> %X}", tx.Type, tx.Gas, tx.Fee, tx.Input, tx.Data)
 }
 
 //-----------------------------------------------------------------------------
diff --git a/types/tx_test.go b/types/tx_test.go
index 20ebf6ac2..49530424f 100644
--- a/types/tx_test.go
+++ b/types/tx_test.go
@@ -34,31 +34,29 @@ func TestSendTxSignable(t *testing.T) {
 		},
 	}
 	signBytes := sendTx.SignBytes(chainID)
-	signStr := string(signBytes)
-	expected := Fmt(`{"chain_id":"%s","tx":[1,{"inputs":[{"address":"696E70757431","amount":12345,"sequence":67890},{"address":"696E70757432","amount":111,"sequence":222}],"outputs":[{"address":"6F757470757431","amount":333},{"address":"6F757470757432","amount":444}]}]}`,
-		chainID)
-	if signStr != expected {
-		t.Errorf("Got unexpected sign string for SendTx. Expected:\n%v\nGot:\n%v", expected, signStr)
+	signBytesHex := Fmt("%X", signBytes)
+	expected := "010A746573745F636861696E0101020106696E7075743100000000000030390301093200000106696E70757432000000000000006F01DE0000010201076F757470757431000000000000014D01076F75747075743200000000000001BC"
+	if signBytesHex != expected {
+		t.Errorf("Got unexpected sign string for SendTx. Expected:\n%v\nGot:\n%v", expected, signBytesHex)
 	}
 }
 
-func TestCallTxSignable(t *testing.T) {
-	callTx := &CallTx{
+func TestAppTxSignable(t *testing.T) {
+	callTx := &AppTx{
+		Type: 0x01,
+		Gas:  111,
+		Fee:  222,
 		Input: TxInput{
 			Address:  []byte("input1"),
 			Amount:   12345,
 			Sequence: 67890,
 		},
-		Address:  []byte("contract1"),
-		GasLimit: 111,
-		Fee:      222,
-		Data:     []byte("data1"),
+		Data: []byte("data1"),
 	}
 	signBytes := callTx.SignBytes(chainID)
-	signStr := string(signBytes)
-	expected := Fmt(`{"chain_id":"%s","tx":[2,{"address":"636F6E747261637431","data":"6461746131","fee":222,"gas_limit":111,"input":{"address":"696E70757431","amount":12345,"sequence":67890}}]}`,
-		chainID)
-	if signStr != expected {
-		t.Errorf("Got unexpected sign string for CallTx. Expected:\n%v\nGot:\n%v", expected, signStr)
+	signBytesHex := Fmt("%X", signBytes)
+	expected := "010A746573745F636861696E0101000000000000006F00000000000000DE0106696E70757431000000000000303903010932000001056461746131"
+	if signBytesHex != expected {
+		t.Errorf("Got unexpected sign string for AppTx. Expected:\n%v\nGot:\n%v", expected, signBytesHex)
 	}
 }