diff --git a/lib/TransactionBuilder.js b/lib/TransactionBuilder.js
index f4d5375..9b34376 100644
--- a/lib/TransactionBuilder.js
+++ b/lib/TransactionBuilder.js
@@ -65,6 +65,7 @@ var log = require('../util/log');
 var Transaction = require('./Transaction');
 
 var FEE_PER_1000B_SAT = parseInt(0.0001 * util.COIN);
+var TOOBJ_VERSION = 1;
 
 // Methods
 // -------
@@ -97,6 +98,14 @@ var FEE_PER_1000B_SAT = parseInt(0.0001 * util.COIN);
 
 function TransactionBuilder(opts) {
   opts = opts || {};
+
+  this.vanilla = {};
+  this.vanilla.scriptSig = [];
+  this.vanilla.opts = JSON.stringify(opts);
+
+  // If any default opts is changed, TOOBJ_VERSION should be changed as
+  // a caution measure.
+ 
   this.lockTime = opts.lockTime || 0;
   this.spendUnconfirmed = opts.spendUnconfirmed || false;
 
@@ -108,7 +117,6 @@ function TransactionBuilder(opts) {
 
   this.tx = {};
   this.inputsSigned = 0;
-  this.signaturesAdded = 0;
 
   return this;
 }
@@ -177,6 +185,7 @@ TransactionBuilder.infoForP2sh = function(opts, networkName) {
 //   That amount is in BTCs (as returned in insight and bitcoind).
 //   amountSat (instead of amount) can be given to provide amount in satochis.
 TransactionBuilder.prototype.setUnspent = function(unspent) {
+  this.vanilla.utxos = JSON.stringify(unspent);
   this.utxos = unspent;
   return this;
 };
@@ -381,8 +390,9 @@ TransactionBuilder.prototype._setFeeAndRemainder = function(txobj) {
 //
 
 TransactionBuilder.prototype.setOutputs = function(outs) {
-  var valueOutSat = bignum(0);
+  this.vanilla.outs = JSON.stringify(outs);
 
+  var valueOutSat = bignum(0);
   var txobj = {};
   txobj.version = 1;
   txobj.lock_time = this.lockTime || 0;
@@ -454,7 +464,7 @@ TransactionBuilder._signHashAndVerify = function(wk, txSigHash) {
 };
 
 TransactionBuilder.prototype._checkTx = function() {
-  if (!this.tx || !this.tx.ins.length || !this.tx.outs.length)
+  if (!this.tx ||  !this.tx.ins || !this.tx.ins.length || !this.tx.outs.length)
     throw new Error('tx is not defined');
 };
 
@@ -746,6 +756,9 @@ fnToSign[Script.TX_SCRIPTHASH] = TransactionBuilder.prototype._signScriptHash;
 //
 //
 TransactionBuilder.prototype.sign = function(keys) {
+  if (! (keys instanceof Array))
+    throw new Error('parameter should be an array');
+
   this._checkTx();
   var tx = this.tx,
     ins = tx.ins,
@@ -760,9 +773,10 @@ TransactionBuilder.prototype.sign = function(keys) {
 
     var ret = fnToSign[input.scriptType].call(this, walletKeyMap, input, txSigHash);
     if (ret && ret.script) {
+      this.vanilla.scriptSig[i] = ret.script.toString('hex');
+
       tx.ins[i].s = ret.script;
       if (ret.inputFullySigned) this.inputsSigned++;
-      if (ret.signaturesAdded) this.signaturesAdded += ret.signaturesAdded;
     }
   }
   return this;
@@ -775,6 +789,8 @@ TransactionBuilder.prototype.sign = function(keys) {
 // for generate the input for this call.
 //
 TransactionBuilder.prototype.setHashToScriptMap = function(hashToScriptMap) {
+  this.vanilla.hashToScriptMap = JSON.stringify(hashToScriptMap);
+
   this.hashToScriptMap = hashToScriptMap;
   return this;
 };
@@ -783,8 +799,6 @@ TransactionBuilder.prototype.setHashToScriptMap = function(hashToScriptMap) {
 // isFullySigned
 // -------------
 // Checks if the transaction have all the necesary signatures.
-// Also, `.signaturesAdded` and `.inputsSigned` can be queried
-// for more information about the transaction signature status.
 //
 TransactionBuilder.prototype.isFullySigned = function() {
   return this.inputsSigned === this.tx.ins.length;
@@ -803,25 +817,18 @@ TransactionBuilder.prototype.build = function() {
 // See `.fromObj`
 //
 TransactionBuilder.prototype.toObj = function() {
-  var data = {
-    valueInSat: this.valueInSat.toString(),
-    valueOutSat: this.valueOutSat.toString(),
-    feeSat: this.feeSat.toString(),
-    remainderSat: this.remainderSat.toString(),
 
-    hashToScriptMap: this.hashToScriptMap,
-    selectedUtxos: this.selectedUtxos,
-
-    inputsSigned: this.inputsSigned,
-    signaturesAdded: this.signaturesAdded,
-
-    signhash: this.signhash,
-    spendUnconfirmed: this.spendUnconfirmed,
+  var ret = {
+    version: TOOBJ_VERSION,
+    outs: JSON.parse(this.vanilla.outs),
+    utxos: JSON.parse(this.vanilla.utxos),
+    opts: JSON.parse(this.vanilla.opts),
+    scriptSig: this.vanilla.scriptSig,
   };
-  if (this.tx) {
-    data.tx = this.tx.serialize().toString('hex');
-  }
-  return data;
+  if (this.vanilla.hashToScriptMap)
+    ret.hashToScriptMap = JSON.parse(this.vanilla.hashToScriptMap);
+
+  return ret;
 };
 
 // fromObj
@@ -831,90 +838,36 @@ TransactionBuilder.prototype.toObj = function() {
 // with `.toObj`. See `.toObj`.
 
 TransactionBuilder.fromObj = function(data) {
-  var b = new TransactionBuilder();
-  b.valueInSat = data.valueInSat.toString();
-  b.valueOutSat = data.valueOutSat.toString();
-  b.feeSat = data.feeSat.toString();
-  b.remainderSat = data.remainderSat.toString();
 
-  b.hashToScriptMap = data.hashToScriptMap;
-  b.selectedUtxos = data.selectedUtxos;
+  if (data.version !== TOOBJ_VERSION)
+    throw new Error('Incompatible version at TransactionBuilder fromObj');
 
-  b.inputsSigned = data.inputsSigned;
-  b.signaturesAdded = data.signaturesAdded;
+  var b = new TransactionBuilder(data.opts);
+  if (data.utxos) {
+    b.setUnspent(data.utxos); 
 
-  b.signhash = data.signhash;
-  b.spendUnconfirmed = data.spendUnconfirmed;
+    if (data.hashToScriptMap)
+      b.setHashToScriptMap(data.hashToScriptMap);
 
-  b._setInputMap();
+    if (data.outs) {
+      b.setOutputs(data.outs);
 
-  if (data.tx) {
-    // Tx may have signatures, that are not on txobj
-    var t = new Transaction();
-    t.parse(new Buffer(data.tx, 'hex'));
-    b.tx = t;
+      for (var i in data.scriptSig) {
+        b.tx.ins[i].s = new Buffer(data.scriptSig[i], 'hex');
+
+        var scriptSig = new Script(b.tx.ins[i].s);
+        if ( scriptSig.finishedMultiSig() !== false )
+          b.inputsSigned++;
+      }
+    }
   }
   return b;
 };
 
 
 TransactionBuilder.prototype._checkMergeability = function(b) {
-  var self = this;
-
-  // Builder should have the same params
-  ['valueInSat', 'valueOutSat', 'feeSat', 'remainderSat', 'signhash', 'spendUnconfirmed']
-    .forEach(function(k) {
-
-      if (self[k].toString() !== b[k].toString()) {
-        throw new Error('mismatch at TransactionBuilder match: ' + k + ': ' + self[k] + ' vs. ' + b[k]);
-      }
-    });
-
-  if (self.hashToScriptMap) {
-    var err = 0;
-    if (!b.hashToScriptMap) err = 1;
-    Object.keys(self.hashToScriptMap).forEach(function(k) {
-      if (!b.hashToScriptMap[k]) err = 1;
-      if (self.hashToScriptMap[k] !== b.hashToScriptMap[k]) err = 1;
-    });
-    if (err)
-      throw new Error('mismatch at TransactionBuilder hashToScriptMap');
-  }
-
-
-  var err = 0,
-    i = 0;;
-  self.selectedUtxos.forEach(function(u) {
-    if (!err) {
-      var v = b.selectedUtxos[i++];
-      if (!v) err = 1;
-      // confirmations could differ
-      ['address', 'hash', 'scriptPubKey', 'vout', 'amount'].forEach(function(k) {
-        if (u[k] !== v[k])
-          err = k;
-      });
-    }
-  });
-  if (err)
-    throw new Error('mismatch at TransactionBuilder selectedUtxos #' + i - 1 + ' Key:' + err);
-
-
-  err = 0;
-  i = 0;;
-  self.inputMap.forEach(function(u) {
-    if (!err) {
-      var v = b.inputMap[i++];
-      if (!v) err = 1;
-      // confirmations could differ
-      ['address', 'scriptType', 'scriptPubKey', 'i'].forEach(function(k) {
-        if (u[k].toString() !== v[k].toString())
-          err = k;
-      });
-    }
-  });
-  if (err)
-    throw new Error('mismatch at TransactionBuilder inputMap #' + i - 1 + ' Key:' + err);
-
+  if ( JSON.stringify(this.vanilla) !==  JSON.stringify(this.vanilla))
+    throw new Error('cannot merge: incompatible builders')
 };
 
 // TODO this could be on Script class
@@ -944,22 +897,33 @@ TransactionBuilder.prototype._mergeInputSigP2sh = function(input, s0, s1) {
     }
   }
 
+console.log('[TransactionBuilder.js.887:diff:]',diff); //TODO
   // Add signatures
   for (var j in diff) {
     var newSig = diff[j];
     var order = this._getNewSignatureOrder(newSig.prio, s0, p2sh.txSigHash, pubkeys);
+
+    if (this._getSighashType(newSig.chunk) !== this.signhash)
+      throw new Error('signhash type mismatch at merge');
+
     s0.chunks.splice(order + 1, 0, newSig.chunk);
-    this.signaturesAdded++;
   }
   s0.updateBuffer();
   return s0.getBuffer();
 };
 
+
+// TODO: move this to script
+TransactionBuilder.prototype._getSighashType = function(sig) {
+  return sig[sig.length-1];
+};
+
 // TODO this could be on Script class
 TransactionBuilder.prototype._mergeInputSig = function(index, s0buf, s1buf) {
   if (buffertools.compare(s0buf, s1buf) === 0)
     return s0buf;
 
+console.log('[TransactionBuilder.js.925]'); //TODO
   var s0 = new Script(s0buf);
   var s1 = new Script(s1buf);
   var l0 = s0.chunks.length;
@@ -969,15 +933,25 @@ TransactionBuilder.prototype._mergeInputSig = function(index, s0buf, s1buf) {
   if (l0 && l1 && ((l0 < 2 && l1 > 2) || (l1 < 2 && l0 > 2)))
     throw new Error('TX sig types mismatch in merge');
 
+console.log('[TransactionBuilder.js.935]', l0, l1); //TODO
   if ((!l0 && !l1) || (l0 && !l1) || (!l0 && l1))
     return s1buf;
 
+
+console.log('[TransactionBuilder.js.940]'); //TODO
+
   // Get the pubkeys
   var input = this.inputMap[index];
   var type = input.scriptPubKey.classify();
 
+console.log('[TransactionBuilder.js.941]'); //TODO
   //p2pubkey or p2pubkeyhash
   if (type === Script.TX_PUBKEYHASH || type === Script.TX_PUBKEY) {
+    var s = new Script(s1buf);
+
+    if (this._getSighashType(s.chunks[0]) !== this.signhash)
+      throw new Error('signhash type mismatch at merge');
+
     log.debug('Merging two signed inputs type:' +
       input.scriptPubKey.getRawOutType() + '. Signatures differs. Using the first version.');
     return s0buf;
@@ -985,6 +959,9 @@ TransactionBuilder.prototype._mergeInputSig = function(index, s0buf, s1buf) {
     // No support for normal multisig or strange txs.
     throw new Error('Script type:' + input.scriptPubKey.getRawOutType() + 'not supported at #merge');
   }
+
+console.log('[TransactionBuilder.js.957]'); //TODO
+
   return this._mergeInputSigP2sh(input, s0, s1);
 };
 
@@ -992,6 +969,7 @@ TransactionBuilder.prototype._mergeInputSig = function(index, s0buf, s1buf) {
 TransactionBuilder.prototype._mergeTx = function(tx) {
   var v0 = this.tx;
   var v1 = tx;
+console.log('[TransactionBuilder.js.966:var:]'); //TODO
 
   var l = v0.ins.length;
   if (l !== v1.ins.length)
@@ -999,6 +977,7 @@ TransactionBuilder.prototype._mergeTx = function(tx) {
 
   this.inputsSigned = 0;
   for (var i = 0; i < l; i++) {
+console.log('[TransactionBuilder.js.974:for:]',i); //TODO
     var i0 = v0.ins[i];
     var i1 = v1.ins[i];
 
@@ -1008,18 +987,31 @@ TransactionBuilder.prototype._mergeTx = function(tx) {
     if (buffertools.compare(i0.o, i1.o) !== 0)
       throw new Error('TX .o in mismatch in merge. Input:', i);
 
+console.log('[TransactionBuilder.js.984]'); //TODO
     i0.s = this._mergeInputSig(i, i0.s, i1.s);
+    this.vanilla.scriptSig[i]= i0.s.toString('hex');
 
     if (v0.isInputComplete(i)) this.inputsSigned++;
   }
 };
 
+// clone
+// -----
+// Clone current TransactionBuilder, regenerate derived fields.
+//
+TransactionBuilder.prototype.clone = function() {
+  return new TransactionBuilder.fromObj(this.toObj());
+};
+
 // merge
 // -----
 // Merge to TransactionBuilder objects, merging inputs signatures.
 // This function supports multisig p2sh inputs.
 
-TransactionBuilder.prototype.merge = function(b) {
+TransactionBuilder.prototype.merge = function(inB) {
+  // 
+  var b = inB.clone();
+
   this._checkMergeability(b);
 
   // Does this tX have any signature already?
diff --git a/test/test.TransactionBuilder.js b/test/test.TransactionBuilder.js
index 9db3616..e7f88d4 100644
--- a/test/test.TransactionBuilder.js
+++ b/test/test.TransactionBuilder.js
@@ -218,11 +218,12 @@ describe('TransactionBuilder', function() {
 
 
 
-  var getBuilder3 = function (outs) {
+  var getBuilder3 = function (outs, signhash) {
 
     var opts = {
       remainderOut: {address: 'mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd'},
       spendUnconfirmed: true,
+      signhash: signhash,
     };
 
     var outs = outs || [{
@@ -693,11 +694,11 @@ describe('TransactionBuilder', function() {
 //     "redeemScript" : "532103197599f6e209cefef07da2fddc6fe47715a70162c531ffff8e611cef23dfb70d210380a29968851f93af55e581c43d9ef9294577a439a3ca9fc2bc47d1ca2b3e9127210392dccb2ed470a45984811d6402fdca613c175f8f3e4eb8e2306e8ccd7d0aed032103a94351fecc4328bb683bf93a1aa67378374904eac5980c7966723a51897c56e32103e085eb6fa1f20b2722c16161144314070a2c316a9cae2489fd52ce5f63fff6e455ae"
 // }
 //
-  var getP2shBuilder = function(setMap) {
+  var getP2shBuilder = function(setMap, opts) {
     var network = 'testnet';
-    var opts = {
-      remainderOut: {address: 'mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd'},
-    };
+    opts = opts || {};
+    opts.remainderOut = opts.remainderOut || {address: 'mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd'};
+
     var data = getInfoForP2sh();
     // multisig p2sh
     var p2shOpts = {nreq:3, pubkeys:data.pubkeys};
@@ -760,43 +761,36 @@ describe('TransactionBuilder', function() {
     var k2 = testdata.dataUnspentSign.keyStringsP2sh.slice(1,2);
     var k5 = testdata.dataUnspentSign.keyStringsP2sh.slice(4,5);
     b.isFullySigned().should.equal(false);
-    b.signaturesAdded.should.equal(0);
 
     b.sign(k1);
     b.isFullySigned().should.equal(false);
-    b.signaturesAdded.should.equal(1);
 
     var tx = b.build();
     tx.ins.length.should.equal(1);
     tx.outs.length.should.equal(2);
     tx.isComplete().should.equal(false);
-    b.signaturesAdded.should.equal(1);
 
     // Sign with the same
     b.sign(k1);
     b.isFullySigned().should.equal(false);
     tx.isComplete().should.equal(false);
-    b.signaturesAdded.should.equal(1);
 
     // Sign with k5
     b.sign(k5);
 ///
     b.isFullySigned().should.equal(false);
     tx.isComplete().should.equal(false);
-    b.signaturesAdded.should.equal(2);
 
     // Sign with same
     b.sign(k5);
     b.isFullySigned().should.equal(false);
     tx.isComplete().should.equal(false);
-    b.signaturesAdded.should.equal(2);
 
 
     // Sign k2
     b.sign(k2);
     b.isFullySigned().should.equal(true);
     tx.isComplete().should.equal(true);
-    b.signaturesAdded.should.equal(3);
   });
 
   it('should sign a p2sh/p2pubkeyhash tx', function() {
@@ -844,190 +838,311 @@ describe('TransactionBuilder', function() {
     tx.isComplete().should.equal(true);
   });
 
-  it('#toObj #fromObj roundtrip', function() {
-    var b = getBuilder2();
 
-    b.isFullySigned().should.equal(false);
-    b.getSelectedUnspent().length.should.equal(2);
-
-    var data =b.toObj();
-
-    var b2 = TransactionBuilder.fromObj(data);
-    var tx = b2.build();
-    should.exist(tx);
-    tx.version.should.equal(1);
-    tx.ins.length.should.equal(2);
-    tx.outs.length.should.equal(2);
-
-    util.valueToBigInt(tx.outs[0].v).cmp(8000000).should.equal(0);
-
-    // remainder is 0.0299 here because unspent select utxos in order
-    util.valueToBigInt(tx.outs[1].v).cmp(2990000).should.equal(0);
-  });
-
-  it('#toObj #fromObj roundtrip, step signatures p2sh/p2pubkeyhash', function() {
+  it('should check sign parameters', function() {
     var b = getP2shBuilder(1);     
-
-    var k1 = testdata.dataUnspentSign.keyStringsP2sh.slice(0,1);
-    var k2 = testdata.dataUnspentSign.keyStringsP2sh.slice(1,2);
-    var k5 = testdata.dataUnspentSign.keyStringsP2sh.slice(4,5);
-    b.isFullySigned().should.equal(false);
-    b.signaturesAdded.should.equal(0);
-
-    var b2 = TransactionBuilder.fromObj(b.toObj());
-
-    b2.sign(k1);
-
-    b2.isFullySigned().should.equal(false);
-    b2.signaturesAdded.should.equal(1);
-
-    var tx = b2.build();
-    tx.ins.length.should.equal(1);
-    tx.outs.length.should.equal(2);
-    tx.isComplete().should.equal(false);
-    b2.signaturesAdded.should.equal(1);
-
-    // Sign with the same
-    var b3 = TransactionBuilder.fromObj(b2.toObj());
-
-    b3.sign(k1);
-    b3.isFullySigned().should.equal(false);
-    b3.signaturesAdded.should.equal(1);
-
-    // Sign with k5
-    var b4 = TransactionBuilder.fromObj(b3.toObj());
-    b4.sign(k5);
-    b4.isFullySigned().should.equal(false);
-    b4.signaturesAdded.should.equal(2);
-
-    var b5 = TransactionBuilder.fromObj(b4.toObj());
-    // Sign k2
-    b5.sign(k2);
-    b5.isFullySigned().should.equal(true);
-    var tx2 = b5.build();
-    tx2.isComplete().should.equal(true);
-    b5.signaturesAdded.should.equal(3);
+    (function() { b.sign(testdata.dataUnspentSign.keyStringsP2sh[0]) }).should.throw('array');
   });
 
-  it('#merge self', function() {
-    var b = getBuilder3([{
-      address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
-      amount: 16
-    }])
-      .sign(testdata.dataUnspentSign.keyStrings);
-    b.merge(b);
 
-    b.isFullySigned().should.equal(true);
-    var tx = b.build();
-    tx.isComplete().should.equal(true);
-    tx.ins.length.should.equal(3);
-    tx.outs.length.should.equal(2);
-  });
-  it('#merge simple', function() {
-    var b = getBuilder3([{
-      address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
-      amount: 16
-    }])
-      .sign(testdata.dataUnspentSign.keyStrings);
+  describe('serizalization', function(){
 
-    // merge simple
-    var b2 = getBuilder3([{
-      address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
-      amount: 16
-    }]);
-    b2.isFullySigned().should.equal(false);
-    b2.merge(b);
+    it('#toObj #fromObj roundtrip', function() {
+      var b = getBuilder2();
 
-    b2.isFullySigned().should.equal(true);
-    var tx = b.build();
-    tx.isComplete().should.equal(true);
-    tx.ins.length.should.equal(3);
-    tx.outs.length.should.equal(2);
-  });
+      b.isFullySigned().should.equal(false);
+      b.getSelectedUnspent().length.should.equal(2);
 
-  it('#merge checks', function() {
-    var b = getBuilder3([{
-      address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
-      amount: 16
-    }]);
-    // bad amount
-    var b2 = getBuilder3([{
-      address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
-      amount: 15
-    }]);
-    (function() {b2.merge(b);}).should.throw();
-    // bad out
-    b2 = getBuilder3([{
-      address: 'muHct3YZ9Nd5Pq7uLYYhXRAxeW4EnpcaLz',
-      amount: 16
-    }]);
-    (function() {b2.merge(b);}).should.throw();
+      var data =b.toObj();
 
-    // same signature 
-    //  -> this fails: no way to check signatures, since PRIV Keys are not stored
-    b = getBuilder3([{
-      address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
-      amount: 16
-    }])
-      .sign(testdata.dataUnspentSign.keyStrings);
-    // merge simple
-    b2 = getBuilder3([{
-      address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
-      amount: 16
-    }])
-      .sign(testdata.dataUnspentSign.keyStrings);
-    b2.isFullySigned().should.equal(true);
-    b2.merge(b);
-    b2.isFullySigned().should.equal(true);
-  });
+      var b2 = TransactionBuilder.fromObj(data);
+      var tx = b2.build();
+      should.exist(tx);
+      tx.version.should.equal(1);
+      tx.ins.length.should.equal(2);
+      tx.outs.length.should.equal(2);
 
-  it('#merge p2sh/steps', function(done) {
-    var b = getP2shBuilder(1);     
-    var k1 = testdata.dataUnspentSign.keyStringsP2sh.slice(0,1);
-    var k2 = testdata.dataUnspentSign.keyStringsP2sh.slice(1,2);
-    var k3 = testdata.dataUnspentSign.keyStringsP2sh.slice(2,3);
-    b.isFullySigned().should.equal(false);
-    b.signaturesAdded.should.equal(0);
-    b.sign(k1);
-    b.signaturesAdded.should.equal(1);
-    b.isFullySigned().should.equal(false);
-    var tx = b.build();
-    tx.isComplete().should.equal(false);
+      util.valueToBigInt(tx.outs[0].v).cmp(8000000).should.equal(0);
 
-    b = TransactionBuilder.fromObj(b.toObj());
-
-    // TODO TO OBJ!
-    var b2 = getP2shBuilder(1); 
-    b2.sign(k2);
-    b2.signaturesAdded.should.equal(1);
-    b2.merge(b);
-    b2.signaturesAdded.should.equal(2);
-    tx = b2.build();
-    tx.isComplete().should.equal(false);
-
-    b2 = TransactionBuilder.fromObj(b2.toObj());
-    var b3 = getP2shBuilder(1); 
-    b3.sign(k3);
-    b3.signaturesAdded.should.equal(1);
-    b3.merge(b2);
-    b3.signaturesAdded.should.equal(3);
-    tx = b3.build();
-    tx.isComplete().should.equal(true);
-
-    b3 = TransactionBuilder.fromObj(b3.toObj());
-    b2.merge(b3);
-    b2.signaturesAdded.should.equal(3);
-    tx = b2.build();
-    tx.isComplete().should.equal(true);
-
-    var shex = testdata.dataUnspentSign.unspentP2sh[0].scriptPubKey;
-    var s    = new Script(new Buffer(shex,'hex'));
-    tx.verifyInput(0,s, vopts, function(err, results){
-      should.exist(results);
-      results.should.equal(true);
-      should.not.exist(err);
-      done();
+      // remainder is 0.0299 here because unspent select utxos in order
+      util.valueToBigInt(tx.outs[1].v).cmp(2990000).should.equal(0);
     });
 
+    it('#toObj #fromObj roundtrip, step signatures p2sh/p2pubkeyhash', function() {
+      var b = getP2shBuilder(1);     
+
+      var keys = JSON.parse(JSON.stringify(testdata.dataUnspentSign.keyStringsP2sh));
+
+      var k1 = keys.slice(0,1);
+      var k2 = keys.slice(1,2);
+      var k5 = keys.slice(4,5);
+      b.isFullySigned().should.equal(false);
+
+      var b2 = TransactionBuilder.fromObj(b.toObj());
+
+      b2.sign(k1);
+      b2.isFullySigned().should.equal(false);
+
+      var tx = b2.build();
+      tx.ins.length.should.equal(1);
+      tx.outs.length.should.equal(2);
+      tx.isComplete().should.equal(false);
+
+      // Sign with the same
+      var b3 = TransactionBuilder.fromObj(b2.toObj());
+
+      b3.sign(k1);
+      b3.isFullySigned().should.equal(false);
+
+      // Sign with k5
+      var b4 = TransactionBuilder.fromObj(b3.toObj());
+      b4.sign(k5);
+      b4.isFullySigned().should.equal(false);
+
+      var b5 = TransactionBuilder.fromObj(b4.toObj());
+      // Sign k2
+      b5.sign(k2);
+      b5.isFullySigned().should.equal(true);
+      var tx2 = b5.build();
+      tx2.isComplete().should.equal(true);
+    });
+
+
+    it('should keep signatures after clone', function() {
+      var k1 = testdata.dataUnspentSign.keyStringsP2sh[0];
+      var k2 = testdata.dataUnspentSign.keyStringsP2sh[1];
+
+      var b = getP2shBuilder(1);     
+      var b2 = getP2shBuilder(1); 
+
+      b.sign([k1]);
+      b2.sign([k2]);
+      b2.merge(b);
+      var tx2 = b2.build();
+      tx2.countInputSignatures(0).should.equal(2, 'before clone');
+      tx2 = b2.clone().build();
+      tx2.countInputSignatures(0).should.equal(2, 'after clone');
+
+    });
+  });
+
+
+  describe('#merge', function() {
+    it('with self', function() {
+      var b = getBuilder3([{
+        address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
+        amount: 16
+      }])
+        .sign(testdata.dataUnspentSign.keyStrings);
+      b.merge(b);
+
+      b.isFullySigned().should.equal(true);
+      var tx = b.build();
+      tx.isComplete().should.equal(true);
+      tx.ins.length.should.equal(3);
+      tx.outs.length.should.equal(2);
+    });
+
+    it('#merge simple', function() {
+      var b = getBuilder3([{
+        address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
+        amount: 16
+      }])
+        .sign(testdata.dataUnspentSign.keyStrings);
+
+      // merge simple
+      var b2 = getBuilder3([{
+        address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
+        amount: 16
+      }]);
+      b2.isFullySigned().should.equal(false);
+      b2.merge(b);
+
+      b2.isFullySigned().should.equal(true);
+      var tx = b.build();
+      tx.isComplete().should.equal(true);
+      tx.ins.length.should.equal(3);
+      tx.outs.length.should.equal(2);
+    });
+
+
+    var b = getBuilder3([{
+      address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
+      amount: 16
+    }]);
+
+    it('should check amount', function() {
+      // bad amount
+      var b2 = getBuilder3([{
+        address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
+        amount: 15
+      }]);
+      (function() {b2.merge(b);}).should.throw('NTXID');
+    });
+    it('should check addresses', function() {
+      // bad out
+      var b2 = getBuilder3([{
+        address: 'muHct3YZ9Nd5Pq7uLYYhXRAxeW4EnpcaLz',
+        amount: 16
+      }]);
+      (function() {b2.merge(b);}).should.throw('NTXID');
+    });
+
+
+    it('should check signhash in p2pubkeyhash', function() {
+      // bad amount
+      var b = getBuilder3([{
+        address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
+        amount: 15
+      }]);
+      b.sign(testdata.dataUnspentSign.keyStrings);
+
+      var b2 = getBuilder3([{
+        address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
+        amount: 15
+      }],  bitcore.Transaction.SIGHASH_NONE);
+      b2.sign(testdata.dataUnspentSign.keyStrings);
+
+      (function() {b2.merge(b);}).should.throw('signhash');
+    });
+
+
+    it('should merge signed signed txs', function() {
+      // same signature 
+      //  -> keep first signature
+      var b = getBuilder3([{
+        address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
+        amount: 16
+      }])
+        .sign(testdata.dataUnspentSign.keyStrings);
+      // merge simple
+      var b2 = getBuilder3([{
+        address: 'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE',
+        amount: 16
+      }])
+        .sign(testdata.dataUnspentSign.keyStrings);
+      b2.isFullySigned().should.equal(true);
+      b2.merge(b);
+      b2.isFullySigned().should.equal(true);
+    });
+ 
+
+    it('#merge p2sh in 2 steps', function() {
+      var b = getP2shBuilder(1);     
+      var b2 = getP2shBuilder(1);     
+      var k1 = testdata.dataUnspentSign.keyStringsP2sh[0];
+      var k2 = testdata.dataUnspentSign.keyStringsP2sh[1];
+      b.sign([k1]);
+      b2.sign([k2]);
+      b.merge(b2);
+      var tx = b.build();
+      tx.countInputSignatures(0).should.equal(2);
+    });
+
+    it('#merge p2sh in 2 steps, case 2', function() {
+      var b = getP2shBuilder(1);     
+      var b2 = getP2shBuilder(1);     
+      var k1 = testdata.dataUnspentSign.keyStringsP2sh[0];
+      var k2 = testdata.dataUnspentSign.keyStringsP2sh[1];
+      var k3 = testdata.dataUnspentSign.keyStringsP2sh[2];
+      b.sign([k1,k2]);
+      b2.sign([k3]);
+      b.merge(b2);
+      var tx = b.build();
+      tx.countInputSignatures(0).should.equal(3);
+    });
+
+
+    it('#merge p2sh sign twice', function() {
+      var k1 = testdata.dataUnspentSign.keyStringsP2sh[0];
+      var k2 = testdata.dataUnspentSign.keyStringsP2sh[1];
+
+      var b = getP2shBuilder(1);     
+      var b2 = getP2shBuilder(1); 
+
+      b.sign([k1]);
+      b2.sign([k1,k2]);
+      b2.merge(b);
+      var tx = b2.build();
+      tx.countInputSignatures(0).should.equal(2);
+    });
+
+
+    it('#merge p2sh sign twice, case2', function() {
+      var k1 = testdata.dataUnspentSign.keyStringsP2sh[0];
+      var k2 = testdata.dataUnspentSign.keyStringsP2sh[1];
+
+      var b = getP2shBuilder(1);     
+      var b2 = getP2shBuilder(1); 
+
+      b.sign([k1]);
+      b2.sign([k1]);
+      b2.merge(b);
+      var tx = b2.build();
+      tx.countInputSignatures(0).should.equal(1);
+    });
+
+
+
+
+
+    it('#merge p2sh in 3 steps', function() {
+      var k1 = testdata.dataUnspentSign.keyStringsP2sh[0];
+      var k2 = testdata.dataUnspentSign.keyStringsP2sh[1];
+      var k3 = testdata.dataUnspentSign.keyStringsP2sh[2];
+
+      var b = getP2shBuilder(1);     
+      var b2 = getP2shBuilder(1); 
+      var b3 = getP2shBuilder(1); 
+
+      b.sign([k1]);
+      b2.sign([k2]);
+      b2.merge(b);
+      var tx = b2.clone().build();
+      tx.countInputSignatures(0).should.equal(2);
+
+      b3.sign([k3]);
+      b3.merge(b2);
+      tx = b3.build();
+      tx.countInputSignatures(0).should.equal(3);
+    });
+
+
+    it.only('should check signhash in p2sh/merge', function() {
+      var b = getP2shBuilder(1);     
+      var k1 = testdata.dataUnspentSign.keyStringsP2sh.slice(0,1);
+      var k2 = testdata.dataUnspentSign.keyStringsP2sh.slice(1,2);
+      var k3 = testdata.dataUnspentSign.keyStringsP2sh.slice(2,3);
+      b.isFullySigned().should.equal(false);
+      b.sign(k1);
+      var tx = b.build();
+      tx.isComplete().should.equal(false);
+      b = TransactionBuilder.fromObj(b.toObj());
+
+      var b2 = getP2shBuilder(1, {signhash: bitcore.Transaction.SIGHASH_NONE }); 
+      b2.sign(k2);
+
+console.log('[test.TransactionBuilder.js.1124]'); //TODO
+      (function() { b2.merge(b)}).should.throw();
+    });
+
+    it('#merge p2sh/steps change return address', function() {
+      var b = getP2shBuilder(1);     
+      var k1 = testdata.dataUnspentSign.keyStringsP2sh.slice(0,1);
+      var k2 = testdata.dataUnspentSign.keyStringsP2sh.slice(1,2);
+      var k3 = testdata.dataUnspentSign.keyStringsP2sh.slice(2,3);
+      b.isFullySigned().should.equal(false);
+      b.sign(k1);
+      var tx = b.build();
+      tx.isComplete().should.equal(false);
+      b = TransactionBuilder.fromObj(b.toObj());
+
+      var b2 = getP2shBuilder(1, {remainderOut: {address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE' }}); 
+      b2.sign(k2);
+      (function() { b2.merge(b)}).should.throw('asdds');
+    });
+
+
+
   });
 });