diff --git a/lib/bcoin/block.js b/lib/bcoin/block.js
index f260631c..aefa636c 100644
--- a/lib/bcoin/block.js
+++ b/lib/bcoin/block.js
@@ -278,7 +278,9 @@ Block.prototype.inspect = function inspect() {
     version: this.version,
     prevBlock: utils.revHex(this.prevBlock),
     merkleRoot: utils.revHex(this.merkleRoot),
-    commitmentHash: this.commitmentHash ? utils.revHex(this.commitmentHash) : null,
+    commitmentHash: this.commitmentHash
+      ? utils.revHex(this.commitmentHash)
+      : null,
     ts: this.ts,
     bits: this.bits,
     nonce: this.nonce,
@@ -289,13 +291,12 @@ Block.prototype.inspect = function inspect() {
 
 Block.prototype.toJSON = function toJSON() {
   return {
-    type: this.type,
+    type: 'block',
     height: this.height,
     hash: utils.revHex(this.hash('hex')),
     version: this.version,
     prevBlock: utils.revHex(this.prevBlock),
     merkleRoot: utils.revHex(this.merkleRoot),
-    commitmentHash: this.commitmentHash ? utils.revHex(this.commitmentHash) : null,
     ts: this.ts,
     bits: this.bits,
     nonce: this.nonce,
@@ -307,6 +308,7 @@ Block.prototype.toJSON = function toJSON() {
 };
 
 Block._fromJSON = function _fromJSON(json) {
+  assert.equal(json.type, 'block');
   json.prevBlock = utils.revHex(json.prevBlock);
   json.merkleRoot = utils.revHex(json.merkleRoot);
   json.txs = json.txs.map(function(tx) {
@@ -321,7 +323,7 @@ Block.fromJSON = function fromJSON(json) {
 
 Block.prototype.toCompact = function toCompact() {
   return {
-    type: this.type,
+    type: 'block',
     hash: this.hash('hex'),
     prevBlock: this.prevBlock,
     ts: this.ts,
diff --git a/lib/bcoin/mtx.js b/lib/bcoin/mtx.js
index bae049f5..101cf448 100644
--- a/lib/bcoin/mtx.js
+++ b/lib/bcoin/mtx.js
@@ -62,20 +62,7 @@ function MTX(options) {
 utils.inherits(MTX, bcoin.tx);
 
 MTX.prototype.clone = function clone() {
-  var tx = new MTX(this);
-
-  tx.inputs = tx.inputs.map(function(input) {
-    input.script = input.script.slice();
-    input.witness = input.witness.slice();
-    return input;
-  });
-
-  tx.outputs = tx.outputs.map(function(output) {
-    output.script = output.script.slice();
-    return output;
-  });
-
-  return tx;
+  return new MTX(this);
 };
 
 MTX.prototype.hash = function hash(enc) {
@@ -152,6 +139,12 @@ MTX.prototype.addInput = function addInput(options, index) {
 
   input = bcoin.input(options, this);
 
+  if (options.script)
+    input.script = options.script.slice();
+
+  if (options.witness)
+    input.witness = options.witness.slice();
+
   this.inputs.push(input);
 
   return this;
@@ -579,6 +572,9 @@ MTX.prototype.addOutput = function addOutput(obj, value) {
 
   this.outputs.push(output);
 
+  if (options.script)
+    output.script = options.script.slice();
+
   this.scriptOutput(this.outputs.length - 1, options);
 
   return this;
@@ -1078,7 +1074,7 @@ MTX.prototype.increaseFee = function increaseFee(unspent, address, fee) {
 
 MTX.prototype.toCompact = function toCompact(coins) {
   return {
-    type: 'tx',
+    type: 'mtx',
     block: this.block,
     height: this.height,
     ts: this.ts,
@@ -1094,7 +1090,7 @@ MTX.prototype.toCompact = function toCompact(coins) {
 MTX._fromCompact = function _fromCompact(json) {
   var raw, data, tx;
 
-  assert.equal(json.type, 'tx');
+  assert.equal(json.type, 'mtx');
 
   raw = new Buffer(json.tx, 'hex');
   data = bcoin.protocol.parser.parseTX(raw);
@@ -1143,6 +1139,7 @@ MTX.prototype.toJSON = function toJSON() {
 };
 
 MTX._fromJSON = function fromJSON(json) {
+  assert.equal(json.type, 'mtx');
   return {
     block: json.block ? utils.revHex(json.block) : null,
     height: json.height,
@@ -1185,43 +1182,11 @@ MTX.fromRaw = function fromRaw(data, enc) {
 };
 
 MTX.fromTX = function fromTX(tx) {
-  var mtx = new bcoin.tx({
-    ts: tx.ts,
-    ps: tx.ps,
-    block: tx.block,
-    height: tx.height,
-    version: tx.version,
-    inputs: tx.inputs.map(function(input) {
-      input.script = input.script.slice();
-      return input;
-    }),
-    outputs: tx.outputs.map(function(output) {
-      output.script = output.script.slice();
-      return output;
-    }),
-    locktime: tx.locktime
-  });
-  return mtx;
+  return new MTX(tx);
 };
 
 MTX.prototype.toTX = function toTX() {
-  var tx = new bcoin.tx({
-    ts: this.ts,
-    ps: this.ps,
-    block: this.block,
-    height: this.height,
-    version: this.version,
-    inputs: this.inputs.map(function(input) {
-      input.script = input.script.slice();
-      return input;
-    }),
-    outputs: this.outputs.map(function(output) {
-      output.script = output.script.slice();
-      return output;
-    }),
-    locktime: this.locktime
-  });
-  return tx;
+  return new bcoin.tx(this);
 };
 
 /**
diff --git a/lib/bcoin/tx.js b/lib/bcoin/tx.js
index c16ee965..b04bd35e 100644
--- a/lib/bcoin/tx.js
+++ b/lib/bcoin/tx.js
@@ -71,17 +71,6 @@ TX.prototype.setBlock = function setBlock(block, index) {
   this.index = index;
 };
 
-TX.prototype.clone = function clone() {
-  var tx = new TX(this);
-  delete tx._raw;
-  delete tx._size;
-  delete tx._offset;
-  delete tx._hash;
-  delete tx._whash;
-  delete tx._witnessSize;
-  return tx;
-};
-
 TX.prototype.hash = function hash(enc) {
   if (!this._hash)
     this._hash = utils.dsha256(this.renderNormal());
@@ -955,6 +944,7 @@ TX.prototype.inspect = function inspect() {
     date: new Date(this.ts * 1000).toISOString(),
     block: this.block ? utils.revHex(this.block) : null,
     ts: this.ts,
+    index: this.index,
     version: this.version,
     inputs: this.inputs,
     outputs: this.outputs,
@@ -1004,12 +994,13 @@ TX.fromCompact = function fromCompact(json) {
 
 TX.prototype.toJSON = function toJSON() {
   return {
-    type: this.type,
+    type: 'tx',
     hash: utils.revHex(this.hash('hex')),
     witnessHash: utils.revHex(this.witnessHash('hex')),
     height: this.height,
     block: this.block ? utils.revHex(this.block) : null,
     ts: this.ts,
+    index: this.index,
     version: this.version,
     inputs: this.inputs.map(function(input) {
       return input.toJSON();
@@ -1022,10 +1013,12 @@ TX.prototype.toJSON = function toJSON() {
 };
 
 TX._fromJSON = function fromJSON(json) {
+  assert.equal(json.type, 'tx');
   return {
     block: json.block ? utils.revHex(json.block) : null,
     height: json.height,
     ts: json.ts,
+    index: json.index,
     version: json.version,
     inputs: json.inputs.map(function(input) {
       return bcoin.input._fromJSON(input);