diff --git a/Makefile b/Makefile
index f0d4d487..cc51981c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,7 @@
 all:
 	@npm run browserify
 	@npm run uglify
+	@cp -f lib/workers/worker-browser.js browser/bcoin-worker.js
 
 clean:
 	@npm run clean
diff --git a/browser/server.js b/browser/server.js
index 2e786213..2cfaaa2a 100644
--- a/browser/server.js
+++ b/browser/server.js
@@ -17,7 +17,8 @@ proxy.on('error', function(err) {
 var index = fs.readFileSync(__dirname + '/index.html');
 var indexjs = fs.readFileSync(__dirname + '/index.js');
 var bcoin = fs.readFileSync(__dirname + '/bcoin.js');
-var worker = fs.readFileSync(__dirname + '/../lib/workers/worker-browser.js');
+var master = fs.readFileSync(__dirname + '/bcoin-master.js');
+var worker = fs.readFileSync(__dirname + '/bcoin-worker.js');
 
 server.get('/favicon.ico', function(req, res, send, next) {
   send(404, '', 'text');
@@ -35,6 +36,10 @@ server.get('/bcoin.js', function(req, res, send, next) {
   send(200, bcoin, 'js');
 });
 
+server.get('/bcoin-master.js', function(req, res, send, next) {
+  send(200, master, 'js');
+});
+
 server.get('/bcoin-worker.js', function(req, res, send, next) {
   send(200, worker, 'js');
 });
diff --git a/lib/workers/framer.js b/lib/workers/framer.js
index e58b8eb8..8737b71f 100644
--- a/lib/workers/framer.js
+++ b/lib/workers/framer.js
@@ -12,8 +12,6 @@ var BN = require('bn.js');
 var utils = require('../utils/utils');
 var assert = require('assert');
 var BufferWriter = require('../utils/writer');
-var MTX = require('../primitives/mtx');
-var TX = require('../primitives/tx');
 var KeyRing = require('../primitives/keyring');
 var Script = require('../script/script');
 var Witness = require('../script/witness');
@@ -88,10 +86,10 @@ Framer.item = function _item(item, writer) {
       } else if (item instanceof Witness) {
         p.writeU8(41);
         item.toRaw(p);
-      } else if (item instanceof MTX) {
+      } else if (isMTX(item)) {
         p.writeU8(42);
         item.toExtended(true, p);
-      } else if (item instanceof TX) {
+      } else if (isTX(item)) {
         p.writeU8(43);
         item.toExtended(true, p);
       } else if (item instanceof KeyRing) {
@@ -128,6 +126,18 @@ Framer.item = function _item(item, writer) {
   return p;
 };
 
+/*
+ * Helpers
+ */
+
+function isTX(tx) {
+  return tx && tx.witnessHash && tx.mutable === false;
+}
+
+function isMTX(tx) {
+  return tx && tx.witnessHash && tx.mutable === true;
+}
+
 /*
  * Expose
  */
diff --git a/lib/workers/jobs.js b/lib/workers/jobs.js
index 2dfe2f2b..448a23e9 100644
--- a/lib/workers/jobs.js
+++ b/lib/workers/jobs.js
@@ -19,11 +19,35 @@ var mine = require('../miner/mine');
 var jobs = exports;
 
 /**
- * Master process.
- * @type {Master}
+ * Execute a job on the worker.
+ * @param {String} cmd
+ * @param {Array} args
+ * @returns {Object}
+ * @throws on unknown command
  */
 
-jobs.master = null;
+jobs.execute = function execute(cmd, args) {
+  switch (cmd) {
+    case 'verify':
+      return jobs.verify(args[0], args[1]);
+    case 'verifyInput':
+      return jobs.verifyInput(args[0], args[1], args[2]);
+    case 'sign':
+      return jobs.sign(args[0], args[1], args[2]);
+    case 'signInput':
+      return jobs.signInput(args[0], args[1], args[2], args[3]);
+    case 'ecVerify':
+      return jobs.ecVerify(args[0], args[1], args[2]);
+    case 'ecSign':
+      return jobs.ecSign(args[0], args[1]);
+    case 'mine':
+      return jobs.mine(args[0], args[1], args[2], args[3]);
+    case 'scrypt':
+      return jobs.scrypt(args[0], args[1], args[2], args[3], args[4], args[5]);
+    default:
+      throw new Error('Unknown command: "' + cmd + '".');
+  }
+};
 
 /**
  * Execute tx.verify() on worker.
diff --git a/lib/workers/master.js b/lib/workers/master.js
new file mode 100644
index 00000000..1d8a6869
--- /dev/null
+++ b/lib/workers/master.js
@@ -0,0 +1,223 @@
+/*!
+ * workers.js - worker processes for bcoin
+ * Copyright (c) 2014-2015, Fedor Indutny (MIT License)
+ * Copyright (c) 2014-2016, Christopher Jeffrey (MIT License).
+ * https://github.com/bcoin-org/bcoin
+ */
+
+'use strict';
+
+var EventEmitter = require('events').EventEmitter;
+var utils = require('../utils/utils');
+var global = utils.global;
+var Network = require('../protocol/network');
+var jobs = require('./jobs');
+var Parser = require('./parser-client');
+var Framer = require('./framer');
+var global = utils.global;
+var server;
+
+/**
+ * Represents the master process.
+ * @exports Master
+ * @constructor
+ */
+
+function Master() {
+  if (!(this instanceof Master))
+    return new Master();
+
+  EventEmitter.call(this);
+
+  this.framer = new Framer();
+  this.parser = new Parser();
+
+  this._init();
+}
+
+utils.inherits(Master, EventEmitter);
+
+/**
+ * Initialize master. Bind events.
+ * @private
+ */
+
+Master.prototype._init = function _init() {
+  var self = this;
+
+  if (utils.isBrowser) {
+    global.onerror = function onerror(err) {
+      self.emit('error', err);
+    };
+    global.onmessage = function onmessage(event) {
+      var data;
+      if (typeof event.data !== 'string') {
+        data = event.data.buf;
+        data.__proto__ = Buffer.prototype;
+      } else {
+        data = new Buffer(event.data, 'hex');
+      }
+      self.emit('data', data);
+    };
+  } else {
+    process.stdin.on('data', function(data) {
+      self.emit('data', data);
+    });
+    // Nowhere to send these errors:
+    process.stdin.on('error', utils.nop);
+    process.stdout.on('error', utils.nop);
+    process.stderr.on('error', utils.nop);
+  }
+
+  this.on('data', function(data) {
+    self.parser.feed(data);
+  });
+
+  this.parser.on('error', function(e) {
+    self.emit('error', e);
+  });
+
+  this.parser.on('packet', function(packet) {
+    self.emit('packet', packet);
+  });
+};
+
+/**
+ * Set primary network.
+ * @param {NetworkType|Network} network
+ */
+
+Master.prototype.set = function set(network) {
+  return Network.set(network);
+};
+
+/**
+ * Send data to worker.
+ * @param {Buffer} data
+ * @returns {Boolean}
+ */
+
+Master.prototype.write = function write(data) {
+  if (utils.isBrowser) {
+    if (global.postMessage.length === 2) {
+      data.__proto__ = Uint8Array.prototype;
+      global.postMessage({ buf: data }, [data]);
+    } else {
+      global.postMessage(data.toString('hex'));
+    }
+    return true;
+  }
+  return process.stdout.write(data);
+};
+
+/**
+ * Frame and send a packet.
+ * @param {String} job
+ * @param {String} cmd
+ * @param {Array} items
+ * @returns {Boolean}
+ */
+
+Master.prototype.send = function send(job, cmd, items) {
+  return this.write(this.framer.packet(job, cmd, items));
+};
+
+/**
+ * Emit an event on the worker side.
+ * @param {String} event
+ * @param {...Object} arg
+ * @returns {Boolean}
+ */
+
+Master.prototype.sendEvent = function sendEvent() {
+  var items = new Array(arguments.length);
+  var i;
+
+  for (i = 0; i < items.length; i++)
+    items[i] = arguments[i];
+
+  return this.send(0, 'event', items);
+};
+
+/**
+ * Destroy the worker.
+ */
+
+Master.prototype.destroy = function destroy() {
+  if (utils.isBrowser)
+    return global.close();
+  return process.exit(0);
+};
+
+/**
+ * Write a message to stdout in the master process.
+ * @param {Object|String} obj
+ * @param {...String} args
+ */
+
+Master.prototype.log = function log() {
+  var items = new Array(arguments.length);
+  var i;
+
+  for (i = 0; i < items.length; i++)
+    items[i] = arguments[i];
+
+  this.sendEvent('log', items);
+};
+
+/**
+ * Listen for messages from master process (only if worker).
+ * @param {Object} env
+ * @returns {Master}
+ */
+
+Master.prototype.listen = function listen(env) {
+  var self = this;
+
+  Network.set(env.BCOIN_WORKER_NETWORK);
+
+  utils.log = this.log.bind(this);
+  utils.error = utils.log;
+
+  this.on('error', function(err) {
+    self.sendEvent('worker error', fromError(err));
+  });
+
+  this.on('packet', function(packet) {
+    var result;
+
+    if (packet.cmd === 'event') {
+      self.emit('event', packet.items);
+      self.emit.apply(self, packet.items);
+      return;
+    }
+
+    try {
+      result = jobs.execute(packet.cmd, packet.items);
+    } catch (e) {
+      self.send(packet.job, 'response', [fromError(e)]);
+      return;
+    }
+
+    self.send(packet.job, 'response', [null, result]);
+  });
+};
+
+/*
+ * Helpers
+ */
+
+function fromError(err) {
+  return [err.message, err.stack + '', err.type];
+}
+
+/*
+ * Expose
+ */
+
+server = new Master();
+
+if (utils.isBrowser)
+  global.master = server;
+
+module.exports = server;
diff --git a/lib/workers/parser-client.js b/lib/workers/parser-client.js
new file mode 100644
index 00000000..aba8fc9d
--- /dev/null
+++ b/lib/workers/parser-client.js
@@ -0,0 +1,46 @@
+/*!
+ * workers.js - worker processes for bcoin
+ * Copyright (c) 2014-2015, Fedor Indutny (MIT License)
+ * Copyright (c) 2014-2016, Christopher Jeffrey (MIT License).
+ * https://github.com/bcoin-org/bcoin
+ */
+
+'use strict';
+
+var utils = require('../utils/utils');
+var ServerParser = require('./parser');
+var MTX = require('../primitives/mtx');
+var TX = require('../primitives/tx');
+var KeyRing = require('../primitives/keyring');
+
+/**
+ * Parser
+ * @constructor
+ */
+
+function Parser() {
+  if (!(this instanceof Parser))
+    return new Parser();
+
+  ServerParser.call(this);
+}
+
+utils.inherits(Parser, ServerParser);
+
+Parser.prototype.parseKeyRing = function parseKeyRing(data) {
+  return KeyRing.fromRaw(data);
+};
+
+Parser.prototype.parseMTX = function parseMTX(data) {
+  return MTX.fromExtended(data, true);
+};
+
+Parser.prototype.parseTX = function parseTX(data) {
+  return TX.fromExtended(data, true);
+};
+
+/*
+ * Expose
+ */
+
+module.exports = Parser;
diff --git a/lib/workers/parser.js b/lib/workers/parser.js
index d67f17fd..2371c7f6 100644
--- a/lib/workers/parser.js
+++ b/lib/workers/parser.js
@@ -12,9 +12,6 @@ var BN = require('bn.js');
 var utils = require('../utils/utils');
 var assert = require('assert');
 var BufferReader = require('../utils/reader');
-var MTX = require('../primitives/mtx');
-var TX = require('../primitives/tx');
-var KeyRing = require('../primitives/keyring');
 var Script = require('../script/script');
 var Witness = require('../script/witness');
 
@@ -147,10 +144,6 @@ Parser.prototype.parseHeader = function parseHeader(data) {
 };
 
 Parser.prototype.parseBody = function parseBody(data) {
-  return Parser.parseItem(data);
-};
-
-Parser.parseItem = function parseItem(data) {
   var p = BufferReader(data);
   var i, count, items;
 
@@ -171,13 +164,13 @@ Parser.parseItem = function parseItem(data) {
       items = [];
       count = p.readVarint();
       for (i = 0; i < count; i++)
-        items.push(Parser.parseItem(p));
+        items.push(this.parseBody(p));
       return items;
     case 7:
       items = {};
       count = p.readVarint();
       for (i = 0; i < count; i++)
-        items[p.readVarString('utf8')] = Parser.parseItem(p);
+        items[p.readVarString('utf8')] = this.parseBody(p);
       return items;
     case 10:
       return new BN(p.readVarBytes());
@@ -186,16 +179,28 @@ Parser.parseItem = function parseItem(data) {
     case 41:
       return Witness.fromRaw(p);
     case 42:
-      return MTX.fromExtended(p, true);
+      return this.parseMTX(p);
     case 43:
-      return TX.fromExtended(p, true);
+      return this.parseTX(p);
     case 44:
-      return KeyRing.fromRaw(p);
+      return this.parseKeyRing(p);
     default:
       throw new Error('Bad type.');
   }
 };
 
+Parser.prototype.parseKeyRing = function parseKeyRing(data) {
+  throw new Error('KeyRing in client output.');
+};
+
+Parser.prototype.parseMTX = function parseMTX(data) {
+  throw new Error('MTX in client output.');
+};
+
+Parser.prototype.parseTX = function parseTX(data) {
+  throw new Error('TX in client output.');
+};
+
 /**
  * Packet
  * @constructor
diff --git a/lib/workers/worker-browser.js b/lib/workers/worker-browser.js
index 9d930b4a..212d4631 100644
--- a/lib/workers/worker-browser.js
+++ b/lib/workers/worker-browser.js
@@ -9,17 +9,14 @@
 
 /* jshint worker: true */
 
-var bcoin, env;
-
-self.importScripts('/bcoin.js');
-
-bcoin = self.bcoin;
+self.importScripts('/bcoin-master.js');
 
 self.onmessage = function onmessage(event) {
+  var env;
+
   self.onmessage = function() {};
 
   env = JSON.parse(event.data);
 
-  bcoin.set(env.BCOIN_WORKER_NETWORK);
-  bcoin.workers.listen();
+  self.master.listen(env);
 };
diff --git a/lib/workers/worker.js b/lib/workers/worker.js
index 68624d63..1e71b37f 100644
--- a/lib/workers/worker.js
+++ b/lib/workers/worker.js
@@ -7,8 +7,6 @@
 
 'use strict';
 
-var env = process.env;
-var bcoin = require('../env');
+var master = require('./master');
 
-bcoin.set(env.BCOIN_WORKER_NETWORK);
-bcoin.workers.listen();
+master.listen(process.env);
diff --git a/lib/workers/workers.js b/lib/workers/workers.js
index f08b2e73..8e798cf2 100644
--- a/lib/workers/workers.js
+++ b/lib/workers/workers.js
@@ -225,7 +225,7 @@ WorkerPool.prototype.execute = function execute(method, args, timeout) {
     return new Promise(function(resolve, reject) {
       utils.nextTick(function() {
         try {
-          result = jobs[method].apply(jobs, args);
+          result = jobs.execute(method, args);
         } catch (e) {
           reject(e);
           return;
@@ -652,184 +652,6 @@ Worker.prototype.execute = function execute(method, args, timeout) {
   });
 };
 
-/**
- * Represents the master process.
- * @exports Master
- * @constructor
- */
-
-function Master() {
-  if (!(this instanceof Master))
-    return new Master();
-
-  EventEmitter.call(this);
-
-  this.framer = new Framer();
-  this.parser = new Parser();
-
-  this._init();
-}
-
-utils.inherits(Master, EventEmitter);
-
-/**
- * Initialize master. Bind events.
- * @private
- */
-
-Master.prototype._init = function _init() {
-  var self = this;
-
-  if (utils.isBrowser) {
-    global.onerror = function onerror(err) {
-      self.emit('error', err);
-    };
-    global.onmessage = function onmessage(event) {
-      var data;
-      if (typeof event.data !== 'string') {
-        data = event.data.buf;
-        data.__proto__ = Buffer.prototype;
-      } else {
-        data = new Buffer(event.data, 'hex');
-      }
-      self.emit('data', data);
-    };
-  } else {
-    process.stdin.on('data', function(data) {
-      self.emit('data', data);
-    });
-    // Nowhere to send these errors:
-    process.stdin.on('error', utils.nop);
-    process.stdout.on('error', utils.nop);
-    process.stderr.on('error', utils.nop);
-  }
-
-  this.on('data', function(data) {
-    self.parser.feed(data);
-  });
-
-  this.parser.on('error', function(e) {
-    self.emit('error', e);
-  });
-
-  this.parser.on('packet', function(packet) {
-    self.emit('packet', packet);
-  });
-};
-
-/**
- * Send data to worker.
- * @param {Buffer} data
- * @returns {Boolean}
- */
-
-Master.prototype.write = function write(data) {
-  if (utils.isBrowser) {
-    if (global.postMessage.length === 2) {
-      data.__proto__ = Uint8Array.prototype;
-      global.postMessage({ buf: data }, [data]);
-    } else {
-      global.postMessage(data.toString('hex'));
-    }
-    return true;
-  }
-  return process.stdout.write(data);
-};
-
-/**
- * Frame and send a packet.
- * @param {String} job
- * @param {String} cmd
- * @param {Array} items
- * @returns {Boolean}
- */
-
-Master.prototype.send = function send(job, cmd, items) {
-  return this.write(this.framer.packet(job, cmd, items));
-};
-
-/**
- * Emit an event on the worker side.
- * @param {String} event
- * @param {...Object} arg
- * @returns {Boolean}
- */
-
-Master.prototype.sendEvent = function sendEvent() {
-  var items = new Array(arguments.length);
-  var i;
-
-  for (i = 0; i < items.length; i++)
-    items[i] = arguments[i];
-
-  return this.send(0, 'event', items);
-};
-
-/**
- * Destroy the worker.
- */
-
-Master.prototype.destroy = function destroy() {
-  if (utils.isBrowser)
-    return global.close();
-  return process.exit(0);
-};
-
-/**
- * Write a message to stdout in the master process.
- * @param {Object|String} obj
- * @param {...String} args
- */
-
-Master.prototype.log = function log() {
-  var items = new Array(arguments.length);
-  var i;
-
-  for (i = 0; i < items.length; i++)
-    items[i] = arguments[i];
-
-  this.sendEvent('log', items);
-};
-
-/**
- * Listen for messages from master process (only if worker).
- * @returns {Master}
- */
-
-Master.listen = function listen() {
-  var master = new Master();
-
-  utils.log = master.log.bind(master);
-  utils.error = utils.log;
-
-  master.on('error', function(err) {
-    master.sendEvent('worker error', fromError(err));
-  });
-
-  master.on('packet', function(packet) {
-    var result;
-
-    if (packet.cmd === 'event') {
-      master.emit('event', packet.items);
-      master.emit.apply(master, packet.items);
-      return;
-    }
-
-    try {
-      result = jobs[packet.cmd].apply(jobs, packet.items);
-    } catch (e) {
-      master.send(packet.job, 'response', [fromError(e)]);
-      return;
-    }
-
-    master.send(packet.job, 'response', [null, result]);
-  });
-
-  jobs.master = master;
-
-  return master;
-};
-
 /*
  * Helpers
  */
@@ -837,6 +659,7 @@ Master.listen = function listen() {
 function getCores() {
   if (os.unsupported)
     return 2;
+
   return os.cpus().length;
 }
 
@@ -847,10 +670,6 @@ function toError(values) {
   return err;
 }
 
-function fromError(err) {
-  return [err.message, err.stack + '', err.type];
-}
-
 /*
  * Default
  */
@@ -888,7 +707,5 @@ exports.set({
 
 exports.WorkerPool = WorkerPool;
 exports.Worker = Worker;
-exports.Master = Master;
 exports.Framer = Framer;
 exports.Parser = Parser;
-exports.listen = Master.listen;
diff --git a/package.json b/package.json
index 0ee0f70a..b2d6642f 100644
--- a/package.json
+++ b/package.json
@@ -12,9 +12,9 @@
   "preferGlobal": true,
   "scripts": {
     "test": "mocha --reporter spec test/*-test.js",
-    "browserify": "browserify --im -o browser/bcoin.js lib/bcoin.js",
-    "uglify": "uglifyjs -m -o browser/bcoin.min.js browser/bcoin.js",
-    "clean": "rm browser/bcoin.js browser/bcoin.min.js",
+    "browserify": "browserify --im -o browser/bcoin.js lib/bcoin.js && browserify --im -o browser/bcoin-master.js lib/workers/master.js",
+    "uglify": "uglifyjs -m -o browser/bcoin.min.js browser/bcoin.js && uglifyjs -m -o browser/bcoin-master.min.js browser/bcoin-master.js",
+    "clean": "rm browser/bcoin.js browser/bcoin.min.js browser/bcoin-master.js browser/bcoin-master.min.js",
     "lint": "jshint lib/ || exit 0"
   },
   "repository": "git://github.com/bcoin-org/bcoin.git",