diff --git a/lib/txin.js b/lib/txin.js
new file mode 100644
index 000000000..15a715f9e
--- /dev/null
+++ b/lib/txin.js
@@ -0,0 +1,58 @@
+var BufferReader = require('./bufferreader');
+var BufferWriter = require('./bufferwriter');
+var Varint = require('./varint');
+var Script = require('./script');
+
+var Txin = function Txin(txidbuf, txoutnum, varint, script, seqnum) {
+  if (!(this instanceof Txin))
+    return new Txin(txidbuf, txoutnum, varint, script, seqnum);
+  if (Buffer.isBuffer(txidbuf)) {
+    this.txidbuf = txidbuf;
+    this.txoutnum = txoutnum;
+    this.varint = varint;
+    this.script = script;
+    this.seqnum = seqnum;
+  } else if (txidbuf) {
+    var obj = txidbuf;
+    this.set(obj);
+  }
+};
+
+Txin.prototype.set = function(obj) {
+  this.txidbuf = obj.txidbuf || this.txidbuf;
+  this.txoutnum = typeof obj.txoutnum !== 'undefined' ? obj.txoutnum : this.txoutnum;
+  this.varint = typeof obj.varint !== 'undefined' ? obj.varint : this.varint;
+  this.script = obj.script || this.script;
+  this.seqnum = typeof obj.seqnum !== 'undefined' ? obj.seqnum : this.seqnum;
+  return this;
+};
+
+Txin.prototype.fromBuffer = function(buf) {
+  return this.fromBufferReader(BufferReader(buf));
+};
+
+Txin.prototype.fromBufferReader = function(br) {
+  this.txidbuf = br.buffer(32);
+  this.txoutnum = br.readUInt32LE();
+  this.varint = Varint(br.readVarintBuf());
+  this.script = Script().fromBuffer(br.buffer(this.varint.toNumber()));
+  this.seqnum = br.readUInt32LE();
+  return this;
+};
+
+Txin.prototype.toBuffer = function() {
+  return this.toBufferWriter().concat();
+};
+
+Txin.prototype.toBufferWriter = function(bw) {
+  if (!bw)
+    bw = new BufferWriter();
+  bw.write(this.txidbuf);
+  bw.writeUInt32LE(this.txoutnum);
+  bw.write(this.varint.buf);
+  bw.write(this.script.toBuffer());
+  bw.writeUInt32LE(this.seqnum);
+  return bw;
+};
+
+module.exports = Txin;
diff --git a/test/txin.js b/test/txin.js
new file mode 100644
index 000000000..ec3e1e8e1
--- /dev/null
+++ b/test/txin.js
@@ -0,0 +1,90 @@
+var should = require('chai').should();
+var Script = require('../lib/script');
+var Txin = require('../lib/txin');
+var Varint = require('../lib/varint');
+var BufferReader = require('../lib/bufferreader');
+
+describe('Txin', function() {
+  
+  it('should make a new txin', function() {
+    var txin = new Txin();
+    should.exist(txin);
+    txin = Txin();
+    should.exist(txin);
+  });
+
+  var txidbuf = new Buffer(32);
+  txidbuf.fill(0);
+  var txoutnum = 0;
+  var script = Script().fromString("OP_CHECKMULTISIG");
+  var varint = Varint(script.toBuffer().length);
+  var seqnum = 0;
+  var txin = Txin().set({
+    txidbuf: txidbuf,
+    txoutnum: txoutnum,
+    varint: varint,
+    script: script,
+    seqnum: seqnum
+  });
+
+  describe('#set', function() {
+    
+    it('should set these vars', function() {
+      var txin = Txin().set({
+        txidbuf: txidbuf,
+        txoutnum: txoutnum,
+        varint: varint,
+        script: script,
+        seqnum: seqnum
+      });
+      should.exist(txin.txidbuf);
+      should.exist(txin.txoutnum);
+      should.exist(txin.varint);
+      should.exist(txin.script);
+      should.exist(txin.seqnum);
+    });
+
+  });
+
+  describe('#fromBuffer', function() {
+    
+    it('should convert this known buffer', function() {
+      var hex = '00000000000000000000000000000000000000000000000000000000000000000000000001ae00000000';
+      var buf = new Buffer(hex, 'hex');
+      var txin = Txin().fromBuffer(buf);
+      txin.varint.toNumber().should.equal(1);
+      txin.script.toString().should.equal('OP_CHECKMULTISIG');
+    });
+
+  });
+
+  describe('#fromBufferReader', function() {
+    
+    it('should convert this known buffer', function() {
+      var hex = '00000000000000000000000000000000000000000000000000000000000000000000000001ae00000000';
+      var buf = new Buffer(hex, 'hex');
+      var br = BufferReader(buf);
+      var txin = Txin().fromBufferReader(br);
+      txin.varint.toNumber().should.equal(1);
+      txin.script.toString().should.equal('OP_CHECKMULTISIG');
+    });
+
+  });
+
+  describe('#toBuffer', function() {
+    
+    it('should convert this known buffer', function() {
+      txin.toBuffer().toString('hex').should.equal('00000000000000000000000000000000000000000000000000000000000000000000000001ae00000000');
+    });
+
+  });
+
+  describe('#toBufferWriter', function() {
+    
+    it('should convert this known buffer', function() {
+      txin.toBufferWriter().concat().toString('hex').should.equal('00000000000000000000000000000000000000000000000000000000000000000000000001ae00000000');
+    });
+
+  });
+
+});