diff --git a/assemble_msg.py b/assemble_msg.py
new file mode 100644
index 0000000..aad7c9f
--- /dev/null
+++ b/assemble_msg.py
@@ -0,0 +1,221 @@
+import hashlib
+import logging
+import random
+import time
+from binascii import hexlify, unhexlify
+from struct import pack
+
+from pybitmessage import (
+    defaults, helper_msgcoding, highlevelcrypto, protocol, shared)
+from pybitmessage.addresses import (
+    decodeAddress, decodeVarint, encodeAddress, encodeVarint)
+from pybitmessage.fallback import RIPEMD160Hash
+from pybitmessage.helper_ackPayload import genAckPayload
+
+
+logger = logging.getLogger('default')
+
+
+class Address(object):
+    version = 4
+    stream = 1
+    sigkey = None
+    enkey = None
+    ripe = None
+    bitfield = pack('>I', 0)
+    avg_pow = defaults.networkDefaultProofOfWorkNonceTrialsPerByte
+    avg_extra_bytes = defaults.networkDefaultPayloadLengthExtraBytes
+
+    @classmethod
+    def fromData(cls, data, addr=None):
+        # parse addr_data
+        # SELECT transmitdata FROM pubkeys WHERE address = ?
+        version, _ = decodeVarint(data[0])
+        pos = 1
+        stream, length = decodeVarint(data[pos:pos + 10])
+        pos += length
+        bitfield = data[pos:pos + 4]
+        # TODO: mobile
+        pos += 4
+        sigkey = data[pos:pos + 64]
+        pos += 64
+        enkey = data[pos:pos + 64]
+        pos += 64
+
+        if version >= 3:
+            avg_pow = decodeVarint(data[pos:pos + 10])
+            pos += length
+            extra_bytes, length = decodeVarint(data[pos:pos + 10])
+            avg_pow = max(
+                defaults.networkDefaultProofOfWorkNonceTrialsPerByte, avg_pow)
+            extra_bytes = max(
+                defaults.networkDefaultPayloadLengthExtraBytes, extra_bytes)
+        else:
+            avg_pow = None
+            extra_bytes = None
+        return cls(
+            version, stream, sigkey, enkey,
+            addr=addr, avg_pow=avg_pow, extra_bytes=extra_bytes,
+            bitfield=bitfield)
+
+    def __init__(
+        self, version, stream, sigkey, enkey, addr=None, ripe=None,
+        avg_pow=None, extra_bytes=None, bitfield=None
+    ):
+        self.version = version
+        self.stream = stream
+        self.sigkey = sigkey
+        self.enkey = enkey
+        if bitfield:
+            self.bitfield = bitfield
+        if ripe is None:
+            if addr:
+                status, dversion, dstream, ripe = decodeAddress(addr)
+                assert status == 'success'
+                assert version == dversion
+                assert stream == dstream
+            else:
+                _sha = hashlib.new('sha512')
+                _sha.update(sigkey + enkey)
+                ripe = RIPEMD160Hash(_sha.digest()).digest()
+        self.ripe = ripe
+        if avg_pow:
+            self.avg_pow = avg_pow
+        if extra_bytes:
+            self.extra_bytes = extra_bytes
+        self.addr = addr or encodeAddress(self.version, self.stream, self.ripe)
+
+    def encrypt(self, data):
+        return highlevelcrypto.encrypt(data, b'04' + hexlify(self.enkey))
+
+
+class Identity(Address):
+    priv_sigkey = None
+    priv_enkey = None
+
+    @classmethod
+    def fromWIF(cls, sigkey, enkey, bitfield=pack('>I', 0)):
+        return cls(
+            hexlify(shared.decodeWalletImportFormat(sigkey)),
+            hexlify(shared.decodeWalletImportFormat(enkey)), bitfield=bitfield)
+
+    @classmethod
+    def fromConfig(cls, addr, config):
+        sigkey_base58 = config.get(addr, 'privsigningkey')
+        enkey_base58 = config.get(addr, 'privencryptionkey')
+        bitfield = 0
+        # send ack
+        if not config.safeGetBoolean(addr, 'dontsendack'):
+            bitfield |= protocol.BITFIELD_DOESACK
+        return cls.fromWIF(
+            sigkey_base58, enkey_base58, bitfield=pack('>I', bitfield))
+
+    def __init__(
+        self, sigkey, enkey, addr=None, bitfield=None,
+        version=None, stream=None, ripe=None,
+        avg_pow=None, extra_bytes=None
+    ):
+        self.priv_sigkey = sigkey
+        self.priv_enkey = enkey
+        if version:
+            self.version = version
+        if stream:
+            self.stream = stream
+        sigkey = unhexlify(highlevelcrypto.privToPub(sigkey))[1:]
+        enkey = unhexlify(highlevelcrypto.privToPub(enkey))[1:]
+        super(Identity, self).__init__(
+            self.version, self.stream, sigkey, enkey,
+            addr, ripe, avg_pow, extra_bytes)
+
+    def sign(self, data):
+        return highlevelcrypto.sign(data, self.priv_sigkey)
+
+    def decrypt(self):
+        pass
+
+
+def assemble_msg(
+    fromid, toaddr, subject, message,
+    friend=False, ttl=86400, encoding=2
+):
+
+    if ttl > 28 * 24 * 60 * 60:
+        ttl = 28 * 24 * 60 * 60
+    # add some randomness to the TTL
+    ttl = int(ttl + random.randrange(-300, 300))
+    embedded_time = int(time.time() + ttl)
+
+    payload = encodeVarint(fromid.version)
+    payload += encodeVarint(fromid.stream)
+    payload += fromid.bitfield
+
+    payload += fromid.sigkey + fromid.enkey
+
+    if fromid.version >= 3:
+        payload += encodeVarint(
+            defaults.networkDefaultProofOfWorkNonceTrialsPerByte if friend
+            else fromid.avg_pow)
+        payload += encodeVarint(
+            defaults.networkDefaultPayloadLengthExtraBytes if friend
+            else fromid.extra_bytes)
+
+    payload += toaddr.ripe
+    payload += encodeVarint(encoding)
+    encoded_message = helper_msgcoding.MsgEncode(
+        {"subject": subject, "body": message}, encoding)
+    payload += encodeVarint(encoded_message.length)
+    payload += encoded_message.data
+    if not protocol.checkBitfield(
+        toaddr.bitfield, protocol.BITFIELD_DOESACK
+    ):
+        logger.info(
+            'Not bothering to include ackdata because'
+            ' the receiver said that they won\'t relay it anyway.'
+        )
+        ack_payload = ''
+    else:
+        if ttl < 24 * 60 * 60:
+            ttl = 24 * 60 * 60  # 1 day
+        elif ttl < 7 * 24 * 60 * 60:
+            ttl = 7 * 24 * 60 * 60  # 1 week
+        else:
+            ttl = 28 * 24 * 60 * 60  # 4 weeks
+        ttl = int(ttl + random.randrange(-300, 300))
+        ack_payload = pack('>Q', int(time.time() + ttl)) + \
+            genAckPayload(toaddr.stream)
+
+    ack_payload = protocol.CreatePacket('object', ack_payload)
+
+    payload += encodeVarint(len(ack_payload))
+    payload += ack_payload
+
+    logger.info('Payload: %s', hexlify(payload))
+
+    header_tmp = pack('>Q', embedded_time) + '\x00\x00\x00\x02' + \
+        encodeVarint(1) + encodeVarint(toaddr.stream)
+
+    signature = fromid.sign(header_tmp + payload)
+    payload += encodeVarint(len(signature))
+    payload += signature
+
+    encrypted = toaddr.encrypt(payload)
+
+    encrypted_payload = header_tmp + encrypted
+
+    return encrypted_payload
+
+
+if __name__ == "__main__":
+    fromid = Identity(
+        '93d0b61371a54b53df143b954035d612f8efa8a3ed1cf842c2186bfd8f876665',
+        '4b0b73a54e19b059dc274ab69df095fe699f43b17397bca26fdf40f4d7400a3a',
+        'BM-onkVu1KKL2UaUss5Upg9vXmqd3esTmV79', version=2)
+    # TODO: generate -> [chan] test
+    toaddr = Identity.fromWIF(
+        '5JY1CFeeyN4eyfL35guWAuUqu5VLmd7LojtkNP6wmt5msZxxZ57',
+        '5J1oDgZDicNhUgbfzBDQqi2m5jUPnDrfZinnTqEEEaLv63jVFTM')
+    print(hexlify(
+        assemble_msg(
+            fromid, toaddr,
+            'hello', 'The quick brown fox jumps over the lazy dog.', True)
+    ))