diff --git a/examples/mam_js_send.py b/examples/mam_js_send.py
new file mode 100644
index 0000000..c52f998
--- /dev/null
+++ b/examples/mam_js_send.py
@@ -0,0 +1,229 @@
+# coding=utf-8
+from __future__ import absolute_import, division, print_function, \
+  unicode_literals
+
+import codecs
+import json
+from argparse import ArgumentParser
+from pprint import pformat
+from subprocess import PIPE, run
+from typing import List, Optional, Text
+
+import filters as f
+from six import binary_type, text_type
+
+from iota import Bundle, Iota, TransactionTrytes
+from iota.bin import IotaCommandLineApp
+from iota.json import JsonEncoder
+from iota.crypto.addresses import AddressGenerator
+from iota.filters import Trytes
+
+
+class IotaMamExample(IotaCommandLineApp):
+  """
+  Shows how to integrate the ``mam.client.js`` Javascript library into a
+  Python script, until MAM functionality is implemented in PyOTA.
+
+  In order to execute this script, you must install Node and the
+  ``mam.client.js`` library.
+
+  See https://github.com/iotaledger/mam.client.js for more information.
+  """
+  def execute(self, api, **arguments):
+    # type: (Iota, ...) -> int
+    channel_key_index     = arguments['channel_key_index'] # type: int
+    count                 = arguments['count'] # type: int
+    depth                 = arguments['depth'] # type: int
+    dry_run               = arguments['dry_run'] # type: bool
+    mam_encrypt_path      = arguments['mam_encrypt_path'] # type: Text
+    min_weight_magnitude  = arguments['min_weight_magnitude'] # type: int
+    message_encoding      = arguments['message_encoding'] # type: Text
+    message_file          = arguments['message_file'] # type: Optional[Text]
+    security_level        = arguments['security_level'] # type: int
+    start                 = arguments['start'] # type: int
+
+    if message_file:
+      with codecs.open(message_file, 'r', message_encoding) as f_: # type: codecs.StreamReaderWriter
+        message = f_.read()
+
+    else:
+      self.stdout.write(
+        'Enter message to send.  Press Ctrl-D on a blank line when done.\n\n',
+      )
+
+      message = self.stdin.read().strip()
+      self.stdout.write('\n')
+
+    # Generating the encrypted message may take a little while, so we
+    # should provide some feedback to the user so that they know that
+    # their input is being processed (this is especially important if
+    # the user typed in their message, so that they don't press ^D
+    # again, thinking that the program didn't register the first one).
+    self.stdout.write('Encrypting message...\n')
+
+    proc =\
+      run(
+        args = [
+          # mam_encrypt.js
+          mam_encrypt_path,
+
+          # Required arguments
+          binary_type(api.seed),
+          message,
+
+          # Options
+          '--channel-key-index', text_type(channel_key_index),
+          '--start', text_type(start),
+          '--count', text_type(count),
+          '--security-level', text_type(security_level),
+        ],
+
+        check   = True,
+        stdout  = PIPE,
+        stderr  = self.stderr,
+      )
+
+    # The output of the JS script is a collection of transaction
+    # trytes, encoded as JSON.
+    filter_ =\
+      f.FilterRunner(
+        starting_filter =
+            f.Required
+          | f.Unicode
+          | f.JsonDecode
+          | f.Array
+          | f.FilterRepeater(
+                f.ByteString(encoding='ascii')
+              | Trytes(result_type=TransactionTrytes)
+            ),
+
+        incoming_data = proc.stdout,
+      )
+
+    if not filter_.is_valid():
+      self.stderr.write(
+        'Invalid output from {mam_encrypt_path}:\n'
+        '\n'
+        'Output:\n'
+        '{output}\n'
+        '\n'
+        'Errors:\n'
+        '{errors}\n'.format(
+          errors            = pformat(filter_.get_errors(with_context=True)),
+          mam_encrypt_path  = mam_encrypt_path,
+          output            = proc.stdout,
+        ),
+      )
+
+      return 2
+
+    transaction_trytes = filter_.cleaned_data # type: List[TransactionTrytes]
+
+    if dry_run:
+      bundle = Bundle.from_tryte_strings(transaction_trytes)
+
+      self.stdout.write('Transactions:\n\n')
+      self.stdout.write(json.dumps(bundle, cls=JsonEncoder, indent=2))
+    else:
+      api.send_trytes(
+        depth                 = depth,
+        trytes                = transaction_trytes,
+        min_weight_magnitude  = min_weight_magnitude,
+      )
+
+    return 0
+
+  def create_argument_parser(self):
+    # type: () -> ArgumentParser
+    parser = super(IotaMamExample, self).create_argument_parser()
+
+    parser.add_argument(
+      'mam_encrypt_path',
+
+        help = 'Path to `mam_encrypt.js` script.',
+    )
+
+    parser.add_argument(
+      '--channel-key-index',
+        default = 0,
+        dest    = 'channel_key_index',
+        type    = int,
+
+        help = 'Index of the key used to establish the channel.',
+    )
+
+    parser.add_argument(
+      '--start',
+        default = 0,
+        type    = int,
+
+        help = 'Index of the first key used to encrypt the message.',
+    )
+
+    parser.add_argument(
+      '--count',
+        default = 1,
+        type    = int,
+
+        help = 'Number of keys to use to encrypt the message.',
+    )
+
+    parser.add_argument(
+      '--security-level',
+        default = AddressGenerator.DEFAULT_SECURITY_LEVEL,
+        type    = int,
+
+        help = 'Number of iterations to use when generating keys.',
+    )
+
+    parser.add_argument(
+      '--message-file',
+        dest = 'message_file',
+
+        help =
+          'Path to file containing the message to send. '
+          'If not provided, you will be prompted for the message via stdin.',
+    )
+
+    parser.add_argument(
+      '--message-encoding',
+        dest    = 'message_encoding',
+        default = 'utf-8',
+
+        help = 'Encoding used to interpret message.',
+    )
+
+    parser.add_argument(
+      '--depth',
+        default = 3,
+        type    = int,
+
+        help = 'Depth at which to attach the resulting transactions.',
+    )
+
+    parser.add_argument(
+      '--min-weight-magnitude',
+        dest  = 'min_weight_magnitude',
+        type  = int,
+
+        help =
+          'Min weight magnitude, used by the node to calibrate PoW. '
+          'If not provided, a default value will be used.',
+    )
+
+    parser.add_argument(
+      '--dry-run',
+        action  = 'store_true',
+        default = False,
+        dest    = 'dry_run',
+
+        help =
+          'If set, resulting transactions will be sent to stdout instead of'
+          'broadcasting to the Tangle.',
+    )
+
+    return parser
+
+
+if __name__ == '__main__':
+  IotaMamExample().main()
diff --git a/src/iota/bin/__init__.py b/src/iota/bin/__init__.py
index 20597c0..c41cdf1 100644
--- a/src/iota/bin/__init__.py
+++ b/src/iota/bin/__init__.py
@@ -29,12 +29,13 @@ class IotaCommandLineApp(with_metaclass(ABCMeta)):
   Whether the command requires the user to provide a seed.
   """
 
-  def __init__(self, stdout=sys.stdout, stderr=sys.stderr):
-    # type: (StringIO, StringIO) -> None
+  def __init__(self, stdout=sys.stdout, stderr=sys.stderr, stdin=sys.stdin):
+    # type: (StringIO, StringIO, StringIO) -> None
     super(IotaCommandLineApp, self).__init__()
 
     self.stdout = stdout
     self.stderr = stderr
+    self.stdin  = stdin
 
   @abstract_method
   def execute(self, api, **arguments):
@@ -113,7 +114,7 @@ def create_argument_parser(self):
     arguments and options from argv.
     """
     parser = ArgumentParser(
-      description = __doc__,
+      description = self.__doc__,
       epilog      = 'PyOTA v{version}'.format(version=__version__),
     )
 
@@ -139,6 +140,13 @@ def create_argument_parser(self):
             'via stdin.',
       )
 
+    parser.add_argument(
+      '--testnet',
+        action  = 'store_true',
+        default = False,
+        help    = 'If set, use testnet settings (e.g., for PoW).',
+    )
+
     return parser
 
   @staticmethod
diff --git a/src/iota/bin/repl.py b/src/iota/bin/repl.py
index 85d388b..253cdc9 100755
--- a/src/iota/bin/repl.py
+++ b/src/iota/bin/repl.py
@@ -72,13 +72,6 @@ def create_argument_parser(self):
         help    = 'URI of node to send POW requests to.'
     )
 
-    parser.add_argument(
-      '--testnet',
-        action  = 'store_true',
-        default = False,
-        help    = 'If set, use testnet settings (e.g., for PoW).',
-    )
-
     parser.add_argument(
       '--debug',
         action  = 'store_true',