diff --git a/.travis.yml b/.travis.yml
index 67ec308..3bcd6ab 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,5 @@
 language: python
+cache: pip
 python:
     - "2.7"
 
@@ -6,6 +7,8 @@ install:
     - pip install -r requirements-dev.txt
     - pip install .
 
-script: py.test -v tests/
+script:
+    - flake8
+    - py.test -v tests/
 
 after_success: curl -X POST https://readthedocs.org/build/pynsot
diff --git a/pynsot/commands/cmd_circuits.py b/pynsot/commands/cmd_circuits.py
index f0a4578..96d511e 100644
--- a/pynsot/commands/cmd_circuits.py
+++ b/pynsot/commands/cmd_circuits.py
@@ -9,7 +9,7 @@
 
 from pynsot.util import slugify
 from pynsot.vendor import click
-from . import callbacks
+from . import callbacks, types
 from .cmd_networks import DISPLAY_FIELDS as NETWORK_DISPLAY_FIELDS
 from .cmd_interfaces import DISPLAY_FIELDS as INTERFACE_DISPLAY_FIELDS
 from .cmd_devices import DISPLAY_FIELDS as DEVICE_DISPLAY_FIELDS
@@ -22,7 +22,7 @@
 # field names oto their human-readable form when calling .print_list().
 DISPLAY_FIELDS = (
     ('id', 'ID'),
-    ('name', 'Name'),
+    ('name', 'Name (Key)'),
     ('endpoint_a', 'Endpoint A'),
     ('endpoint_z', 'Endpoint Z'),
     ('attributes', 'Attributes'),
@@ -61,8 +61,8 @@ def cli(ctx):
     '--endpoint-a',
     metavar='INTERFACE_ID',
     required=True,
-    type=int,
-    help='Unique ID of the interface of the A side of the Circuit',
+    type=types.NATURAL_KEY,
+    help='Unique ID or key of the interface of the A side of the Circuit',
 )
 @click.option(
     '-n',
@@ -83,8 +83,8 @@ def cli(ctx):
     '-Z',
     '--endpoint-z',
     metavar='INTERFACE_ID',
-    type=int,
-    help='Unique ID of the interface on the Z side of the Circuit',
+    type=types.NATURAL_KEY,
+    help='Unique ID or key of the interface on the Z side of the Circuit',
 )
 @click.pass_context
 def add(ctx, attributes, endpoint_a, name, site_id, endpoint_z):
@@ -96,6 +96,9 @@ def add(ctx, attributes, endpoint_a, name, site_id, endpoint_z):
     where it is not an Interface that is tracked by NSoT (like a provider's
     interface).
 
+    For the -A/--endpoint-a and -Z/--endpoint-z options, you may provide either
+    the Interface ID or its natural key.
+
     The name (-n/--name) is optional. If it is not specified, it will be
     generated for you in the form of:
     {device_a}:{interface_a}_{device_z}:{interface_z}
@@ -128,6 +131,7 @@ def add(ctx, attributes, endpoint_a, name, site_id, endpoint_z):
     '-A',
     '--endpoint-a',
     metavar='INTERFACE_ID',
+    type=types.NATURAL_KEY,
     help='Filter to Circuits with endpoint_a interfaces that match this ID'
 )
 @click.option(
@@ -142,7 +146,8 @@ def add(ctx, attributes, endpoint_a, name, site_id, endpoint_z):
     '-i',
     '--id',
     metavar='ID',
-    help='Unique ID of the Circuit being retrieved.',
+    type=types.NATURAL_KEY,
+    help='Unique ID or natural key of the Circuit being retrieved.',
 )
 @click.option(
     '-l',
@@ -187,6 +192,7 @@ def add(ctx, attributes, endpoint_a, name, site_id, endpoint_z):
     '-Z',
     '--endpoint-z',
     metavar='INTERFACE_ID',
+    type=types.NATURAL_KEY,
     help='Filter to Circuits with endpoint_z interfaces that match this ID'
 )
 @click.pass_context
@@ -257,14 +263,15 @@ def interfaces(ctx, *args, **kwargs):
     '-A',
     '--endpoint-a',
     metavar='INTERFACE_ID',
-    type=int,
-    help='Unique ID of the interface of the A side of the Circuit',
+    type=types.NATURAL_KEY,
+    help='Unique ID or key of the interface of the A side of the Circuit',
 )
 @click.option(
     '-i',
     '--id',
     metavar='ID',
-    help='Unique ID of the Circuit being retrieved.',
+    type=types.NATURAL_KEY,
+    help='Unique ID or natural key of the Circuit being retrieved.',
     required=True,
 )
 @click.option(
@@ -286,8 +293,8 @@ def interfaces(ctx, *args, **kwargs):
     '-Z',
     '--endpoint-z',
     metavar='INTERFACE_ID',
-    type=int,
-    help='Unique ID of the interface on the Z side of the Circuit',
+    type=types.NATURAL_KEY,
+    help='Unique ID or key of the interface on the Z side of the Circuit',
 )
 @click.option(
     '--add-attributes',
@@ -327,6 +334,13 @@ def update(ctx, attributes, endpoint_a, id, name, site_id, endpoint_z,
     You must either have a Site ID configured in your .pysnotrc file or specify
     one using the -s/--site-id option.
 
+    When updating a Circuit you must provide the ID (-i/--id) and at least
+    one of the optional arguments. The ID can either be the numeric ID of the
+    Circuit or the natural key. (Example: lax-r1:ae0_jfk-r2:ae0)
+
+    For the -A/--endpoint-a and -Z/--endpoint-z options, you may provide either
+    the Interface ID or its natural key.
+
     The -a/--attributes option may be provided multiple times, once for each
     key-value pair.
 
@@ -362,7 +376,8 @@ def update(ctx, attributes, endpoint_a, id, name, site_id, endpoint_z,
     '-i',
     '--id',
     metavar='ID',
-    help='Unique ID of the Circuit being deleted.',
+    help='Unique ID or natural key of the Circuit being deleted.',
+    type=types.NATURAL_KEY,
     required=True,
 )
 @click.option(
diff --git a/pynsot/commands/cmd_devices.py b/pynsot/commands/cmd_devices.py
index b1b91f2..b422b3b 100644
--- a/pynsot/commands/cmd_devices.py
+++ b/pynsot/commands/cmd_devices.py
@@ -23,7 +23,7 @@
 # field names oto their human-readable form when calling .print_list().
 DISPLAY_FIELDS = (
     ('id', 'ID'),
-    ('hostname', 'Hostname'),
+    ('hostname', 'Hostname (Key)'),
     # ('site_id': 'Site ID'),
     ('attributes', 'Attributes'),
 )
diff --git a/pynsot/commands/cmd_interfaces.py b/pynsot/commands/cmd_interfaces.py
index 0c95bb1..8ef00e5 100644
--- a/pynsot/commands/cmd_interfaces.py
+++ b/pynsot/commands/cmd_interfaces.py
@@ -17,7 +17,7 @@
 import logging
 
 from ..vendor import click
-from . import callbacks
+from . import callbacks, types
 from .cmd_networks import DISPLAY_FIELDS as NETWORK_DISPLAY_FIELDS
 
 
@@ -28,8 +28,8 @@
 # field names oto their human-readable form when calling .print_list().
 DISPLAY_FIELDS = (
     ('id', 'ID'),
-    ('device_hostname', 'Device'),
-    ('name', 'Name'),
+    ('name_slug', 'Name (Key)'),
+    ('parent', 'Parent'),
     ('mac_address', 'MAC'),
     ('addresses', 'Addresses'),
     ('attributes', 'Attributes'),
@@ -38,14 +38,12 @@
 # Fields to display when viewing a single record.
 VERBOSE_FIELDS = (
     ('id', 'ID'),
-    ('device', 'Device ID'),
-    ('device_hostname', 'Device'),
-    ('name', 'Name'),
+    ('name_slug', 'Name'),
+    ('parent', 'Parent'),
     ('mac_address', 'MAC'),
     ('addresses', 'Addresses'),
     ('speed', 'Speed'),
     ('type', 'Type'),
-    ('parent_id', 'Parent'),
     ('attributes', 'Attributes'),
 )
 
@@ -86,6 +84,7 @@ def cli(ctx):
     '-D',
     '--device',
     metavar='DEVICE',
+    type=types.NATURAL_KEY,
     help=(
         'Unique ID of the Device to which this Interface is '
         'attached.  [required]'
@@ -116,7 +115,7 @@ def cli(ctx):
     '-p',
     '--parent-id',
     metavar='PARENT_ID',
-    type=int,
+    type=types.NATURAL_KEY,
     help='Unique ID of the parent interface.'
 )
 @click.option(
@@ -147,7 +146,7 @@ def add(ctx, attributes, addresses, device, description, mac_address,
     """
     Add a new Interface.
 
-    You must provide a Device ID using the -D/--device option.
+    You must provide a Device hostname or ID using the -D/--device option.
 
     When adding a new Interface, you must provide a value for the -n/--name
     option.
@@ -196,6 +195,7 @@ def add(ctx, attributes, addresses, device, description, mac_address,
     '-D',
     '--device',
     metavar='DEVICE',
+    type=types.NATURAL_KEY,
     help='Unique ID or hostname of the Device being retrieved.',
 )
 @click.option(
@@ -256,7 +256,7 @@ def add(ctx, attributes, addresses, device, description, mac_address,
     '-p',
     '--parent-id',
     metavar='PARENT_ID',
-    type=int,
+    type=types.NATURAL_KEY,
     help='Filter by integer of the ID of the parent Interface.',
 )
 @click.option(
@@ -387,6 +387,7 @@ def root(ctx, *args, **kwargs):
         ctx, display_fields=VERBOSE_FIELDS, my_name=ctx.info_name
     )
 
+
 @list.command()
 @click.pass_context
 def siblings(ctx, *args, **kwargs):
@@ -395,6 +396,7 @@ def siblings(ctx, *args, **kwargs):
         ctx, display_fields=VERBOSE_FIELDS, my_name=ctx.info_name
     )
 
+
 ASSIGNMENT_FIELDS = (
     ('id', 'ID'),
     ('hostname', 'Device'),
@@ -491,6 +493,7 @@ def remove(ctx, id, site_id):
     '-i',
     '--id',
     metavar='ID',
+    type=types.NATURAL_KEY,
     help='Unique ID of the Interface being updated.',
     required=True,
 )
@@ -512,7 +515,7 @@ def remove(ctx, id, site_id):
     '-p',
     '--parent-id',
     metavar='PARENT_ID',
-    type=int,
+    type=types.NATURAL_KEY,
     help='Unique ID of the parent interface.',
 )
 @click.option(
diff --git a/pynsot/commands/cmd_networks.py b/pynsot/commands/cmd_networks.py
index 664beac..02b6a01 100644
--- a/pynsot/commands/cmd_networks.py
+++ b/pynsot/commands/cmd_networks.py
@@ -23,12 +23,10 @@
 # field names oto their human-readable form when calling .print_list().
 DISPLAY_FIELDS = (
     ('id', 'ID'),
-    ('network_address', 'Network'),
-    ('prefix_length', 'Prefix'),
-    # ('site_id': 'Site ID'),
+    ('cidr', 'CIDR (Key)'),
     ('is_ip', 'Is IP?'),
     ('ip_version', 'IP Ver.'),
-    ('parent_id', 'Parent ID'),
+    ('parent', 'Parent'),
     ('state', 'State'),
     ('attributes', 'Attributes'),
 )
diff --git a/pynsot/commands/types.py b/pynsot/commands/types.py
index 7d80b55..03df331 100644
--- a/pynsot/commands/types.py
+++ b/pynsot/commands/types.py
@@ -36,4 +36,36 @@ def convert(self, value, param, ctx):
     def __repr__(self):
         return 'NETWORK_ID'
 
+
+class NaturalKeyParamType(click.ParamType):
+    """Custom paramer type that supports ID or natural key."""
+    name = 'natural key'
+
+    def convert(self, value, param, ctx):
+        if value is None:
+            return
+
+        tests = [int, str]
+        win = False
+        for test in tests:
+            try:
+                win = test(value)
+            except:
+                pass
+            else:
+                if not win:
+                    continue
+                return value
+
+        else:
+            self.fail(
+                '%s is not an valid integer or natural key' % value, param, ctx
+            )
+
+    def __repr__(self):
+        return 'NATURAL_KEY'
+
+
+# Constants for these types
 NETWORK_ID = NetworkIdParamType()
+NATURAL_KEY = NaturalKeyParamType()
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 753bd3c..730c9ec 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,8 +1,9 @@
 -r requirements.txt
 fake-factory~=0.5.0
+flake8~=3.3.0
 ipdb~=0.9.3
 ipython~=5.0
-nsot>=1.1.4,~=1.1.0
+nsot>=1.2.0,~=1.2.0
 py~=1.4.26,>=1.4.29
 pytest~=2.7.0
 pytest-django~=2.9.1
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..406bfc3
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,2 @@
+[flake8]
+exclude = tests/*,docs
diff --git a/tests/app/test_circuits.py b/tests/app/test_circuits.py
index 6a4e142..dda7bd4 100644
--- a/tests/app/test_circuits.py
+++ b/tests/app/test_circuits.py
@@ -7,6 +7,8 @@
 from __future__ import absolute_import, unicode_literals
 import logging
 
+import pytest
+
 from tests.fixtures import (attribute, attributes, client, config, device,
                             interface, network, runner, site, site_client)
 from tests.fixtures.circuits import (circuit, circuit_attributes, device_a,
@@ -62,7 +64,7 @@ def test_circuits_add_intf_reuse(runner, interface_a):
 
         result = runner.run(cmd.format(interface_a['id'], 'bad_circuit'))
         assert result.exit_code != 0
-        assert 'endpoint_a:  This field must be unique' in result.output
+        assert 'A-side endpoint Interface already exists' in result.output
 
 
 def test_circuits_add_dupe_name(runner, interface_a, interface_z):
diff --git a/tests/test_app.py b/tests/test_app.py
index a3547f8..b49e01b 100644
--- a/tests/test_app.py
+++ b/tests/test_app.py
@@ -586,7 +586,7 @@ def test_networks_list(site_client):
         # Make sure 10.0.0.0 shows twice in the output. Lazy man's output
         # checking.
         result = runner.run('networks list')
-        assert result.output.count('10.0.0.0') == 2
+        assert result.output.count('10.0.0.0') == 3
         assert result.exit_code == 0
 
         # Set query display newline-delimited (default)
@@ -970,9 +970,9 @@ def test_interfaces_list(site_client, device):
         assert result.output == expected_output
 
         # Query by natural key
-        result = runner.run('interfaces list -i {0}:eth1'.format(hostname))
-        assert 'eth1' in result.output
-        assert str(device_id) in result.output
+        natural_key = '{0}:eth1'.format(hostname)
+        result = runner.run('interfaces list -i {}'.format(natural_key))
+        assert natural_key in result.output
         assert result.exit_code == 0
 
         ###########