diff --git a/README.md b/README.md
index ba096f7..0b66930 100644
--- a/README.md
+++ b/README.md
@@ -18,15 +18,18 @@ This repository interfaces Service Discovery, in this instance CloudMap, in orde
 
 
 ## TODO
-- Lambda (`request`).
 - SQS (`listen`).
 - Http (`request`|`call`).
 - Fargate/ECS Task (`run`).
+- Lambda (`request`).
+
+
+## Note
 
-## Note:
 This library requires *Python 3.5 and above*.
 
-## Examples:
+
+## Examples
 
 ### Lambda Call
 
@@ -43,3 +46,14 @@ from ais_service_discovery import call
 response=call('namespace', 'service', 'handler', {<Payload>}, {'InvocationType': 'Event'})
 print(response)
 ```
+
+## Configuration
+
+This library can utilise the following environment variables:
+
+```
+BOTO_MAX_ATTEMPTS=10 // Boto3 exponential back-off attemps
+BOTO_READ_TIMEOUT=300 // Boto3 timeout 
+BOTO_CONNECTION_TIMEOUT=60 // Boto3 connection timeout
+```
+
diff --git a/ais_service_discovery/call_service.py b/ais_service_discovery/call_service.py
index 39bef3a..4af3df1 100644
--- a/ais_service_discovery/call_service.py
+++ b/ais_service_discovery/call_service.py
@@ -1,15 +1,35 @@
+"""
+call_service
+
+Calls services via the service discovery library
+"""
+from os import environ as env
+from json import dumps
+
 from boto3 import client
-from .services import default_namespace, extract_service_parts, Services, \
+from botocore.config import Config
+
+from .services import default_namespace, Services, \
     CloudmapAdapter
 from .functions import LambdaAdaptor, Func
 from .sns import SnsAdaptor, Publish
 from .sqs import SqsAdaptor, Send
-from json import dumps
 
-function = client('lambda')
-sns = client('sns')
-sqs = client('sqs')
-service_discovery = client('servicediscovery')
+
+BOTO_MAX_ATTEMPTS = int(env.get('BOTO_MAX_ATTEMPTS', 1))
+BOTO_READ_TIMEOUT = float(env.get('BOTO_READ_TIMEOUT', 5))
+BOTO_CONNECTION_TIMEOUT = float(env.get('BOTO_CONNECTION_TIMEOUT', 60))
+
+config = Config(
+    read_timeout=BOTO_READ_TIMEOUT,
+    retries={'total_max_attempts': BOTO_MAX_ATTEMPTS},
+    connect_timeout=BOTO_CONNECTION_TIMEOUT
+)
+
+function = client('lambda', config=config)
+sns = client('sns', config=config)
+sqs = client('sqs', config=config)
+service_discovery = client('servicediscovery', config=config)
 
 cloudmap_adaptor = CloudmapAdapter(service_discovery)
 services = Services(cloudmap_adaptor)
@@ -23,9 +43,11 @@
 sqs_adaptor = SqsAdaptor(sqs)
 send = Send(sqs_adaptor)
 
+
 def run_service(service, body, opts={}):
-    type = service['Attributes']['type']
-    if type in ['cloud-function', 'function', 'lambda']:
+    """ run_service """
+    service_type = service['Attributes']['type']
+    if service_type in ['cloud-function', 'function', 'lambda']:
         return func.call(**{
             'FunctionName': service['Attributes']['arn'],
             'Payload': dumps(body),
@@ -47,6 +69,7 @@ def run_service(service, body, opts={}):
 
 
 def call_service(namespace, service, handler, body, opts={}):
+    """ call_service """
     instances = services.discover(
         namespace or default_namespace(), service, handler)['Instances']
     if not instances:
@@ -54,7 +77,7 @@ def call_service(namespace, service, handler, body, opts={}):
             namespace or default_namespace(), service, handler))
     [service_to_run] = instances
     payload = run_service(service_to_run, body, opts)
-    if (payload and type(payload) is dict and
+    if (payload and isinstance(payload, dict) and
             ('errorMessage' in payload) and ('errorMessage' in payload)):
         raise Exception(payload)
     return dumps(payload)
diff --git a/ais_service_discovery/services/cloudmap.py b/ais_service_discovery/services/cloudmap.py
index 00c722a..7967a7b 100644
--- a/ais_service_discovery/services/cloudmap.py
+++ b/ais_service_discovery/services/cloudmap.py
@@ -4,10 +4,10 @@ def __init__(self, client):
 
     def filter_instances(self, response, id):
         filter_function = lambda instance : instance['InstanceId'] == id
-
+        
         return {
             **response,
-            'Instances': filter(filter_function, response['Instances'])
+            'Instances': list(filter(filter_function, response['Instances']))
         }
 
     def discover(self, namespace, name, id):
@@ -15,3 +15,4 @@ def discover(self, namespace, name, id):
             NamespaceName=namespace,
             ServiceName=name
         ), id)
+
diff --git a/examples.py b/examples.py
new file mode 100644
index 0000000..ab3b815
--- /dev/null
+++ b/examples.py
@@ -0,0 +1,13 @@
+from ais_service_discovery import call
+
+try:
+    res = call(
+        'my-namespace',
+        'my-service',
+        'my-instance', {
+            'arg': 'hello-word',
+    })
+    print(res)
+except Exception as e:
+    print(e)
+
diff --git a/setup.py b/setup.py
index f7c44f8..cddee63 100644
--- a/setup.py
+++ b/setup.py
@@ -8,7 +8,7 @@
 
 setup(
     name='ais_service_discovery',
-    version='0.2.0',
+    version='0.2.1-rc7',
     author='Peak AI',
     author_email='infra-notifications@peak.ai',
     description='AIS service discovery package for python3',