diff --git a/src/Web/Stripe/Client.hs b/src/Web/Stripe/Client.hs
--- a/src/Web/Stripe/Client.hs
+++ b/src/Web/Stripe/Client.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE OverloadedStrings  #-}
 -- |
 -- Module      : Web.Stripe.Client
 -- Copyright   : (c) David Johnson, 2014
@@ -13,6 +14,9 @@
     , parseFail
     , attemptDecode
     , unknownCode
+    , defaultEndpoint
+    , Endpoint      (..)
+    , Protocol      (..)
     , StripeConfig  (..)
     , StripeKey     (..)
     , APIVersion    (..)
@@ -37,10 +41,28 @@
     } deriving (Read, Show, Eq, Ord, Data, Typeable)
 
 ------------------------------------------------------------------------------
+-- | Endpoint Protocol
+data Protocol = HTTP | HTTPS
+  deriving (Read, Show, Eq, Ord, Data, Typeable)
+
+------------------------------------------------------------------------------
 -- | Stripe config
 data StripeConfig = StripeConfig
     { secretKey :: StripeKey
+    , stripeEndpoint :: Maybe Endpoint
     } deriving (Read, Show, Eq, Ord, Data, Typeable)
+
+------------------------------------------------------------------------------
+-- | Stripe endpoint, useful for mocking
+data Endpoint
+  = Endpoint
+  { endpointUrl :: ByteString
+  , endpointProtocol :: Protocol
+  , endpointPort :: Int
+  } deriving (Show, Eq, Read, Ord, Data)
+
+defaultEndpoint :: Endpoint
+defaultEndpoint = Endpoint "api.stripe.com" HTTPS 443
 
 ------------------------------------------------------------------------------
 -- | API Version
diff --git a/src/Web/Stripe/Invoice.hs b/src/Web/Stripe/Invoice.hs
--- a/src/Web/Stripe/Invoice.hs
+++ b/src/Web/Stripe/Invoice.hs
@@ -149,6 +149,7 @@
 instance StripeHasParam GetInvoices ExpandParams
 instance StripeHasParam GetInvoices (EndingBefore InvoiceId)
 instance StripeHasParam GetInvoices Limit
+instance StripeHasParam GetInvoices CustomerId
 instance StripeHasParam GetInvoices (StartingAfter InvoiceId)
 
 ------------------------------------------------------------------------------
diff --git a/src/Web/Stripe/InvoiceItem.hs b/src/Web/Stripe/InvoiceItem.hs
--- a/src/Web/Stripe/InvoiceItem.hs
+++ b/src/Web/Stripe/InvoiceItem.hs
@@ -164,3 +164,4 @@
 instance StripeHasParam GetInvoiceItems (EndingBefore InvoiceItemId)
 instance StripeHasParam GetInvoiceItems Limit
 instance StripeHasParam GetInvoiceItems (StartingAfter InvoiceItemId)
+instance StripeHasParam GetInvoiceItems InvoiceId
diff --git a/src/Web/Stripe/Types.hs b/src/Web/Stripe/Types.hs
--- a/src/Web/Stripe/Types.hs
+++ b/src/Web/Stripe/Types.hs
@@ -6,7 +6,7 @@
 {-# LANGUAGE TypeFamilies         #-}
 {-# LANGUAGE UndecidableInstances #-}
 ------------------------------------------------------------------------------
--- | 
+-- |
 -- Module      : Web.Stripe.Types
 -- Copyright   : (c) David Johnson, 2014
 -- Maintainer  : djohnson.m@gmail.com
@@ -21,6 +21,7 @@
 import           Data.Aeson          (FromJSON (parseJSON), ToJSON(..),
                                       Value (String, Object, Bool), (.:),
                                       (.:?))
+import           Data.Aeson.Types    (typeMismatch)
 import           Data.Data           (Data, Typeable)
 import qualified Data.HashMap.Strict as H
 import           Data.Ratio          ((%))
@@ -196,7 +197,7 @@
     , refundCreated            :: UTCTime
     , refundObject             :: Text
     , refundCharge             :: ChargeId
-    , refundBalanceTransaction :: Expandable TransactionId
+    , refundBalanceTransaction :: Maybe (Expandable TransactionId)
     , refundMetaData           :: MetaData
     } deriving (Read, Show, Eq, Ord, Data, Typeable)
 
@@ -210,7 +211,7 @@
                <*> (fromSeconds <$> o .: "created")
                <*> o .: "object"
                <*> o .: "charge"
-               <*> o .: "balance_transaction"
+               <*> o .:? "balance_transaction"
                <*> o .: "metadata"
    parseJSON _ = mzero
 
@@ -250,7 +251,7 @@
     , customerDescription    :: Maybe Description
     , customerEmail          :: Maybe Email
     , customerDelinquent     :: Bool
-    , customerSubscriptions  :: StripeList Subscription
+    , customerSubscriptions  :: Maybe (StripeList Subscription)
     , customerDiscount       :: Maybe Discount
     , customerAccountBalance :: Int
     , customerCards          :: StripeList Card
@@ -258,15 +259,18 @@
     , customerDefaultCard    :: Maybe (Expandable CardId)
     , customerMetaData       :: MetaData
     } | DeletedCustomer {
-      deletedCustomer   :: Maybe Bool
+      deletedCustomer   :: Bool
     , deletedCustomerId :: CustomerId
   } deriving (Read, Show, Eq, Ord, Data, Typeable)
 
 ------------------------------------------------------------------------------
 -- | JSON Instance for `Customer`
 instance FromJSON Customer where
-    parseJSON (Object o)
-        = (Customer
+  parseJSON (Object o)
+        = (DeletedCustomer
+           <$> o .: "deleted"
+           <*> (CustomerId <$> o .: "id"))
+           <|> (Customer
            <$> o .: "object"
            <*> (fromSeconds <$> o .: "created")
            <*> (CustomerId <$> o .: "id")
@@ -274,20 +278,14 @@
            <*> o .:? "description"
            <*> (fmap Email <$> o .:? "email")
            <*> o .: "delinquent"
-           <*> o .: "subscriptions"
+           <*> o .:? "subscriptions"
            <*> o .:? "discount"
            <*> o .: "account_balance"
            <*> o .: "cards"
            <*> o .:? "currency"
            <*> o .:? "default_card"
-           <*> o .: "metadata"
-           <|> DeletedCustomer
-           <$> o .: "deleted"
-           <*> (CustomerId <$> o .: "id"))
-           <|> DeletedCustomer
-           <$> o .:? "deleted"
-           <*> (CustomerId <$> o .: "id")
-    parseJSON _ = mzero
+           <*> o .: "metadata")
+  parseJSON o = typeMismatch "Customer" o
 
 ------------------------------------------------------------------------------
 -- | AccountBalance for a `Customer`
@@ -393,7 +391,7 @@
     , cardFunding           :: Text
     , cardExpMonth          :: ExpMonth
     , cardExpYear           :: ExpYear
-    , cardFingerprint       :: Text
+    , cardFingerprint       :: Maybe Text
     , cardCountry           :: Maybe Text
     , cardName              :: Maybe Name
     , cardAddressLine1      :: Maybe AddressLine1
@@ -444,7 +442,7 @@
              <*> o .: "funding"
              <*> (ExpMonth <$> o .: "exp_month")
              <*> (ExpYear <$> o .: "exp_year")
-             <*> o .: "fingerprint"
+             <*> o .:? "fingerprint"
              <*> o .:? "country"
              <*> o .:? "name"
              <*> (fmap AddressLine1 <$> o .:? "address_line1")
@@ -1733,7 +1731,7 @@
    parseJSON (String "application_fee.refunded") = pure ApplicationFeeRefundedEvent
    parseJSON (String "balance.available") = pure BalanceAvailableEvent
    parseJSON (String "charge.succeeded") = pure ChargeSucceededEvent
-   parseJSON (String "chage.failed") = pure ChargeFailedEvent
+   parseJSON (String "charge.failed") = pure ChargeFailedEvent
    parseJSON (String "charge.refunded") = pure ChargeRefundedEvent
    parseJSON (String "charge.captured") = pure ChargeCapturedEvent
    parseJSON (String "charge.updated") = pure ChargeUpdatedEvent
diff --git a/stripe-core.cabal b/stripe-core.cabal
--- a/stripe-core.cabal
+++ b/stripe-core.cabal
@@ -1,5 +1,5 @@
 name:                stripe-core
-version:             2.4.1
+version:             2.5.0
 synopsis:            Stripe API for Haskell - Pure Core
 license:             MIT
 license-file:        LICENSE
@@ -16,7 +16,7 @@
     <<https://stripe.com/img/navigation/logo@2x.png>>
     .
     [Pure API Wrapper]
-    `stripe-core` provides a complete binding to the Stripe API. `stripe-core` provides pure wrappers around all the Stripe API objects and methods. `stripe-core` is pure and is not tied to any particular HTTP client library. End users will typically install the `stripe-haskell` package which pulls in the `stripe-http-streams` library to obtain a complete set of functionality.
+    `stripe-core` provides a complete binding to the Stripe API. `stripe-core` provides pure wrappers around all the Stripe API objects and methods. `stripe-core` is pure and is not tied to any particular HTTP client library. End users will typically install the `stripe-haskell` package which pulls in the `stripe-http-client` library to obtain a complete set of functionality.
 
 library
   hs-source-dirs:      src