diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,9 +1,10 @@
-reddit for haskell [![Build Status](https://travis-ci.org/intolerable/reddit.svg?branch=master)](https://travis-ci.org/intolerable/reddit)
+reddit for haskell [![CircleCI](https://circleci.com/gh/intolerable/reddit.svg?style=svg)](https://circleci.com/gh/intolerable/reddit)
 ---
 
 A Haskell library for interacting with the [Reddit API](http://reddit.com/api).
 
-### A couple of examples
+A couple of examples
+---
 
 Let's get all the posts from the frontpage of Reddit and write a summary of each of them to the console:
 
@@ -67,8 +68,14 @@
 
 `cabal test test-io`
 
-The `test` test suite will run the tests that don't rely on doing any IO, but the `test-io` should be used too to ensure that IO functions do what they're supposed to do. If you want to run the IO suite, add a file `test.cfg` to the `reddit/` directory, containing (one field per line):
+The `test` test suite will run the tests that don't rely on doing any IO, but the `test-io` should be used too to ensure that IO functions do what they're supposed to do. If you want to run the IO suite, add a file `test_config.yaml` to the `reddit/` directory, like this:
 
-- a reddit username
-- a reddit password
-- a subreddit name (the user should be a moderator for the subredit)
+```
+username: my_reddit_username
+password: my_reddit_password
+subreddit: test_subreddit # A subreddit that the user has moderator access to
+client_id: MY_CLIENT_ID # Your reddit app client ID
+client_secret: MY_CLIENT_SECRET # Your reddit app client secret
+```
+
+Your app client and secret can be found in [your reddit preferences](https://reddit.com/prefs/apps/)
diff --git a/reddit.cabal b/reddit.cabal
--- a/reddit.cabal
+++ b/reddit.cabal
@@ -1,11 +1,11 @@
--- This file has been generated from package.yaml by hpack version 0.20.0.
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.34.4.
 --
 -- see: https://github.com/sol/hpack
---
--- hash: 6d0965ca6f31dbbd95562eb8028178c6142b8dc8d08ddaf93ef114725e63d3fd
 
 name:           reddit
-version:        0.2.3.0
+version:        0.3.0.0
 synopsis:       Library for interfacing with Reddit's API
 description:    A library for interfacing with Reddit''s API in Haskell. Handles logins, rate-limiting and converting to and from JSON responses. Supports most user-facing Reddit API functions, as well as some moderator endpoints. Check out the readme at <https://github.com/intolerable/reddit>.
                 Contributions are welcome.
@@ -18,39 +18,17 @@
 license:        BSD2
 license-file:   LICENSE
 build-type:     Simple
-cabal-version:  >= 1.10
-
 extra-source-files:
     README.md
     test/data/aboutMe_example.json
-    test/data/getUserComments_example.json
     test/data/getUserInfo_example.json
+    test/data/getUserComments_example.json
 
 source-repository head
   type: git
   location: https://github.com/intolerable/reddit
 
 library
-  hs-source-dirs:
-      src
-  default-extensions: FlexibleInstances GADTs GeneralizedNewtypeDeriving LambdaCase OverloadedStrings
-  ghc-options: -Wall -fno-warn-dodgy-imports
-  build-depends:
-      aeson >=0.9 && <1.3
-    , api-builder >=0.10 && <0.16
-    , base >=4.6 && <4.12
-    , bytestring ==0.10.*
-    , data-default-class >=0.0.1 && <0.2
-    , free >=4 && <6
-    , http-client >=0.4.30 && <0.6
-    , http-client-tls >=0.2 && <0.4
-    , http-types >=0.8 && <0.13
-    , network ==2.6.*
-    , text ==1.*
-    , time >=1.5 && <1.9
-    , transformers >=0.4 && <0.6
-    , unordered-containers >=0.2.5 && <0.3
-    , vector >=0.10 && <0.13
   exposed-modules:
       Reddit
       Reddit.Actions
@@ -102,15 +80,55 @@
       Reddit.Types.Empty
       Reddit.Utilities
       Paths_reddit
+  hs-source-dirs:
+      src
+  default-extensions:
+      FlexibleInstances
+      GADTs
+      GeneralizedNewtypeDeriving
+      LambdaCase
+      OverloadedStrings
+      OverloadedStrings
+  ghc-options: -Wall -Wcompat -fno-warn-dodgy-imports
+  build-depends:
+      aeson >=2
+    , api-builder >=0.10
+    , base >=4.6
+    , bytestring >=0.10.8
+    , data-default-class >=0.0.1
+    , free >=4
+    , http-client >=0.4.30
+    , http-client-tls >=0.2
+    , http-types >=0.8
+    , network >=2.6
+    , text >=1.2
+    , time >=1.5
+    , transformers >=0.4
+    , unordered-containers >=0.2.5
+    , vector >=0.10
   default-language: Haskell2010
 
 test-suite test
   type: exitcode-stdio-1.0
   main-is: Spec.hs
+  other-modules:
+      Reddit.Types.CommentSpec
+      Reddit.Types.ListingSpec
+      Reddit.Types.PostSpec
+      Reddit.Types.SubredditSpec
+      Reddit.Types.UserSpec
+      Reddit.Types.WikiSpec
+      Paths_reddit
   hs-source-dirs:
       test
-  default-extensions: FlexibleInstances GADTs GeneralizedNewtypeDeriving LambdaCase OverloadedStrings
-  ghc-options: -Wall
+  default-extensions:
+      FlexibleInstances
+      GADTs
+      GeneralizedNewtypeDeriving
+      LambdaCase
+      OverloadedStrings
+      OverloadedStrings
+  ghc-options: -Wall -Wcompat
   build-depends:
       Cabal >=1.16.0
     , aeson
@@ -122,24 +140,34 @@
     , text
     , time
     , transformers
-  other-modules:
-      Reddit.Types.CommentSpec
-      Reddit.Types.ListingSpec
-      Reddit.Types.PostSpec
-      Reddit.Types.SubredditSpec
-      Reddit.Types.UserSpec
-      Reddit.Types.WikiSpec
-      Paths_reddit
   default-language: Haskell2010
 
 test-suite test-anon
   type: exitcode-stdio-1.0
   main-is: Spec.hs
+  other-modules:
+      Reddit.Actions.CaptchaSpec
+      Reddit.Actions.CommentSpec
+      Reddit.Actions.FlairSpec
+      Reddit.Actions.MessageSpec
+      Reddit.Actions.PostSpec
+      Reddit.Actions.SearchSpec
+      Reddit.Actions.SubredditSpec
+      Reddit.Actions.UserSpec
+      Utils
+      Paths_reddit
   hs-source-dirs:
       test-anon
       test-utils
-  default-extensions: FlexibleInstances GADTs GeneralizedNewtypeDeriving LambdaCase OverloadedStrings Rank2Types
-  ghc-options: -Wall
+  default-extensions:
+      FlexibleInstances
+      GADTs
+      GeneralizedNewtypeDeriving
+      LambdaCase
+      OverloadedStrings
+      OverloadedStrings
+      Rank2Types
+  ghc-options: -Wall -Wcompat
   build-depends:
       Cabal >=1.16.0
     , api-builder
@@ -150,33 +178,42 @@
     , text
     , time
     , transformers
+  default-language: Haskell2010
+
+test-suite test-io
+  type: exitcode-stdio-1.0
+  main-is: Spec.hs
   other-modules:
+      ConfigLoad
       Reddit.Actions.CaptchaSpec
       Reddit.Actions.CommentSpec
       Reddit.Actions.FlairSpec
       Reddit.Actions.MessageSpec
       Reddit.Actions.PostSpec
-      Reddit.Actions.SearchSpec
       Reddit.Actions.SubredditSpec
       Reddit.Actions.UserSpec
       Utils
       Paths_reddit
-  default-language: Haskell2010
-
-test-suite test-io
-  type: exitcode-stdio-1.0
-  main-is: Spec.hs
   hs-source-dirs:
       test-io
       test-utils
-  default-extensions: FlexibleInstances GADTs GeneralizedNewtypeDeriving LambdaCase OverloadedStrings Rank2Types
-  ghc-options: -Wall
+  default-extensions:
+      FlexibleInstances
+      GADTs
+      GeneralizedNewtypeDeriving
+      LambdaCase
+      OverloadedStrings
+      OverloadedStrings
+      Rank2Types
+      RecordWildCards
+  ghc-options: -Wall -Wcompat
   build-depends:
       Cabal >=1.16.0
     , api-builder
     , base ==4.*
     , bytestring
     , data-default-class
+    , directory
     , hspec
     , http-client
     , http-client-tls
@@ -185,15 +222,4 @@
     , time
     , transformers
     , yaml
-  other-modules:
-      ConfigLoad
-      Reddit.Actions.CaptchaSpec
-      Reddit.Actions.CommentSpec
-      Reddit.Actions.FlairSpec
-      Reddit.Actions.MessageSpec
-      Reddit.Actions.PostSpec
-      Reddit.Actions.SubredditSpec
-      Reddit.Actions.UserSpec
-      Utils
-      Paths_reddit
   default-language: Haskell2010
diff --git a/src/Reddit.hs b/src/Reddit.hs
--- a/src/Reddit.hs
+++ b/src/Reddit.hs
@@ -33,7 +33,7 @@
 import Data.ByteString.Char8 (ByteString)
 import Data.Default.Class
 import Data.Maybe (fromMaybe, isNothing)
-import Data.Monoid
+import Data.Semigroup ((<>))
 import Data.Text (Text)
 import Data.Text.Encoding (encodeUtf8)
 import Data.Version
@@ -41,6 +41,7 @@
 import Network.HTTP.Client
 import Network.HTTP.Client.TLS
 import Network.HTTP.Types
+import Prelude hiding ((<>))
 import qualified Data.ByteString.Char8 as BS
 
 import qualified Paths_reddit
@@ -79,7 +80,7 @@
 -- | Should we log in to Reddit? If so, should we use a stored set of credentials
 --   or get a new fresh set?
 data LoginMethod = Anonymous -- ^ Don't login, instead use an anonymous account
-                 | Credentials Text Text -- ^ Login using the specified username and password
+                 | Credentials Text Text ClientParams-- ^ Login using the specified username and password
                  | StoredDetails LoginDetails -- ^
                  --   Login using a stored set of credentials. Usually the best way to get
                  --   these is to do @'runRedditAnon' $ 'login' user pass@.
@@ -91,8 +92,8 @@
 --   for 'RedditOptions': rate limiting enabled, default manager, login via username and password, and
 --   the default user-agent. You should change the user agent if you're making anything more complex than
 --   a basic script, since Reddit's API policy says that you should have a uniquely identifiable user agent.
-runReddit :: MonadIO m => Text -> Text -> RedditT m a -> m (Either (APIError RedditError) a)
-runReddit user pass = runRedditWith def { loginMethod = Credentials user pass }
+runReddit :: MonadIO m => Text -> Text -> ClientParams -> RedditT m a -> m (Either (APIError RedditError) a)
+runReddit user pass cp = runRedditWith def { loginMethod = Credentials user pass cp }
 
 -- | Run a 'Reddit' action (or a 'RedditT' transformer action). This uses the default logged-out settings, so
 --   you won't be able to do anything that requires authentication (like checking messages or making a post).
@@ -119,7 +120,7 @@
   loginCreds <- case lm of
     Anonymous -> return $ Right Nothing
     StoredDetails ld -> return $ Right $ Just ld
-    Credentials user pass -> liftM (fmap Just) $ interpretIO (RedditState loginBaseURL rl manager [] Nothing) $ login user pass
+    Credentials user pass cp -> liftM (fmap Just) $ interpretIO (RedditState loginBaseURL rl manager [] Nothing) $ login user pass cp
   case loginCreds of
     Left (err, _) -> return $ Left (err, Just reddit)
     Right lds ->
@@ -136,6 +137,12 @@
           return $ Left (err, Just $ resume >>= RedditT . n)
         Left (err, Nothing) -> return $ Left (err, Nothing)
         Right res -> interpretIO rstate $ RedditT $ n res
+    Free (WithHeaders hf x n) -> do
+      interpretIO (rstate { extraHeaders = hf (extraHeaders rstate)}) x >>= \case
+        Left (err, Just resume) ->
+          return $ Left (err, Just $ resume >>= RedditT . n)
+        Left (err, Nothing) -> return $ Left (err, Nothing)
+        Right res -> interpretIO rstate $ RedditT $ n res
     Free (FailWith x) -> return $ Left (x, Nothing)
     Free (Nest x n) ->
       interpretIO rstate $ RedditT $ wrap $ NestResuming x (n . dropResume)
@@ -179,7 +186,7 @@
   RedditState { currentBaseURL :: Text
               , rateLimit :: Bool
               , connMgr :: Manager
-              , _extraHeaders :: [Header]
+              , extraHeaders :: [Header]
               , _creds :: Maybe LoginDetails }
 
 customUAWarning :: MonadIO m => m ()
diff --git a/src/Reddit/Actions/User.hs b/src/Reddit/Actions/User.hs
--- a/src/Reddit/Actions/User.hs
+++ b/src/Reddit/Actions/User.hs
@@ -85,5 +85,5 @@
 setUserFlair :: Monad m => SubredditName -> Username -> Text -> Text -> RedditT m ()
 setUserFlair r u txt cls =
   if Text.length txt > 64
-    then fail "Flair text too long!"
+    then failWith $ APIError FlairTooLong
     else nothing $ runRoute $ Route.setUserFlair r u txt cls
diff --git a/src/Reddit/Login.hs b/src/Reddit/Login.hs
--- a/src/Reddit/Login.hs
+++ b/src/Reddit/Login.hs
@@ -13,12 +13,13 @@
                              , "passwd" =. pass ]
                              "POST"
 
-getLoginDetails :: Monad m => Text -> Text -> RedditT m LoginDetails
-getLoginDetails user pass = receiveRoute $ loginRoute user pass
+getLoginDetails :: Monad m => Text -> Text -> ClientParams -> RedditT m LoginDetails
+getLoginDetails user pass cp = withHeaders (mkClientParamsHeader cp :) $ receiveRoute $ loginRoute user pass
 
 -- | Make a login request with the given username and password.
 login :: Monad m
       => Text -- ^ Username to login with
       -> Text -- ^ Password to login with
+      -> ClientParams
       -> RedditT m LoginDetails
 login = getLoginDetails
diff --git a/src/Reddit/Types/Empty.hs b/src/Reddit/Types/Empty.hs
--- a/src/Reddit/Types/Empty.hs
+++ b/src/Reddit/Types/Empty.hs
@@ -5,7 +5,7 @@
 import Data.Aeson.Types
 import Data.Monoid
 import Prelude
-import qualified Data.HashMap.Strict as Hash
+import qualified Data.Aeson.KeyMap as KeyMap
 
 -- | More specific @void@ for forcing a @Empty@ @FromJSON@ instance
 nothing :: Monad m => m Empty -> m ()
@@ -16,7 +16,7 @@
 
 instance FromJSON Empty where
   parseJSON (Object o) =
-    if Hash.null o
+    if KeyMap.null o
       then return Empty
       else do
         errs <- (o .: "json") >>= (.: "errors") :: Parser [Value]
diff --git a/src/Reddit/Types/Error.hs b/src/Reddit/Types/Error.hs
--- a/src/Reddit/Types/Error.hs
+++ b/src/Reddit/Types/Error.hs
@@ -25,6 +25,7 @@
                  | LinkDeleted
                  | BadSubredditName
                  | TooManyRequests
+                 | FlairTooLong
                  deriving (Show, Eq)
 
 instance FromJSON RedditError where
diff --git a/src/Reddit/Types/Listing.hs b/src/Reddit/Types/Listing.hs
--- a/src/Reddit/Types/Listing.hs
+++ b/src/Reddit/Types/Listing.hs
@@ -5,7 +5,7 @@
 import Control.Applicative
 import Data.Aeson
 import Data.Traversable
-import Data.Monoid
+import Data.Semigroup
 import Network.API.Builder.Query
 import Prelude
 
@@ -32,9 +32,12 @@
 instance Functor (Listing t) where
   fmap f (Listing b a x) = Listing b a (fmap f x)
 
-instance Ord t => Monoid (Listing t a) where
-  mappend (Listing a b cs) (Listing d e fs) =
+instance Ord t => Semigroup (Listing t a) where
+  Listing a b cs <> Listing d e fs =
     Listing (max a d) (min b e) (cs <> fs)
+
+instance Ord t => Monoid (Listing t a) where
+  mappend = (<>)
   mempty = Listing Nothing Nothing []
 
 instance (FromJSON t, FromJSON a) => FromJSON (Listing t a) where
diff --git a/src/Reddit/Types/Reddit.hs b/src/Reddit/Types/Reddit.hs
--- a/src/Reddit/Types/Reddit.hs
+++ b/src/Reddit/Types/Reddit.hs
@@ -7,6 +7,7 @@
   , nest
   , failWith
   , withBaseURL
+  , withHeaders
   , Modhash(..)
   , LoginDetails(..)
   , POSTWrapped(..)
@@ -14,9 +15,12 @@
   , RateLimits(RateLimits, should, info)
   , RateLimitInfo(..)
   , headersToRateLimitInfo
+  , ClientParams(..)
+  , mkClientParamsHeader
   , mainBaseURL
   , loginBaseURL
-  , addAPIType ) where
+  , addAPIType
+  ) where
 
 import Reddit.Types.Error
 
@@ -35,6 +39,7 @@
 import Prelude
 import Text.Read (readMaybe)
 import qualified Data.ByteString.Char8 as BS
+import qualified Data.Text.Encoding as Text
 
 type Reddit a = RedditT IO a
 
@@ -45,6 +50,7 @@
   ReceiveRoute :: Receivable b => Route -> (b -> a) -> RedditF m a
   RunRoute :: FromJSON b => Route -> (b -> a) -> RedditF m a
   WithBaseURL :: Text -> RedditT m b -> (b -> a) -> RedditF m a
+  WithHeaders :: ([Header] -> [Header]) -> RedditT m b -> (b -> a) -> RedditF m a
 
 instance Functor (RedditF m) where
   fmap _ (FailWith x) = FailWith x
@@ -53,6 +59,7 @@
   fmap f (ReceiveRoute r x) = ReceiveRoute r (fmap f x)
   fmap f (RunRoute r x) = RunRoute r (fmap f x)
   fmap f (WithBaseURL u a x) = WithBaseURL u a (fmap f x)
+  fmap f (WithHeaders hf a x) = WithHeaders hf a (fmap f x)
 
 newtype RedditT m a = RedditT (FreeT (RedditF m) m a)
   deriving (Functor, Applicative, Monad)
@@ -75,6 +82,9 @@
 withBaseURL :: Monad m => Text -> RedditT m a -> RedditT m a
 withBaseURL u f = RedditT $ liftF $ WithBaseURL u f id
 
+withHeaders :: Monad m => ([Header] -> [Header]) -> RedditT m a -> RedditT m a
+withHeaders u f = RedditT $ liftF $ WithHeaders u f id
+
 failWith :: Monad m => APIError RedditError -> RedditT m a
 failWith = RedditT . liftF . FailWith
 
@@ -87,7 +97,7 @@
   parseJSON _ = mempty
 
 data LoginDetails = LoginDetails Modhash CookieJar
-  deriving (Show, Eq)
+  deriving (Show)
 
 instance Receivable LoginDetails where
   receive x = do
@@ -120,6 +130,12 @@
         rlResetTime' = fmap (\s -> addUTCTime (fromIntegral s) now) rlResetTime
         extract s = lookup s hs >>= readMaybe . BS.unpack
         trimap f (a, b, c) = (f a, f b, f c)
+
+data ClientParams = ClientParams Text Text
+  deriving (Show, Read, Eq, Ord)
+
+mkClientParamsHeader :: ClientParams -> (HeaderName, BS.ByteString)
+mkClientParamsHeader (ClientParams i s) = ("Authorization", Text.encodeUtf8 $ i <> ":" <> s)
 
 addAPIType :: Route -> Route
 addAPIType (Route fs ps m) = Route fs ("api_type" =. ("json" :: Text) : ps) m
diff --git a/test-anon/Reddit/Actions/CommentSpec.hs b/test-anon/Reddit/Actions/CommentSpec.hs
--- a/test-anon/Reddit/Actions/CommentSpec.hs
+++ b/test-anon/Reddit/Actions/CommentSpec.hs
@@ -29,11 +29,11 @@
       Left _ -> expectationFailure "something failed"
 
   it "should fail if we try to get an invalid comment" $ do
-    res <- runAnon $ getCommentInfo (CommentID "garbage")
+    res <- runAnon $ getCommentInfo (CommentID "!!!!!!!")
     res `shouldSatisfy` isLeft
 
   it "shouldn't be able to get a list of comment IDs where some are invalid" $ do
-    res <- runAnon $ getCommentsInfo [CommentID "c60o0iw", CommentID "garbage"]
+    res <- runAnon $ getCommentsInfo [CommentID "c60o0iw", CommentID "!!!!!!!"]
     res `shouldSatisfy` isLeft
 
   it "should be able to get mass comment IDs" $ do
diff --git a/test-io/ConfigLoad.hs b/test-io/ConfigLoad.hs
--- a/test-io/ConfigLoad.hs
+++ b/test-io/ConfigLoad.hs
@@ -1,49 +1,124 @@
 module ConfigLoad where
 
+import Control.Applicative
+import Data.List
+import Data.Semigroup (Semigroup(..))
 import Data.Text (Text)
 import Data.Yaml
 import Network.HTTP.Client
 import Network.HTTP.Client.TLS
 import Reddit
 import Reddit.Login
+import System.Directory
+import System.Environment
 import System.Exit
 import Utils
+import qualified Data.Text as Text
 
 newtype RunReddit = RunReddit
   { run :: forall a. Reddit a -> IO (Either (APIError RedditError) a) }
 
-newtype TestConfig = TestConfig (Maybe Config)
+data Opts =
+  Opts { optsUsername :: Maybe Text
+       , optsPassword :: Maybe Text
+       , optsSubreddit :: Maybe Text
+       , optsClientId :: Maybe Text
+       , optsClientSecret :: Maybe Text
+       }
   deriving (Show, Eq, Ord)
 
-instance FromJSON TestConfig where
-  parseJSON = withObject "TestConfig" $ \ o ->
-    TestConfig <$> o .:? "config"
+instance Semigroup Opts where
+  Opts u1 p1 s1 ci1 cs1 <> Opts u2 p2 s2 ci2 cs2 =
+    Opts (u2 <|> u1)
+         (p2 <|> p1)
+         (s2 <|> s1)
+         (ci2 <|> ci1)
+         (cs2 <|> cs1)
 
+instance Monoid Opts where
+  mappend = (<>)
+  mempty = Opts mempty mempty mempty mempty mempty
+
+instance FromJSON Opts where
+  parseJSON = withObject "Opts" $ \ o ->
+    Opts <$> o .:? "username"
+         <*> o .:? "password"
+         <*> o .:? "subreddit"
+         <*> o .:? "client_id"
+         <*> o .:? "client_secret"
+
+getEnvOpts :: IO Opts
+getEnvOpts =
+  Opts <$> lookupEnv' "REDDIT_USERNAME"
+       <*> lookupEnv' "REDDIT_PASSWORD"
+       <*> lookupEnv' "REDDIT_SUBREDDIT"
+       <*> lookupEnv' "REDDIT_CLIENT_ID"
+       <*> lookupEnv' "REDDIT_CLIENT_SECRET"
+    where
+      lookupEnv' x = fmap (fmap Text.pack) (lookupEnv x)
+
 data Config =
-  Config { tcUsername :: Text
-         , tcPassword :: Text
-         , tcSubreddit :: Text
+  Config { cfgUsername :: Text
+         , cfgPassword :: Text
+         , cfgSubreddit :: Text
+         , cfgClientId :: Text
+         , cfgClientSecret :: Text
          }
   deriving (Show, Eq, Ord)
 
-instance FromJSON Config where
-  parseJSON = withObject "Config" $ \ o ->
-    Config <$> o .: "username"
-           <*> o .: "password"
-           <*> o .: "subreddit"
+newtype Validation e a = Validation (Either e a)
+  deriving (Show, Read, Eq, Ord, Functor)
 
+instance Semigroup e => Applicative (Validation e) where
+  pure = Validation . Right
+
+  Validation a <*> Validation b =
+    Validation $ case (a, b) of
+      (Left ea, Left eb) -> Left (ea <> eb)
+      (Left ea, Right _) -> Left ea
+      (Right _, Left eb) -> Left eb
+      (Right f, Right x) -> Right (f x)
+
+optionsToConfig :: Opts -> Validation [String] Config
+optionsToConfig Opts{..} =
+  Config <$> get "optsUsername was missing" optsUsername
+         <*> get "optsPassword was missing" optsPassword
+         <*> get "optsSubreddit was missing" optsSubreddit
+         <*> get "optsClientId was missing" optsClientId
+         <*> get "optsClientSecret was missing" optsClientSecret
+    where
+      get :: String -> Maybe a -> Validation [String] a
+      get _ (Just x) = pure x
+      get msg Nothing = Validation (Left [msg])
+
 loadConfig :: IO (RunReddit, Username, SubredditName)
 loadConfig = do
-  decodeFileEither "test_config.yaml" >>= \case
-    Left err -> do
-      print err
-      exitFailure
-    Right (TestConfig Nothing) ->
-      putStrLn "Warning: missing config section, skipping authorized tests"
-      exitSuccess
-    Right (TestConfig (Just (Config user pass sub))) -> do
+  jsonOpts <- do
+    let configFilePath = "test_config.yaml"
+    doesFileExist configFilePath >>= \case
+      False -> do
+        putStrLn "Warning: missing config, skipping authorized tests"
+        pure mempty
+      True ->
+        decodeFileEither "test_config.yaml" >>= \case
+          Left err -> do
+            print err
+            exitFailure
+          Right opts -> pure opts
+  envOpts <- getEnvOpts
+
+  case optionsToConfig (jsonOpts <> envOpts) of
+    Validation (Left errs) ->
+      error $
+        intercalate "\n" $
+          [ "Options were missing, got:"
+          , "  " <> show (jsonOpts <> envOpts)
+          , "Errors:"
+          , intercalate "\n" $ map ("  " <>) errs
+          ]
+    Validation (Right (Config user pass sub ci cs)) -> do
       manager <- newManager tlsManagerSettings
-      res <- runAnon $ login user pass
+      res <- runAnon $ login user pass (ClientParams ci cs)
       case res of
         Left err -> do
           print err
diff --git a/test-io/Reddit/Actions/CommentSpec.hs b/test-io/Reddit/Actions/CommentSpec.hs
--- a/test-io/Reddit/Actions/CommentSpec.hs
+++ b/test-io/Reddit/Actions/CommentSpec.hs
@@ -32,11 +32,11 @@
       Left _ -> expectationFailure "something failed"
 
   it "should fail if we try to get an invalid comment" $ do
-    res <- run reddit $ getCommentInfo (CommentID "garbage")
+    res <- run reddit $ getCommentInfo (CommentID "!!!!!!!")
     res `shouldSatisfy` isLeft
 
   it "shouldn't be able to get a list of comment IDs where some are invalid" $ do
-    res <- run reddit $ getCommentsInfo [CommentID "c60o0iw", CommentID "garbage"]
+    res <- run reddit $ getCommentsInfo [CommentID "c60o0iw", CommentID "!!!!!!!"]
     res `shouldSatisfy` isLeft
 
   it "should be able to get mass comment IDs" $ do