diff --git a/Example.hs b/Example.hs
--- a/Example.hs
+++ b/Example.hs
@@ -2,24 +2,22 @@
 
 module Example where
 
-import           System.Metrics.Prometheus.GlobalRegistry
-import           System.Metrics.Prometheus.Http
-import           System.Metrics.Prometheus.Metric.Counter (inc)
+import           Control.Monad.IO.Class                         (liftIO)
+import           System.Metrics.Prometheus.Concurrent.Http      (serveHttpTextMetricsT)
+import           System.Metrics.Prometheus.Concurrent.RegistryT
+import           System.Metrics.Prometheus.Metric.Counter       (inc)
 import           System.Metrics.Prometheus.MetricId
 
-
 main :: IO ()
-main = do
-    globalRegistry <- new
-
+main = runRegistryT $ do
     -- Labels can be defined as lists or added to an empty label set
-    connectSuccessGauge <- registerGauge "example_connections" (fromList [("login", "success")]) globalRegistry
-    connectFailureGauge <- registerGauge "example_connections" (addLabel "login" "failure" mempty) globalRegistry
-    connectCounter <- registerCounter "example_connection_total" mempty globalRegistry
-    latencyHistogram <- registerHistogram "example_round_trip_latency_ms" mempty [10, 20..100] globalRegistry
+    connectSuccessGauge <- registerGauge "example_connections" (fromList [("login", "success")])
+    connectFailureGauge <- registerGauge "example_connections" (addLabel "login" "failure" mempty)
+    connectCounter <- registerCounter "example_connection_total" mempty
+    latencyHistogram <- registerHistogram "example_round_trip_latency_ms" mempty [10, 20..100]
 
-    inc connectCounter -- increment a counter
+    liftIO $ inc connectCounter -- increment a counter
 
     -- [...] pass metric handles to the rest of the app
 
-    serveHttpTextMetrics 8080 globalRegistry -- http://localhost:8080/metric server
+    serveHttpTextMetricsT 8080 ["metrics"] -- http://localhost:8080/metric server
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -15,27 +15,25 @@
 
 module Example where
 
-import           System.Metrics.Prometheus.GlobalRegistry
-import           System.Metrics.Prometheus.Http
-import           System.Metrics.Prometheus.Metric.Counter (inc)
+import           Control.Monad.IO.Class                         (liftIO)
+import           System.Metrics.Prometheus.Concurrent.Http      (serveHttpTextMetricsT)
+import           System.Metrics.Prometheus.Concurrent.RegistryT
+import           System.Metrics.Prometheus.Metric.Counter       (inc)
 import           System.Metrics.Prometheus.MetricId
 
-
 main :: IO ()
-main = do
-    globalRegistry <- new
-
+main = runRegistryT $ do
     -- Labels can be defined as lists or added to an empty label set
-    connectSuccessGauge <- registerGauge "example_connections" (fromList [("login", "success")]) globalRegistry
-    connectFailureGauge <- registerGauge "example_connections" (addLabel "login" "failure" mempty) globalRegistry
-    connectCounter <- registerCounter "example_connection_total" mempty globalRegistry
-    latencyHistogram <- registerHistogram "example_round_trip_latency_ms" mempty [10, 20..100] globalRegistry
+    connectSuccessGauge <- registerGauge "example_connections" (fromList [("login", "success")])
+    connectFailureGauge <- registerGauge "example_connections" (addLabel "login" "failure" mempty)
+    connectCounter <- registerCounter "example_connection_total" mempty
+    latencyHistogram <- registerHistogram "example_round_trip_latency_ms" mempty [10, 20..100]
 
-    inc connectCounter -- increment a counter
+    liftIO $ inc connectCounter -- increment a counter
 
     -- [...] pass metric handles to the rest of the app
 
-    serveHttpTextMetrics 8080 globalRegistry -- http://localhost:8080/metric server
+    serveHttpTextMetricsT 8080 ["metrics"] -- http://localhost:8080/metric server
 ```
 
 ## Advanced Usage
diff --git a/prometheus.cabal b/prometheus.cabal
--- a/prometheus.cabal
+++ b/prometheus.cabal
@@ -1,5 +1,5 @@
 name:                prometheus
-version:             0.2.0
+version:             0.3.0
 synopsis:            Prometheus Haskell Client
 homepage:            http://github.com/LukeHoersten/prometheus#readme
 bug-reports:         http://github.com/LukeHoersten/prometheus/issues
@@ -24,27 +24,25 @@
   .
   > module Example where
   >
-  > import           System.Metrics.Prometheus.GlobalRegistry
-  > import           System.Metrics.Prometheus.Http
-  > import           System.Metrics.Prometheus.Metric.Counter (inc)
+  > import           Control.Monad.IO.Class                         (liftIO)
+  > import           System.Metrics.Prometheus.Concurrent.Http      (serveHttpTextMetricsT)
+  > import           System.Metrics.Prometheus.Concurrent.RegistryT
+  > import           System.Metrics.Prometheus.Metric.Counter       (inc)
   > import           System.Metrics.Prometheus.MetricId
   >
-  >
   > main :: IO ()
-  > main = do
-  >     globalRegistry <- new
-  >
+  > main = runRegistryT $ do
   >     -- Labels can be defined as lists or added to an empty label set
-  >     connectSuccessGauge <- registerGauge "example_connections" (fromList [("login", "success")]) globalRegistry
-  >     connectFailureGauge <- registerGauge "example_connections" (addLabel "login" "failure" mempty) globalRegistry
-  >     connectCounter <- registerCounter "example_connection_total" mempty globalRegistry
-  >     latencyHistogram <- registerHistogram "example_round_trip_latency_ms" mempty [10, 20..100] globalRegistry
+  >     connectSuccessGauge <- registerGauge "example_connections" (fromList [("login", "success")])
+  >     connectFailureGauge <- registerGauge "example_connections" (addLabel "login" "failure" mempty)
+  >     connectCounter <- registerCounter "example_connection_total" mempty
+  >     latencyHistogram <- registerHistogram "example_round_trip_latency_ms" mempty [10, 20..100]
   >
-  >     inc connectCounter -- increment a counter
+  >     liftIO $ inc connectCounter -- increment a counter
   >
   >     -- [...] pass metric handles to the rest of the app
   >
-  >     serveHttpTextMetrics 8080 globalRegistry -- http://localhost:8080/metric server
+  >     serveHttpTextMetricsT 8080 ["metrics"] -- http://localhost:8080/metric server
   >
   .
   [Advanced Usage]
@@ -60,11 +58,12 @@
   hs-source-dirs:      src
   default-language:    Haskell2010
 
-  exposed-modules: System.Metrics.Prometheus.Encode
+  exposed-modules: System.Metrics.Prometheus.Concurrent.Http
+                 , System.Metrics.Prometheus.Concurrent.Registry
+                 , System.Metrics.Prometheus.Concurrent.RegistryT
+                 , System.Metrics.Prometheus.Encode
                  , System.Metrics.Prometheus.Encode.Histogram
                  , System.Metrics.Prometheus.Encode.MetricId
-                 , System.Metrics.Prometheus.GlobalRegistry
-                 , System.Metrics.Prometheus.Http
                  , System.Metrics.Prometheus.Metric
                  , System.Metrics.Prometheus.Metric.Counter
                  , System.Metrics.Prometheus.Metric.Gauge
diff --git a/src/System/Metrics/Prometheus/Concurrent/Http.hs b/src/System/Metrics/Prometheus/Concurrent/Http.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Concurrent/Http.hs
@@ -0,0 +1,55 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module System.Metrics.Prometheus.Concurrent.Http where
+
+import           Control.Monad.IO.Class                         (liftIO)
+import           Control.Monad.Reader.Class                     (ask)
+import           Data.Text                                      (Text)
+import           Network.HTTP.Types                             (hContentType,
+                                                                 methodGet,
+                                                                 status200,
+                                                                 status404)
+import           Network.Wai                                    (Application,
+                                                                 Response,
+                                                                 pathInfo,
+                                                                 requestMethod,
+                                                                 responseBuilder,
+                                                                 responseLBS)
+import           Network.Wai.Handler.Warp                       (Port, run)
+
+import           System.Metrics.Prometheus.Concurrent.Registry  (Registry,
+                                                                 sample)
+import           System.Metrics.Prometheus.Concurrent.RegistryT (RegistryT)
+import           System.Metrics.Prometheus.Encode               (encodeMetrics)
+
+
+type Path = [Text]
+
+
+serveHttpTextMetricsDef :: Port -> Registry -> IO ()
+serveHttpTextMetricsDef = flip serveHttpTextMetrics ["metrics"]
+
+
+serveHttpTextMetrics :: Port -> Path -> Registry -> IO ()
+serveHttpTextMetrics port path = run port . prometheusApp path
+
+
+serveHttpTextMetricsT :: Port -> Path -> RegistryT IO ()
+serveHttpTextMetricsT port path = liftIO . serveHttpTextMetrics port path =<< ask
+
+
+prometheusApp :: Path -> Registry -> Application
+prometheusApp path registry request respond
+    | prometheusRequest = prometheusResponse respond registry
+    | otherwise = respond $ responseLBS status404 header404 body404
+  where
+    prometheusRequest = requestMethod request == methodGet && pathInfo request == path
+    header404 = [(hContentType, "text/plain")]
+    body404 = "404"
+
+
+prometheusResponse :: (Response -> IO b) -> Registry -> IO b
+prometheusResponse respond gr =
+    respond . responseBuilder status200 headers . encodeMetrics =<< sample gr
+  where
+    headers = [(hContentType, "text/plain; version=0.0.4")]
diff --git a/src/System/Metrics/Prometheus/Concurrent/Registry.hs b/src/System/Metrics/Prometheus/Concurrent/Registry.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Concurrent/Registry.hs
@@ -0,0 +1,50 @@
+module System.Metrics.Prometheus.Concurrent.Registry
+       ( Registry
+       , new
+       , registerCounter
+       , registerGauge
+       , registerHistogram
+       , sample
+       ) where
+
+
+import           Control.Concurrent.MVar                    (MVar,
+                                                             modifyMVarMasked,
+                                                             newMVar, withMVar)
+import           Data.Tuple                                 (swap)
+
+import           System.Metrics.Prometheus.Metric.Counter   (Counter)
+import           System.Metrics.Prometheus.Metric.Gauge     (Gauge)
+import           System.Metrics.Prometheus.Metric.Histogram (Histogram,
+                                                             UpperBound)
+import           System.Metrics.Prometheus.MetricId         (Labels, Name)
+import qualified System.Metrics.Prometheus.Registry         as R
+
+
+newtype Registry = Registry { unRegistry :: MVar R.Registry }
+
+
+new :: IO Registry
+new = Registry <$> newMVar R.new
+
+
+registerCounter :: Name -> Labels -> Registry -> IO Counter
+registerCounter name labels = flip modifyMVarMasked register . unRegistry
+  where
+    register = fmap swap . R.registerCounter name labels
+
+
+registerGauge :: Name -> Labels -> Registry -> IO Gauge
+registerGauge name labels = flip modifyMVarMasked register . unRegistry
+  where
+    register = fmap swap . R.registerGauge name labels
+
+
+registerHistogram :: Name -> Labels -> [UpperBound] -> Registry -> IO Histogram
+registerHistogram name labels buckets = flip modifyMVarMasked register . unRegistry
+  where
+    register = fmap swap . R.registerHistogram name labels buckets
+
+
+sample :: Registry -> IO R.RegistrySample
+sample = flip withMVar R.sample . unRegistry
diff --git a/src/System/Metrics/Prometheus/Concurrent/RegistryT.hs b/src/System/Metrics/Prometheus/Concurrent/RegistryT.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Concurrent/RegistryT.hs
@@ -0,0 +1,44 @@
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+
+module System.Metrics.Prometheus.Concurrent.RegistryT where
+
+import           Control.Monad.IO.Class                        (MonadIO, liftIO)
+import           Control.Monad.Reader.Class                    (MonadReader,
+                                                                ask)
+import           Control.Monad.Trans.Class                     (MonadTrans)
+import           Control.Monad.Trans.Reader                    (ReaderT (..))
+
+import           System.Metrics.Prometheus.Concurrent.Registry (Registry, new)
+import qualified System.Metrics.Prometheus.Concurrent.Registry as R
+import           System.Metrics.Prometheus.Metric.Counter      (Counter)
+import           System.Metrics.Prometheus.Metric.Gauge        (Gauge)
+import           System.Metrics.Prometheus.Metric.Histogram    (Histogram)
+import qualified System.Metrics.Prometheus.Metric.Histogram    as Histogram
+import           System.Metrics.Prometheus.MetricId            (Labels, Name)
+import           System.Metrics.Prometheus.Registry            (RegistrySample)
+
+
+newtype RegistryT m a =
+    RegistryT { unRegistryT :: ReaderT Registry m a }
+    deriving ( Monad, MonadTrans, Applicative, Functor
+             , MonadReader Registry, MonadIO)
+
+
+runRegistryT :: MonadIO m => RegistryT m a -> m a
+runRegistryT registry = liftIO new >>= runReaderT (unRegistryT registry)
+
+
+registerCounter :: MonadIO m => Name -> Labels -> RegistryT m Counter
+registerCounter n l = ask >>= liftIO . R.registerCounter n l
+
+
+registerGauge :: MonadIO m => Name -> Labels -> RegistryT m Gauge
+registerGauge n l = ask >>= liftIO . R.registerGauge n l
+
+
+registerHistogram :: MonadIO m => Name -> Labels -> [Histogram.UpperBound] -> RegistryT m Histogram
+registerHistogram n l b = ask >>= liftIO . R.registerHistogram n l b
+
+
+sample :: MonadIO m => RegistryT m RegistrySample
+sample = ask >>= liftIO . R.sample
diff --git a/src/System/Metrics/Prometheus/GlobalRegistry.hs b/src/System/Metrics/Prometheus/GlobalRegistry.hs
deleted file mode 100644
--- a/src/System/Metrics/Prometheus/GlobalRegistry.hs
+++ /dev/null
@@ -1,52 +0,0 @@
-module System.Metrics.Prometheus.GlobalRegistry
-       ( GlobalRegistry
-       , new
-       , registerCounter
-       , registerGauge
-       , registerHistogram
-       , sample
-       ) where
-
-
-import           Control.Concurrent.MVar                    (MVar,
-                                                             modifyMVarMasked,
-                                                             newMVar, withMVar)
-import           Data.Tuple                                 (swap)
-
-import           System.Metrics.Prometheus.Metric.Counter   (Counter)
-import           System.Metrics.Prometheus.Metric.Gauge     (Gauge)
-import           System.Metrics.Prometheus.Metric.Histogram (Histogram,
-                                                             UpperBound)
-import           System.Metrics.Prometheus.MetricId         (Labels, Name)
-import           System.Metrics.Prometheus.Registry         (Registry (..),
-                                                             RegistrySample)
-import qualified System.Metrics.Prometheus.Registry         as R
-
-
-newtype GlobalRegistry = GlobalRegistry { unGlobalRegistry :: MVar Registry }
-
-
-new :: IO GlobalRegistry
-new = GlobalRegistry <$> newMVar R.new
-
-
-registerCounter :: Name -> Labels -> GlobalRegistry -> IO Counter
-registerCounter name labels = flip modifyMVarMasked register . unGlobalRegistry
-  where
-    register = fmap swap . R.registerCounter name labels
-
-
-registerGauge :: Name -> Labels -> GlobalRegistry -> IO Gauge
-registerGauge name labels = flip modifyMVarMasked register . unGlobalRegistry
-  where
-    register = fmap swap . R.registerGauge name labels
-
-
-registerHistogram :: Name -> Labels -> [UpperBound] -> GlobalRegistry -> IO Histogram
-registerHistogram name labels buckets = flip modifyMVarMasked register . unGlobalRegistry
-  where
-    register = fmap swap . R.registerHistogram name labels buckets
-
-
-sample :: GlobalRegistry -> IO RegistrySample
-sample = flip withMVar R.sample . unGlobalRegistry
diff --git a/src/System/Metrics/Prometheus/Http.hs b/src/System/Metrics/Prometheus/Http.hs
deleted file mode 100644
--- a/src/System/Metrics/Prometheus/Http.hs
+++ /dev/null
@@ -1,46 +0,0 @@
-{-# LANGUAGE OverloadedStrings #-}
-
-module System.Metrics.Prometheus.Http where
-
-import           Data.Text                                (Text)
-import           Network.HTTP.Types                       (hContentType,
-                                                           methodGet, status200,
-                                                           status404)
-import           Network.Wai                              (Application,
-                                                           Response, pathInfo,
-                                                           requestMethod,
-                                                           responseBuilder,
-                                                           responseLBS)
-import           Network.Wai.Handler.Warp                 (Port, run)
-
-import           System.Metrics.Prometheus.Encode         (encodeMetrics)
-import           System.Metrics.Prometheus.GlobalRegistry (GlobalRegistry,
-                                                           sample)
-
-
-type Path = [Text]
-
-
-serveHttpTextMetricsDef :: Port -> GlobalRegistry -> IO ()
-serveHttpTextMetricsDef = serveHttpTextMetrics ["metrics"]
-
-
-serveHttpTextMetrics :: Path -> Port -> GlobalRegistry -> IO ()
-serveHttpTextMetrics path port = run port . prometheusApp path
-
-
-prometheusApp :: Path -> GlobalRegistry -> Application
-prometheusApp path globalRegistry request respond
-    | prometheusRequest = prometheusResponse respond globalRegistry
-    | otherwise = respond $ responseLBS status404 header404 body404
-  where
-    prometheusRequest = requestMethod request == methodGet && pathInfo request == path
-    header404 = [(hContentType, "text/plain")]
-    body404 = "404"
-
-
-prometheusResponse :: (Response -> IO b) -> GlobalRegistry -> IO b
-prometheusResponse respond gr =
-    respond . responseBuilder status200 headers . encodeMetrics =<< sample gr
-  where
-    headers = [(hContentType, "text/plain; version=0.0.4")]