diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright Luke Hoersten (c) 2016
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Luke Hoersten nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/prometheus.cabal b/prometheus.cabal
new file mode 100644
--- /dev/null
+++ b/prometheus.cabal
@@ -0,0 +1,38 @@
+name:                prometheus
+version:             0.1.0.0
+synopsis:            Prometheus Haskell Client
+description:         Idiomatic Haskell client for Prometheus.io monitoring.
+homepage:            http://github.com/LukeHoersten/prometheus#readme
+license:             BSD3
+license-file:        LICENSE
+author:              Luke Hoersten
+maintainer:          luke@hoersten.org
+copyright:           All Rights Reserved
+category:            Web
+build-type:          Simple
+cabal-version:       >=1.10
+
+library
+  hs-source-dirs:      src
+  default-language:    Haskell2010
+
+  exposed-modules: System.Metrics.Prometheus.Counter
+                 , System.Metrics.Prometheus.Encode
+                 , System.Metrics.Prometheus.Gauge
+                 , System.Metrics.Prometheus.Histogram
+                 , System.Metrics.Prometheus.Metric
+                 , System.Metrics.Prometheus.MetricId
+                 , System.Metrics.Prometheus.Registry
+                 , System.Metrics.Prometheus.Sample
+                 , System.Metrics.Prometheus.Summary
+
+  build-depends: atomic-primops >= 0.8  && < 0.9
+               , base           >= 4.7  && < 5.0
+               , bytestring     >= 0.10 && < 0.11
+               , containers     >= 0.5  && < 0.6
+               , text           >= 1.2  && < 1.3
+
+
+source-repository head
+  type:     git
+  location: https://github.com/LukeHoersten/prometheus
diff --git a/src/System/Metrics/Prometheus/Counter.hs b/src/System/Metrics/Prometheus/Counter.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Counter.hs
@@ -0,0 +1,24 @@
+module System.Metrics.Prometheus.Counter where
+
+
+import           Data.Atomics.Counter (AtomicCounter, incrCounter_, newCounter,
+                                       readCounter)
+
+
+newtype Counter = Counter { unCounter :: AtomicCounter }
+
+
+new :: IO Counter
+new = Counter <$> newCounter 0
+
+
+add :: Int -> Counter -> IO ()
+add by = incrCounter_ by . unCounter
+
+
+inc :: Counter -> IO ()
+inc = add 1
+
+
+view :: Counter -> IO Int
+view = readCounter . unCounter
diff --git a/src/System/Metrics/Prometheus/Encode.hs b/src/System/Metrics/Prometheus/Encode.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Encode.hs
@@ -0,0 +1,113 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module System.Metrics.Prometheus.Encode
+       ( encodeMetrics
+       , serializeMetrics
+       ) where
+
+import           Data.ByteString.Builder            (Builder, byteString, char8,
+                                                     doubleDec, intDec,
+                                                     toLazyByteString)
+import           Data.ByteString.Lazy               (ByteString)
+import           Data.List                          (intersperse)
+import qualified Data.Map                           as Map
+import           Data.Monoid                        ((<>))
+import           Data.Text                          (Text, replace)
+import           Data.Text.Encoding                 (encodeUtf8)
+
+import           System.Metrics.Prometheus.MetricId (MetricId (..))
+import           System.Metrics.Prometheus.Sample   (CounterSample (..),
+                                                     GaugeSample (..),
+                                                     MetricSample (..),
+                                                     RegistrySample (..),
+                                                     metricSample)
+
+
+serializeMetrics :: RegistrySample -> ByteString
+serializeMetrics = toLazyByteString . encodeMetrics
+
+
+encodeMetrics :: RegistrySample -> Builder
+encodeMetrics = mconcat . intersperse "\n\n" .
+    map (uncurry encodeMetric) . Map.toList . unRegistrySample
+
+
+encodeMetric :: MetricId -> MetricSample -> Builder
+encodeMetric mid sample
+    =  encodeHeader mid sample <> newline
+    <> metricSample (encodeCounter mid) (encodeGauge mid) encodeHistogram encodeSummary sample
+
+
+encodeHeader :: MetricId -> MetricSample -> Builder
+encodeHeader mid sample
+    =  "# HELP " <> encodeName mid <> space <> "help" <> newline
+    <> "# TYPE " <> encodeName mid <> space <> encodeSampleType sample
+
+
+-- escape :: Text -> Text
+-- escape = replace "\\" "\\\" . replace "\"" ("\\" <> "\"")
+
+
+encodeHistogram = undefined
+encodeSummary = undefined
+
+
+encodeCounter :: MetricId -> CounterSample -> Builder
+encodeCounter mid counter = encodeMetricId mid <> space <> intDec (unCounterSample counter)
+
+
+encodeGauge :: MetricId -> GaugeSample -> Builder
+encodeGauge mid gauge = encodeMetricId mid <> space <> doubleDec (unGaugeSample gauge)
+
+
+encodeSampleType :: MetricSample -> Builder
+encodeSampleType = byteString . metricSample (const "counter")
+    (const "gauge") (const "histogram") (const "summary")
+
+
+encodeMetricId :: MetricId -> Builder
+encodeMetricId mid = encodeName mid <> encodeLabels mid
+
+
+encodeName :: MetricId -> Builder
+encodeName = text . name
+
+
+encodeLabels :: MetricId -> Builder
+encodeLabels mid | Map.null (labels mid) = space
+                 | otherwise =
+                   openBracket
+                   <> (mconcat . intersperse comma . map encodeLabel . Map.toList $ labels mid)
+                   <> closeBracket
+
+
+encodeLabel :: (Text, Text) -> Builder
+encodeLabel (key, value) = text key <> equals <> text value
+
+
+text :: Text -> Builder
+text = byteString . encodeUtf8
+
+
+space :: Builder
+space = char8 ' '
+
+
+newline :: Builder
+newline = char8 '\n'
+
+
+openBracket :: Builder
+openBracket = char8 '{'
+
+
+closeBracket :: Builder
+closeBracket = char8 '}'
+
+
+comma :: Builder
+comma = char8 ','
+
+
+equals :: Builder
+equals = char8 '='
diff --git a/src/System/Metrics/Prometheus/Gauge.hs b/src/System/Metrics/Prometheus/Gauge.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Gauge.hs
@@ -0,0 +1,35 @@
+module System.Metrics.Prometheus.Gauge where
+
+import           Data.IORef (IORef, atomicModifyIORef', atomicWriteIORef,
+                             newIORef, readIORef)
+
+
+newtype Gauge = Gauge { unGauge :: IORef Double }
+
+
+new :: IO Gauge
+new = Gauge <$> newIORef 0
+
+add :: Double -> Gauge -> IO ()
+add x = flip atomicModifyIORef' f . unGauge
+  where f v = (v + x, ())
+
+
+sub :: Double -> Gauge -> IO ()
+sub x = flip atomicModifyIORef' f . unGauge
+  where f v = (v - x, ())
+
+inc :: Gauge -> IO ()
+inc = add 1
+
+
+dec :: Gauge -> IO ()
+dec = sub 1
+
+
+set :: Double -> Gauge -> IO ()
+set x = flip atomicWriteIORef x . unGauge
+
+
+get :: Gauge -> IO Double
+get = readIORef . unGauge
diff --git a/src/System/Metrics/Prometheus/Histogram.hs b/src/System/Metrics/Prometheus/Histogram.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Histogram.hs
@@ -0,0 +1,1 @@
+module System.Metrics.Prometheus.Histogram where
diff --git a/src/System/Metrics/Prometheus/Metric.hs b/src/System/Metrics/Prometheus/Metric.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Metric.hs
@@ -0,0 +1,12 @@
+module System.Metrics.Prometheus.Metric where
+
+import qualified System.Metrics.Prometheus.Counter as C
+import qualified System.Metrics.Prometheus.Gauge   as G
+-- import qualified System.Metrics.Prometheus.Histogram as H
+-- import qualified System.Metrics.Prometheus.Summary   as S
+
+data Metric
+    = Counter C.Counter
+    | Gauge G.Gauge
+    -- | Summary S.Summary
+    -- | Histogram H.Histogram
diff --git a/src/System/Metrics/Prometheus/MetricId.hs b/src/System/Metrics/Prometheus/MetricId.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/MetricId.hs
@@ -0,0 +1,11 @@
+module System.Metrics.Prometheus.MetricId where
+
+import           Data.Map  (Map)
+import           Data.Text (Text)
+
+
+data MetricId =
+    MetricId
+    { name   :: Text
+    , labels :: Map Text Text
+    } deriving (Eq, Ord)
diff --git a/src/System/Metrics/Prometheus/Registry.hs b/src/System/Metrics/Prometheus/Registry.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Registry.hs
@@ -0,0 +1,29 @@
+module System.Metrics.Prometheus.Registry where
+
+import           Data.Map                           (Map)
+import qualified Data.Map                           as Map
+
+import           System.Metrics.Prometheus.Counter  (Counter)
+import qualified System.Metrics.Prometheus.Counter  as Counter
+import           System.Metrics.Prometheus.Gauge    (Gauge)
+import qualified System.Metrics.Prometheus.Gauge    as Gauge
+import           System.Metrics.Prometheus.Metric   (Metric)
+import qualified System.Metrics.Prometheus.Metric   as Metric
+import           System.Metrics.Prometheus.MetricId (MetricId)
+
+
+newtype Registry = Registry { unRegistry :: Map MetricId Metric }
+
+
+registerCounter :: MetricId -> Registry -> IO (Counter, Registry)
+registerCounter mid registry = do
+    counter <- Counter.new
+    return (counter, Registry $ Map.insertWithKey collision mid (Metric.Counter counter) (unRegistry registry))
+  where collision k n o = error "oh shit"
+
+
+registerGauge :: MetricId -> Registry -> IO (Gauge, Registry)
+registerGauge mid registry = do
+    gauge <- Gauge.new
+    return (gauge, Registry $ Map.insertWithKey collision mid (Metric.Gauge gauge) (unRegistry registry))
+  where collision k n o = error "oh shit"
diff --git a/src/System/Metrics/Prometheus/Sample.hs b/src/System/Metrics/Prometheus/Sample.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Sample.hs
@@ -0,0 +1,60 @@
+module System.Metrics.Prometheus.Sample where
+
+
+import           Data.Map                           (Map)
+
+import qualified System.Metrics.Prometheus.Counter  as Counter
+import qualified System.Metrics.Prometheus.Gauge    as Gauge
+import           System.Metrics.Prometheus.Metric   (Metric)
+import qualified System.Metrics.Prometheus.Metric   as Metric
+import           System.Metrics.Prometheus.MetricId (MetricId)
+import           System.Metrics.Prometheus.Registry (Registry, unRegistry)
+
+
+newtype CounterSample = CounterSample { unCounterSample :: Int }
+
+newtype GaugeSample = GaugeSample { unGaugeSample :: Double }
+
+
+data HistogramSample =
+    HistogramSample
+    { histBuckets :: Map Double Int
+    , histSum     :: Int
+    , histCount   :: Int
+    }
+
+
+data SummarySample =
+    SummarySample
+    { sumQuantiles :: Map Double Int
+    , sumSum       :: Int
+    , sumCount     :: Int
+    }
+
+
+data MetricSample
+    = Counter CounterSample
+    | Gauge GaugeSample
+    | Histogram HistogramSample
+    | Summary SummarySample
+
+
+metricSample :: (CounterSample -> a) -> (GaugeSample -> a)
+             -> (HistogramSample -> a) -> (SummarySample -> a)
+             -> MetricSample -> a
+metricSample f _ _ _ (Counter s)   = f s
+metricSample _ f _ _ (Gauge s)     = f s
+metricSample _ _ f _ (Histogram s) = f s
+metricSample _ _ _ f (Summary s)   = f s
+
+
+newtype RegistrySample = RegistrySample { unRegistrySample :: Map MetricId MetricSample }
+
+
+sample :: Registry -> IO RegistrySample
+sample = fmap RegistrySample . mapM sampleMetric . unRegistry
+
+
+sampleMetric :: Metric -> IO MetricSample
+sampleMetric (Metric.Counter count) = Counter . CounterSample <$> Counter.view count
+sampleMetric (Metric.Gauge gauge) = Gauge . GaugeSample <$> Gauge.get gauge
diff --git a/src/System/Metrics/Prometheus/Summary.hs b/src/System/Metrics/Prometheus/Summary.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Metrics/Prometheus/Summary.hs
@@ -0,0 +1,1 @@
+module System.Metrics.Prometheus.Summary where