diff --git a/hoauth.cabal b/hoauth.cabal
--- a/hoauth.cabal
+++ b/hoauth.cabal
@@ -1,5 +1,5 @@
 name: hoauth
-version: 0.3.2
+version: 0.3.2.1
 category: Network,Protocol,OAuth
 license: BSD3
 license-file: LICENSE
@@ -33,6 +33,7 @@
                  , Network.OAuth.Http.Response
                  , Network.OAuth.Http.HttpClient
                  , Network.OAuth.Http.CurlHttpClient
+                 , Network.OAuth.Http.DebugHttpClient
                  , Network.OAuth.Http.PercentEncoding
                  , Network.OAuth.Http.Util
                  , Network.OAuth.Consumer
diff --git a/src/main/haskell/Network/OAuth/Http/DebugHttpClient.hs b/src/main/haskell/Network/OAuth/Http/DebugHttpClient.hs
new file mode 100644
--- /dev/null
+++ b/src/main/haskell/Network/OAuth/Http/DebugHttpClient.hs
@@ -0,0 +1,59 @@
+-- Copyright (c) 2009, Diego Souza
+-- 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 the <ORGANIZATION> nor the names of its 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 HOLDER 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.
+
+-- | Minimum definition of a user agent required to implement oauth
+-- service calls. This should suffice for most applications.
+module Network.OAuth.Http.DebugHttpClient
+       ( DebugClient(..)
+       , stdDebugClient
+       ) where
+
+import Network.OAuth.Http.HttpClient
+import Network.OAuth.Http.Request
+import Network.OAuth.Http.Response
+import Control.Monad.Trans
+
+-- | A client that is able to debug interaction with HTTP servers.
+data DebugClient c = DebugClient { backend  :: c
+                                 , traceRq  :: Request -> IO ()
+                                 , traceRp  :: Response -> IO ()
+                                 , traceErr :: String -> IO ()
+                                 }
+
+-- | Creates the a instance which prints messages using putStrLn.
+stdDebugClient :: (HttpClient c) => c -> DebugClient c
+stdDebugClient c = DebugClient { backend  = c
+                               , traceRq  = putStrLn . ("Request: " ++) . show
+                               , traceRp  = putStrLn . ("Response: " ++) . show
+                               , traceErr = putStrLn . ("Error: "++) . show
+                               }
+
+instance (HttpClient c) => HttpClient (DebugClient c) where
+  runClient debug req = do { liftIO (traceRq debug $ req)
+                           ; rsp <- runClient (backend debug) req
+                           ; liftIO (either (traceErr debug) (traceRp debug) $ rsp)
+                           ; return rsp
+                           }