diff --git a/apiary.cabal b/apiary.cabal
--- a/apiary.cabal
+++ b/apiary.cabal
@@ -1,5 +1,5 @@
 name:                apiary
-version:             0.8.0.0
+version:             0.9.0.0
 synopsis:            Simple web framework inspired by scotty.
 description:
   Simple web framework inspired by scotty.
@@ -50,8 +50,13 @@
 -- extra-source-files:  
 cabal-version:       >=1.10
 
+flag wai3
+  description: use wai-3.0
+  default: False
+
 library
   exposed-modules:     Web.Apiary
+                       Web.Apiary.Wai
 
                        Control.Monad.Apiary
                        Control.Monad.Apiary.Filter
@@ -77,7 +82,6 @@
                        
   build-depends:       base              >=4.6 && <4.8
                      , template-haskell  >=2.8 && <2.10
-                     , transformers      >=0.3 && <0.5
                      , mtl               >=2.1 && <2.3
                      , monad-control     >=0.3 && <0.4
                      , transformers-base >=0.4 && <0.5
@@ -85,16 +89,21 @@
                      , text               >=1.1 && <1.2
                      , bytestring         >=0.10 && <0.11
                      , blaze-builder      >=0.3 && <0.4
-                     , conduit            >=1.1 && <1.2
                      , data-default-class >=0.0 && <0.1
                      , tagged             >=0.7 && <0.8
                      , reflection         >=1.4 && <1.5
 
                      , http-types        >=0.8 && <0.9
                      , mime-types        >=0.1 && <0.2
-                     , wai               >=2.1 && <2.2
-                     , warp              >=2.1 && <2.2
                      , exceptions        >=0.6 && <0.7
+  if flag(wai3)
+    build-depends:     wai               >=3.0 && <3.1
+                     , wai-extra         >=3.0 && <3.1
+    cpp-options:       -DWAI3
+  else
+    build-depends:     wai               >=2.1 && <2.2
+                     , wai-extra         >=2.1 && <2.2
+                     , conduit           >=1.1 && <1.2
 
   hs-source-dirs:      src
   ghc-options:         -O2 -Wall
@@ -106,11 +115,16 @@
   build-depends:       base                 >=4.6 && <4.8
                      , test-framework       >=0.8 && <0.9
                      , test-framework-hunit >=0.3 && <0.4
-                     , wai                  >=2.1 && <2.2
-                     , wai-test             >=2.0 && <2.1
                      , apiary
                      , bytestring           >=0.10 && <0.11
-                     , http-types        >=0.8 && <0.9
+                     , http-types           >=0.8  && <0.9
+  if flag(wai3)
+    build-depends:     wai               >=3.0 && <3.1
+                     , wai-test          >=3.0 && <3.1
+  else
+    build-depends:     wai               >=2.1 && <2.2
+                     , wai-test          >=2.0 && <2.1
+
   hs-source-dirs:      test
   ghc-options:         -O2 -Wall -fno-warn-missing-signatures
   default-language:    Haskell2010
diff --git a/src/Control/Monad/Apiary/Action.hs b/src/Control/Monad/Apiary/Action.hs
--- a/src/Control/Monad/Apiary/Action.hs
+++ b/src/Control/Monad/Apiary/Action.hs
@@ -8,6 +8,8 @@
     -- ** getter
     , getRequest
     , getHeaders
+    , getReqParams
+    , getReqFiles
 
     -- ** setter
     , status
@@ -19,7 +21,8 @@
     , file'
     , builder
     , lbs
-    , source
+    , stream
+    , StreamingBody
 
     -- ** monolithic action
     -- *** redirect
@@ -29,7 +32,7 @@
     , module Data.Default.Class
     
     -- * deprecated
-    , redirectFound, redirectSeeOther
+    , redirectFound, redirectSeeOther, source
     ) where
 
 import Control.Monad.Apiary.Action.Internal
diff --git a/src/Control/Monad/Apiary/Action/Internal.hs b/src/Control/Monad/Apiary/Action/Internal.hs
--- a/src/Control/Monad/Apiary/Action/Internal.hs
+++ b/src/Control/Monad/Apiary/Action/Internal.hs
@@ -6,6 +6,7 @@
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE Rank2Types #-}
 {-# LANGUAGE NoMonomorphismRestriction #-}
+{-# LANGUAGE CPP #-}
 
 module Control.Monad.Apiary.Action.Internal where
 
@@ -17,6 +18,7 @@
 import Control.Monad.Catch
 import Control.Monad.Trans.Control
 import Network.Wai
+import Network.Wai.Parse
 import Network.Mime
 import Data.Default.Class
 import Network.HTTP.Types
@@ -24,7 +26,10 @@
 import qualified Data.ByteString as S
 import qualified Data.ByteString.Lazy as L
 import qualified Data.Text as T
+
+#ifndef WAI3
 import Data.Conduit
+#endif
 
 data ApiaryConfig = ApiaryConfig
     { -- | call when no handler matched.
@@ -38,10 +43,16 @@
     , mimeType      :: FilePath -> S.ByteString
     }
 
+defNotFound :: Application
+#ifdef WAI3
+defNotFound _ f = f $ responseLBS status404 [("Content-Type", "text/plain")] "404 Page Notfound.\n"
+#else
+defNotFound _ = return $ responseLBS status404 [("Content-Type", "text/plain")] "404 Page Notfound.\n"
+#endif
+
 instance Default ApiaryConfig where
     def = ApiaryConfig 
-        { notFound = \_ -> return $ responseLBS status404 
-            [("Content-Type", "text/plain")] "404 Page Notfound.\n"
+        { notFound      = defNotFound
         , defaultStatus = ok200
         , defaultHeader = []
         , rootPattern   = ["", "/", "/index.html", "/index.htm"]
@@ -53,20 +64,29 @@
         { actionStatus  :: Status
         , actionHeaders :: ResponseHeaders
         , actionBody    :: Body
+        , actionReqBody :: Maybe ([Param], [File L.ByteString])
         }
 
+#ifndef WAI3
+type StreamingBody = Source IO (Flush Builder)
+#endif
+
 data Body 
     = File FilePath (Maybe FilePart)
     | Builder Builder
     | LBS L.ByteString
-    | SRC (Source IO (Flush Builder))
+    | Str StreamingBody
 
 actionStateToResponse :: ActionState -> Response
 actionStateToResponse as = case actionBody as of
     File f p  -> responseFile st hd f p
     Builder b -> responseBuilder st hd b
     LBS l     -> responseLBS st hd l
-    SRC    s  -> responseSource st hd s
+#ifdef WAI3
+    Str    s  -> responseStream st hd s
+#else
+    Str    s  -> responseSource st hd s
+#endif
   where
     st = actionStatus  as
     hd = actionHeaders as
@@ -134,12 +154,22 @@
 hoistActionT run m = actionT $ \c r s -> run (runActionT m c r s)
 
 execActionT :: ApiaryConfig -> ActionT IO () -> Application
+
+#ifdef WAI3
+execActionT config m request send = runActionT m config request resp >>= \case
+        Pass           -> notFound config request send
+        Stop s         -> send s
+        Continue (_,r) -> send $ actionStateToResponse r
+  where
+    resp = ActionState (defaultStatus config) (defaultHeader config) (LBS "") Nothing
+#else
 execActionT config m request = runActionT m config request resp >>= \case
         Pass           -> notFound config request
         Stop s         -> return s
         Continue (_,r) -> return $ actionStateToResponse r
   where
-    resp = ActionState (defaultStatus config) (defaultHeader config) (LBS "")
+    resp = ActionState (defaultStatus config) (defaultHeader config) (LBS "") Nothing
+#endif
 
 instance (Monad m, Functor m) => Alternative (ActionT m) where
     empty = mzero
@@ -182,6 +212,21 @@
 getRequest :: Monad m => ActionT m Request
 getRequest = ActionT $ \_ r s c -> c r s
 
+getRequestBody :: MonadIO m => ActionT m ([Param], [File L.ByteString])
+getRequestBody = ActionT $ \_ r s c -> case actionReqBody s of
+    Just b  -> c b s
+    Nothing -> do
+        b <- liftIO $ parseRequestBody lbsBackEnd r
+        c b s { actionReqBody = Just b }
+
+-- | parse request body and return params. since 0.9.0.0.
+getReqParams :: MonadIO m => ActionT m [Param]
+getReqParams = fst <$> getRequestBody
+
+-- | parse request body and return files. since 0.9.0.0.
+getReqFiles :: MonadIO m => ActionT m [File L.ByteString]
+getReqFiles = snd <$> getRequestBody
+
 getConfig :: Monad m => ActionT m ApiaryConfig
 getConfig = ActionT $ \c _ s cont -> cont c s
 
@@ -285,9 +330,13 @@
 lbs :: Monad m => L.ByteString -> ActionT m ()
 lbs l = modifyState (\s -> s { actionBody = LBS l } )
 
--- | set response body source. since 0.1.0.0.
-source :: Monad m => Source IO (Flush Builder) -> ActionT m ()
-source src = modifyState (\s -> s { actionBody = SRC src } )
+-- | set response body source. since 0.9.0.0.
+stream :: Monad m => StreamingBody -> ActionT m ()
+stream str = modifyState (\s -> s { actionBody = Str str })
+
+{-# DEPRECATED source "use stream" #-}
+source :: Monad m => StreamingBody -> ActionT m ()
+source = stream
 
 {-# DEPRECATED redirectFound, redirectSeeOther "use redirect" #-}
 -- | redirect with 302 Found. since 0.3.3.0.
diff --git a/src/Control/Monad/Apiary/Filter.hs b/src/Control/Monad/Apiary/Filter.hs
--- a/src/Control/Monad/Apiary/Filter.hs
+++ b/src/Control/Monad/Apiary/Filter.hs
@@ -5,6 +5,7 @@
 {-# LANGUAGE Rank2Types #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 module Control.Monad.Apiary.Filter (
     -- * filters
@@ -42,6 +43,7 @@
     ) where
 
 import Control.Monad
+import Control.Monad.Trans
 import Network.Wai as Wai
 import qualified Network.HTTP.Types as HT
 import Network.HTTP.Types (StdMethod(..))
@@ -107,20 +109,26 @@
 -- query "key" (Proxy :: Proxy ('Option' (Maybe Int)) -- get first \'key\' query parameter as Int. allow without param or value.
 -- query "key" (Proxy :: Proxy ('Many' String) -- get all \'key\' query parameter as String.
 -- @
--- 
-query :: (Query a, Strategy.Strategy w, Functor n, Monad n)
+query :: forall a as w n m b. 
+      (ReqParam a, Strategy.Strategy w, Functor n, MonadIO n)
       => S.ByteString
       -> Proxy (w a)
       -> ApiaryT (Strategy.SNext w as a) n m b
       -> ApiaryT as n m b
-query k p = function $ \l r -> Strategy.readStrategy readQuery ((k ==) . fst) p (queryString r) l
+query key p = focus $ \l -> do
+    r     <- getRequest
+    (q,f) <- getRequestBody
 
+    maybe mzero return $
+        Strategy.readStrategy id ((key ==) . fst) p 
+        (reqParams (Proxy :: Proxy a) r q f) l
+
 -- | get first matched paramerer. since 0.5.0.0.
 --
 -- @
 -- "key" =: pInt == query "key" (pFirst pInt) == query "key" (Proxy :: Proxy (First Int))
 -- @
-(=:) :: (Functor n, Monad n, Query a) => S.ByteString -> Proxy a 
+(=:) :: (Functor n, MonadIO n, ReqParam a) => S.ByteString -> Proxy a 
      -> ApiaryT (Snoc as a) n m b -> ApiaryT as n m b
 k =: t = query k (pFirst t)
 
@@ -131,7 +139,7 @@
 -- @
 -- "key" =: pInt == query "key" (pOne pInt) == query "key" (Proxy :: Proxy (One Int))
 -- @
-(=!:) :: (Functor n, Monad n, Query a) => S.ByteString -> Proxy a 
+(=!:) :: (Functor n, MonadIO n, ReqParam a) => S.ByteString -> Proxy a 
       -> ApiaryT (Snoc as a) n m b -> ApiaryT as n m b
 k =!: t = query k (pOne t)
 
@@ -142,7 +150,7 @@
 -- @
 -- "key" =: pInt == query "key" (pOption pInt) == query "key" (Proxy :: Proxy (Option Int))
 -- @
-(=?:) :: (Functor n, Monad n, Query a) => S.ByteString -> Proxy a 
+(=?:) :: (Functor n, MonadIO n, ReqParam a) => S.ByteString -> Proxy a 
       -> ApiaryT (Snoc as (Maybe a)) n m b -> ApiaryT as n m b
 k =?: t = query k (pOption t)
 
@@ -153,7 +161,7 @@
 -- @
 -- "key" =: pInt == query "key" (pCheck pInt) == query "key" (Proxy :: Proxy (Check Int))
 -- @
-(?:) :: (Functor n, Monad n, Query a) => S.ByteString -> Proxy a 
+(?:) :: (Functor n, MonadIO n, ReqParam a) => S.ByteString -> Proxy a 
      -> ApiaryT as n m b -> ApiaryT as n m b
 k ?: t = query k (pCheck t)
 
@@ -162,7 +170,7 @@
 -- @
 -- "key" =: pInt == query "key" (pMany pInt) == query "key" (Proxy :: Proxy (Many Int))
 -- @
-(=*:) :: (Functor n, Monad n, Query a) => S.ByteString -> Proxy a 
+(=*:) :: (Functor n, MonadIO n, ReqParam a) => S.ByteString -> Proxy a 
       -> ApiaryT (Snoc as [a]) n m b -> ApiaryT as n m b
 k =*: t = query k (pMany t)
 
@@ -171,7 +179,7 @@
 -- @
 -- "key" =: pInt == query "key" (pSome pInt) == query "key" (Proxy :: Proxy (Some Int))
 -- @
-(=+:) :: (Functor n, Monad n, Query a) => S.ByteString -> Proxy a 
+(=+:) :: (Functor n, MonadIO n, ReqParam a) => S.ByteString -> Proxy a 
       -> ApiaryT (Snoc as [a]) n m b -> ApiaryT as n m b
 k =+: t = query k (pSome t)
 
@@ -181,7 +189,7 @@
 -- hasQuery q = 'query' q (Proxy :: Proxy ('Check' ()))
 -- @
 --
-hasQuery :: (Functor n, Monad n) => S.ByteString -> ApiaryT c n m a -> ApiaryT c n m a
+hasQuery :: (Functor n, MonadIO n) => S.ByteString -> ApiaryT c n m a -> ApiaryT c n m a
 hasQuery q = query q (Proxy :: Proxy (Strategy.Check ()))
 
 --------------------------------------------------------------------------------
diff --git a/src/Control/Monad/Apiary/Filter/Internal/Strategy.hs b/src/Control/Monad/Apiary/Filter/Internal/Strategy.hs
--- a/src/Control/Monad/Apiary/Filter/Internal/Strategy.hs
+++ b/src/Control/Monad/Apiary/Filter/Internal/Strategy.hs
@@ -27,7 +27,6 @@
 getQuery :: (v -> Maybe a) -> Proxy (w a) -> ((k,v) -> Bool) -> [(k, v)] -> [Maybe a]
 getQuery readf _ kf = map readf . map snd . filter kf
 
-
 -- | get first matched key( [1,) params to Type.). since 0.5.0.0.
 data Option a
 instance Strategy Option where
diff --git a/src/Data/Apiary/Param.hs b/src/Data/Apiary/Param.hs
--- a/src/Data/Apiary/Param.hs
+++ b/src/Data/Apiary/Param.hs
@@ -6,6 +6,8 @@
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE TupleSections #-}
+{-# LANGUAGE OverlappingInstances #-}
 
 module Data.Apiary.Param where
 
@@ -22,6 +24,9 @@
 import Data.Proxy
 import Data.String(IsString)
 
+import Network.Wai
+import Network.Wai.Parse
+
 jsToBool :: (IsString a, Eq a) => a -> Bool
 jsToBool = flip notElem jsFalse
     where
@@ -149,3 +154,16 @@
 
 pMaybe :: Proxy a -> Proxy (Maybe a)
 pMaybe _ = Proxy
+
+pFile :: Proxy (File L.ByteString)
+pFile = Proxy
+
+class ReqParam a where
+  reqParams :: Proxy a -> Request -> [Param] -> [File L.ByteString] -> [(S.ByteString, Maybe a)]
+
+instance ReqParam (FileInfo L.ByteString) where
+    reqParams _ _ _ f = map (\(k,v) -> (k, Just v)) f
+
+instance Query a => ReqParam a where
+    reqParams _ r p _ = map (\(k,v) -> (k, readQuery v)) (queryString r) ++
+        map (\(k,v) -> (k, readQuery $ Just v)) p
diff --git a/src/Web/Apiary/Wai.hs b/src/Web/Apiary/Wai.hs
new file mode 100644
--- /dev/null
+++ b/src/Web/Apiary/Wai.hs
@@ -0,0 +1,6 @@
+-- | reexporting Network.Wai to reduce dependencies from apiary-* packages.
+module Web.Apiary.Wai
+    ( module Network.Wai
+    ) where
+
+import Network.Wai
diff --git a/test/main.hs b/test/main.hs
--- a/test/main.hs
+++ b/test/main.hs
@@ -153,7 +153,7 @@
   where app = queryApp (=:) (=:) (=:)
 
 queryOneTest :: Test
-queryOneTest = testGroup "First"
+queryOneTest = testGroup "One"
     [ testReq "GET /" $ assert404 app
     , testReq "GET /?foo" $ assertPlain200 "foo Maybe String Nothing" app
     , testReq "GET /?foo&foo=3" $ assert404 app
@@ -165,7 +165,7 @@
   where app = queryApp (=!:) (=!:) (=!:)
 
 queryOptionTest :: Test
-queryOptionTest = testGroup "First"
+queryOptionTest = testGroup "Option"
     [ testReq "GET /" $ assertPlain200 "foo Int Nothing" app
     , testReq "GET /?foo" $ assertPlain200 "foo Maybe String Just Nothing" app
     , testReq "GET /?foo&foo=3" $ assertPlain200 "foo Maybe String Just Nothing" app
@@ -177,7 +177,7 @@
   where app = queryApp (=?:) (=?:) (=?:)
 
 queryCheckTest :: Test
-queryCheckTest = testGroup "First"
+queryCheckTest = testGroup "Check"
     [ testReq "GET /" $ assert404 app
     , testReq "GET /?foo" $ assertPlain200 "foo Maybe String" app
     , testReq "GET /?foo&foo=3" $ assertPlain200 "foo Maybe String" app
@@ -189,7 +189,7 @@
   where app = queryCheckApp
 
 queryManyTest :: Test
-queryManyTest = testGroup "First"
+queryManyTest = testGroup "Many"
     [ testReq "GET /" $ assertPlain200 "foo Int []" app
     , testReq "GET /?foo" $ assertPlain200 "foo Maybe String [Nothing]" app
     , testReq "GET /?foo&foo=3" $ assertPlain200 "foo Maybe String [Nothing,Just \"3\"]" app
@@ -201,7 +201,7 @@
   where app = queryApp (=*:) (=*:) (=*:)
 
 querySomeTest :: Test
-querySomeTest = testGroup "First"
+querySomeTest = testGroup "Some"
     [ testReq "GET /" $ assert404 app
     , testReq "GET /?foo" $ assertPlain200 "foo Maybe String [Nothing]" app
     , testReq "GET /?foo&foo=3" $ assertPlain200 "foo Maybe String [Nothing,Just \"3\"]" app