diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,15 @@
 
 ## [Unreleased]
 
+## [1.2.0] - 2024-03-18
+
+### Added
+- Prerequisite traits (#37)
+- acceptMatch middleware (#39)
+
+### Changed
+- Support for embedding WAI applications in handlers (#36)
+
 ## [1.1.1] - 2024-01-01
 
 ### Changed
@@ -49,7 +58,8 @@
 - Extracted webgear-core from webgear-server
 - New arrow based API
 
-[Unreleased]: https://github.com/haskell-webgear/webgear/compare/v1.1.1...HEAD
+[Unreleased]: https://github.com/haskell-webgear/webgear/compare/v1.2.0...HEAD
+[1.2.0]: https://github.com/haskell-webgear/webgear/releases/tag/v1.2.0
 [1.1.1]: https://github.com/haskell-webgear/webgear/releases/tag/v1.1.1
 [1.1.0]: https://github.com/haskell-webgear/webgear/releases/tag/v1.1.0
 [1.0.5]: https://github.com/haskell-webgear/webgear/releases/tag/v1.0.5
diff --git a/src/WebGear/Core/Handler/Static.hs b/src/WebGear/Core/Handler/Static.hs
--- a/src/WebGear/Core/Handler/Static.hs
+++ b/src/WebGear/Core/Handler/Static.hs
@@ -2,65 +2,22 @@
  Handlers for serving static resources
 -}
 module WebGear.Core.Handler.Static (
-  serveDir,
-  serveFile,
+  serveStatic,
 ) where
 
-import Control.Arrow ((<<<))
-import qualified Data.Text as Text
-import qualified Network.Mime as Mime
-import System.FilePath (joinPath, takeFileName, (</>))
-import WebGear.Core.Handler (Handler (..), RoutePath (..), unwitnessA, (>->))
-import WebGear.Core.Request (Request (..))
-import WebGear.Core.Response (Response, ResponseBody (..))
-import WebGear.Core.Trait (Sets, With)
-import WebGear.Core.Trait.Body (UnknownContentBody, setBodyWithoutContentType)
-import WebGear.Core.Trait.Header (RequiredResponseHeader, setHeader)
-import WebGear.Core.Trait.Status (Status, notFound404, ok200)
+import Control.Arrow (returnA)
+import Network.Wai (Request (..))
+import qualified Network.Wai.Application.Static as Wai.Static
+import WebGear.Core.Handler (Handler (..), RequestHandler, RoutePath (..))
+import WebGear.Core.Request (toWaiRequest)
+import WebGear.Core.Response (Response (ResponseCont))
+import WebGear.Core.Trait (unwitness)
 import Prelude hiding (readFile)
 
--- | Serve files under the specified directory.
-serveDir ::
-  ( Handler h m
-  , Sets
-      h
-      [ Status
-      , RequiredResponseHeader "Content-Type" Mime.MimeType
-      , UnknownContentBody
-      ]
-      Response
-  ) =>
-  -- | The directory to serve
-  FilePath ->
-  -- | Optional index filename for the root directory. A 404 Not Found
-  -- response will be returned for requests to the root path if this
-  -- is set to @Nothing@.
-  Maybe FilePath ->
-  h (Request `With` ts) Response
-serveDir root index = proc _request -> consumeRoute go -< ()
-  where
-    go = proc path -> do
-      case (path, index) of
-        (RoutePath [], Nothing) -> unwitnessA <<< notFound404 -< ()
-        (RoutePath [], Just f) -> serveFile -< root </> f
-        (RoutePath ps, _) -> serveFile -< root </> joinPath (Text.unpack <$> ps)
-
--- | Serve a file specified by the input filepath.
-serveFile ::
-  ( Handler h m
-  , Sets
-      h
-      [ Status
-      , RequiredResponseHeader "Content-Type" Mime.MimeType
-      , UnknownContentBody
-      ]
-      Response
-  ) =>
-  h FilePath Response
-serveFile = proc file -> do
-  let contents = ResponseBodyFile file Nothing
-      contentType = Mime.defaultMimeLookup $ Text.pack $ takeFileName file
-  (ok200 -< ())
-    >-> (\resp -> setBodyWithoutContentType -< (resp, contents))
-    >-> (\resp -> setHeader @"Content-Type" -< (resp, contentType))
-    >-> (\resp -> unwitnessA -< resp)
+-- | Serve static assets
+serveStatic :: (Handler h m) => Wai.Static.StaticSettings -> RequestHandler h ts
+serveStatic settings =
+  proc request -> do
+    RoutePath pathInfo <- consumeRoute returnA -< ()
+    let waiRequest = toWaiRequest $ unwitness request
+    returnA -< ResponseCont $ Wai.Static.staticApp settings waiRequest{pathInfo}
diff --git a/src/WebGear/Core/Response.hs b/src/WebGear/Core/Response.hs
--- a/src/WebGear/Core/Response.hs
+++ b/src/WebGear/Core/Response.hs
@@ -5,39 +5,21 @@
   -- * Basic Types
   Response (..),
   ResponseBody (..),
-  toWaiResponse,
 ) where
 
 import qualified Data.Binary.Builder as B
+import Data.ByteString (ByteString)
 import qualified Network.HTTP.Types as HTTP
 import qualified Network.Wai as Wai
 
-{- | An HTTP response sent from the server to the client.
-
-The response contains a status, optional headers and an optional
-body payload.
--}
-data Response = Response
-  { responseStatus :: HTTP.Status
-  -- ^ Response status code
-  , responseHeaders :: HTTP.ResponseHeaders
-  -- ^ Response headers
-  , responseBody :: ResponseBody
-  -- ^ The response body
-  }
+-- | An HTTP response sent from the server to the client.
+data Response
+  = Response HTTP.Status HTTP.ResponseHeaders ResponseBody
+  | ResponseRaw (IO ByteString -> (ByteString -> IO ()) -> IO ()) Wai.Response
+  | ResponseCont ((Wai.Response -> IO Wai.ResponseReceived) -> IO Wai.ResponseReceived)
 
+-- | HTTP response body
 data ResponseBody
   = ResponseBodyFile FilePath (Maybe Wai.FilePart)
   | ResponseBodyBuilder B.Builder
   | ResponseBodyStream Wai.StreamingBody
-
--- | Generate a WAI response
-toWaiResponse :: Response -> Wai.Response
-toWaiResponse Response{..} =
-  case responseBody of
-    ResponseBodyFile fpath fpart ->
-      Wai.responseFile responseStatus responseHeaders fpath fpart
-    ResponseBodyBuilder builder ->
-      Wai.responseBuilder responseStatus responseHeaders builder
-    ResponseBodyStream stream ->
-      Wai.responseStream responseStatus responseHeaders stream
diff --git a/src/WebGear/Core/Trait.hs b/src/WebGear/Core/Trait.hs
--- a/src/WebGear/Core/Trait.hs
+++ b/src/WebGear/Core/Trait.hs
@@ -47,6 +47,7 @@
   -- * Core Types
   Trait (..),
   TraitAbsence (..),
+  Prerequisite,
   Get (..),
   Gets,
   Set (..),
@@ -84,10 +85,21 @@
   -- value. This could be an error message, exception etc.
   type Absence t a :: Type
 
+{- | Indicates the constraints a trait depends upon as a
+prerequisite. This is used to assert that a trait @t@ can be
+extracted from a value @a@ only if one or more other traits are
+present in the trait list @ts@ associated with it.
+
+If a trait does not depend on other traits this can be set to the
+empty contraint @()@.
+-}
+type family Prerequisite (t :: Type) (ts :: [Type]) (a :: Type) :: Constraint
+
 -- | Extract trait attributes from a value.
 class (Arrow h, TraitAbsence t a) => Get h t a where
   -- | Attempt to witness the trait attribute from the value @a@.
   getTrait ::
+    (Prerequisite t ts a) =>
     -- | The trait to witness
     t ->
     -- | Arrow that attemtps to witness the trait and can possibly
@@ -168,7 +180,7 @@
 -}
 probe ::
   forall t ts h a.
-  (Get h t a) =>
+  (Get h t a, Prerequisite t ts a) =>
   t ->
   h (a `With` ts) (Either (Absence t a) (a `With` (t : ts)))
 probe t = proc l -> do
diff --git a/src/WebGear/Core/Trait/Auth/Basic.hs b/src/WebGear/Core/Trait/Auth/Basic.hs
--- a/src/WebGear/Core/Trait/Auth/Basic.hs
+++ b/src/WebGear/Core/Trait/Auth/Basic.hs
@@ -136,8 +136,15 @@
 instance TraitAbsence (BasicAuth' Optional scheme m e a) Request where
   type Absence (BasicAuth' Optional scheme m e a) Request = Void
 
+type instance
+  Prerequisite (BasicAuth' x scheme m e a) ts Request =
+    HasTrait (AuthorizationHeader scheme) ts
+
 basicAuthMiddleware ::
-  (Get h (BasicAuth' x scheme m e t) Request, ArrowChoice h) =>
+  ( ArrowChoice h
+  , Get h (BasicAuth' x scheme m e t) Request
+  , HasTrait (AuthorizationHeader scheme) ts
+  ) =>
   BasicAuth' x scheme m e t ->
   h (Request `With` ts, Absence (BasicAuth' x scheme m e t) Request) Response ->
   Middleware h ts (BasicAuth' x scheme m e t : ts)
@@ -161,7 +168,10 @@
 -}
 basicAuth ::
   forall m e t h ts.
-  (Get h (BasicAuth' Required "Basic" m e t) Request, ArrowChoice h) =>
+  ( ArrowChoice h
+  , Get h (BasicAuth' Required "Basic" m e t) Request
+  , HasTrait (AuthorizationHeader "Basic") ts
+  ) =>
   -- | Authentication configuration
   BasicAuth m e t ->
   -- | Error handler
@@ -178,7 +188,10 @@
 -}
 basicAuth' ::
   forall scheme m e t h ts.
-  (Get h (BasicAuth' Required scheme m e t) Request, ArrowChoice h) =>
+  ( ArrowChoice h
+  , Get h (BasicAuth' Required scheme m e t) Request
+  , HasTrait (AuthorizationHeader scheme) ts
+  ) =>
   -- | Authentication configuration
   BasicAuth' Required scheme m e t ->
   -- | Error handler
@@ -200,7 +213,10 @@
 -}
 optionalBasicAuth ::
   forall m e t h ts.
-  (Get h (BasicAuth' Optional "Basic" m e t) Request, ArrowChoice h) =>
+  ( ArrowChoice h
+  , Get h (BasicAuth' Optional "Basic" m e t) Request
+  , HasTrait (AuthorizationHeader "Basic") ts
+  ) =>
   -- | Authentication configuration
   BasicAuth' Optional "Basic" m e t ->
   Middleware h ts (BasicAuth' Optional "Basic" m e t : ts)
@@ -216,7 +232,10 @@
 -}
 optionalBasicAuth' ::
   forall scheme m e t h ts.
-  (Get h (BasicAuth' Optional scheme m e t) Request, ArrowChoice h) =>
+  ( ArrowChoice h
+  , Get h (BasicAuth' Optional scheme m e t) Request
+  , HasTrait (AuthorizationHeader scheme) ts
+  ) =>
   -- | Authentication configuration
   BasicAuth' Optional scheme m e t ->
   Middleware h ts (BasicAuth' Optional scheme m e t : ts)
diff --git a/src/WebGear/Core/Trait/Auth/Common.hs b/src/WebGear/Core/Trait/Auth/Common.hs
--- a/src/WebGear/Core/Trait/Auth/Common.hs
+++ b/src/WebGear/Core/Trait/Auth/Common.hs
@@ -3,13 +3,11 @@
 -}
 module WebGear.Core.Trait.Auth.Common (
   AuthorizationHeader,
-  getAuthorizationHeaderTrait,
   Realm (..),
   AuthToken (..),
   respondUnauthorized,
 ) where
 
-import Control.Arrow (returnA)
 import Data.ByteString (ByteString, drop)
 import Data.ByteString.Char8 (break)
 import Data.CaseInsensitive (CI, mk, original)
@@ -17,15 +15,13 @@
 import Data.String (IsString (..))
 import Data.Text (Text)
 import Data.Text.Encoding (decodeUtf8, encodeUtf8)
-import Data.Void (absurd)
 import GHC.TypeLits (KnownSymbol, Symbol, symbolVal)
 import Web.HttpApiData (FromHttpApiData (..))
 import WebGear.Core.Handler (Handler, unwitnessA, (>->))
 import WebGear.Core.MIMETypes (PlainText (..))
 import WebGear.Core.Modifiers (Existence (..), ParseStyle (..))
-import WebGear.Core.Request (Request)
 import WebGear.Core.Response (Response)
-import WebGear.Core.Trait (Get (..), Sets, With)
+import WebGear.Core.Trait (Sets)
 import WebGear.Core.Trait.Body (Body, setBody)
 import WebGear.Core.Trait.Header (RequestHeader (..), RequiredResponseHeader, setHeader)
 import WebGear.Core.Trait.Status (Status, unauthorized401)
@@ -34,20 +30,6 @@
 -- | Trait for \"Authorization\" header
 type AuthorizationHeader scheme = RequestHeader Optional Lenient "Authorization" (AuthToken scheme)
 
-{- | Extract the \"Authorization\" header from a request by specifying
-   an authentication scheme.
-
-  The header is split into the scheme and token parts and returned.
--}
-getAuthorizationHeaderTrait ::
-  forall scheme h ts.
-  (Get h (AuthorizationHeader scheme) Request) =>
-  h (Request `With` ts) (Maybe (Either Text (AuthToken scheme)))
-getAuthorizationHeaderTrait = proc request -> do
-  result <- getTrait (RequestHeader :: RequestHeader Optional Lenient "Authorization" (AuthToken scheme)) -< request
-  returnA -< either absurd id result
-{-# INLINE getAuthorizationHeaderTrait #-}
-
 -- | The protection space for authentication
 newtype Realm = Realm ByteString
   deriving newtype (Eq, Ord, Show, Read, IsString)
@@ -61,9 +43,12 @@
   }
 
 instance (KnownSymbol scheme) => FromHttpApiData (AuthToken scheme) where
+  {-# INLINE parseUrlPiece #-}
+  parseUrlPiece :: Text -> Either Text (AuthToken scheme)
   parseUrlPiece = parseHeader . encodeUtf8
 
   {-# INLINE parseHeader #-}
+  parseHeader :: ByteString -> Either Text (AuthToken scheme)
   parseHeader hdr =
     case break (== ' ') hdr of
       (scm, tok) ->
diff --git a/src/WebGear/Core/Trait/Auth/JWT.hs b/src/WebGear/Core/Trait/Auth/JWT.hs
--- a/src/WebGear/Core/Trait/Auth/JWT.hs
+++ b/src/WebGear/Core/Trait/Auth/JWT.hs
@@ -128,6 +128,10 @@
 instance TraitAbsence (JWTAuth' Optional scheme m e a) Request where
   type Absence (JWTAuth' Optional scheme m e a) Request = Void
 
+type instance
+  Prerequisite (JWTAuth' x scheme m e a) ts Request =
+    HasTrait (AuthorizationHeader scheme) ts
+
 {- | Middleware to add JWT authentication protection for a
  handler. Expects the JWT to be available via a standard bearer
  authorization header in the format:
@@ -143,8 +147,9 @@
  retrieved successfully.
 -}
 jwtAuth ::
-  ( Get h (JWTAuth m e t) Request
-  , ArrowChoice h
+  ( ArrowChoice h
+  , Get h (JWTAuth m e t) Request
+  , HasTrait (AuthorizationHeader "Bearer") ts
   ) =>
   -- | Authentication configuration
   JWTAuth m e t ->
@@ -170,8 +175,9 @@
  authentication error appropriately.
 -}
 optionalJWTAuth ::
-  ( Get h (JWTAuth' Optional "Bearer" m e t) Request
-  , ArrowChoice h
+  ( ArrowChoice h
+  , Get h (JWTAuth' Optional "Bearer" m e t) Request
+  , HasTrait (AuthorizationHeader "Bearer") ts
   ) =>
   -- | Authentication configuration
   JWTAuth' Optional "Bearer" m e t ->
@@ -180,13 +186,14 @@
 {-# INLINE optionalJWTAuth #-}
 
 jwtAuthMiddleware ::
-  forall s e t x h m ts.
-  ( Get h (JWTAuth' x s m e t) Request
-  , ArrowChoice h
+  forall scheme e t x h m ts.
+  ( ArrowChoice h
+  , Get h (JWTAuth' x scheme m e t) Request
+  , HasTrait (AuthorizationHeader scheme) ts
   ) =>
-  JWTAuth' x s m e t ->
-  h (Request `With` ts, Absence (JWTAuth' x s m e t) Request) Response ->
-  Middleware h ts (JWTAuth' x s m e t : ts)
+  JWTAuth' x scheme m e t ->
+  h (Request `With` ts, Absence (JWTAuth' x scheme m e t) Request) Response ->
+  Middleware h ts (JWTAuth' x scheme m e t : ts)
 jwtAuthMiddleware authCfg errorHandler nextHandler =
   proc request -> do
     result <- probe authCfg -< request
@@ -210,15 +217,16 @@
  retrieved successfully.
 -}
 jwtAuth' ::
-  forall s e t h m ts.
-  ( Get h (JWTAuth' Required s m e t) Request
-  , ArrowChoice h
+  forall scheme e t h m ts.
+  ( ArrowChoice h
+  , Get h (JWTAuth' Required scheme m e t) Request
+  , HasTrait (AuthorizationHeader scheme) ts
   ) =>
   -- | Authentication configuration
-  JWTAuth' Required s m e t ->
+  JWTAuth' Required scheme m e t ->
   -- | Error handler
   h (Request `With` ts, JWTAuthError e) Response ->
-  Middleware h ts (JWTAuth' Required s m e t : ts)
+  Middleware h ts (JWTAuth' Required scheme m e t : ts)
 jwtAuth' = jwtAuthMiddleware
 {-# INLINE jwtAuth' #-}
 
@@ -238,12 +246,13 @@
  authentication error appropriately.
 -}
 optionalJWTAuth' ::
-  forall s e t h m ts.
-  ( Get h (JWTAuth' Optional s m e t) Request
-  , ArrowChoice h
+  forall scheme e t h m ts.
+  ( ArrowChoice h
+  , Get h (JWTAuth' Optional scheme m e t) Request
+  , HasTrait (AuthorizationHeader scheme) ts
   ) =>
   -- | Authentication configuration
-  JWTAuth' Optional s m e t ->
-  Middleware h ts (JWTAuth' Optional s m e t : ts)
+  JWTAuth' Optional scheme m e t ->
+  Middleware h ts (JWTAuth' Optional scheme m e t : ts)
 optionalJWTAuth' cfg = jwtAuthMiddleware cfg $ arr (absurd . snd)
 {-# INLINE optionalJWTAuth' #-}
diff --git a/src/WebGear/Core/Trait/Body.hs b/src/WebGear/Core/Trait/Body.hs
--- a/src/WebGear/Core/Trait/Body.hs
+++ b/src/WebGear/Core/Trait/Body.hs
@@ -37,6 +37,7 @@
 import WebGear.Core.Response (Response, ResponseBody)
 import WebGear.Core.Trait (
   Get,
+  Prerequisite,
   Set,
   Sets,
   Trait (..),
@@ -57,6 +58,8 @@
 instance TraitAbsence (Body mt t) Request where
   type Absence (Body mt t) Request = Text
 
+type instance Prerequisite (Body mt t) ts Request = ()
+
 instance Trait (Body mt t) Response where
   type Attribute (Body mt t) Response = t
 
@@ -74,7 +77,7 @@
  Usage:
 
 @
- requestBody \@'Text' 'PlainText' errorHandler nextHandler
+ requestBody \@'Text' 'WebGear.Core.MIMETypes.PlainText' errorHandler nextHandler
 @
 -}
 requestBody ::
@@ -102,7 +105,7 @@
 
 @
  let body :: SomeJSONType = ...
- response' <- setBody 'JSON' -< (response, body)
+ response' <- setBody 'WebGear.Core.MIMETypes.JSON' -< (response, body)
 @
 -}
 setBody ::
@@ -142,7 +145,7 @@
 
 @
  let body :: SomeJSONType = ...
- respondA 'HTTP.ok200' 'JSON' -< body
+ respondA 'HTTP.ok200' 'WebGear.Core.MIMETypes.JSON' -< body
 @
 -}
 respondA ::
diff --git a/src/WebGear/Core/Trait/Cookie.hs b/src/WebGear/Core/Trait/Cookie.hs
--- a/src/WebGear/Core/Trait/Cookie.hs
+++ b/src/WebGear/Core/Trait/Cookie.hs
@@ -19,10 +19,21 @@
 import GHC.TypeLits (Symbol)
 import qualified Web.Cookie as Cookie
 import WebGear.Core.Handler (Middleware)
-import WebGear.Core.Modifiers (Existence (..))
+import WebGear.Core.Modifiers (Existence (..), ParseStyle (..))
 import WebGear.Core.Request (Request)
 import WebGear.Core.Response (Response)
-import WebGear.Core.Trait (Get, Set, Trait (..), TraitAbsence (..), With, plant, probe)
+import WebGear.Core.Trait (
+  Get,
+  HasTrait,
+  Prerequisite,
+  Set,
+  Trait (..),
+  TraitAbsence (..),
+  With,
+  plant,
+  probe,
+ )
+import WebGear.Core.Trait.Header (RequestHeader)
 
 -- | Indicates a missing cookie
 data CookieNotFound = CookieNotFound
@@ -38,6 +49,10 @@
 instance Trait (Cookie Required name val) Request where
   type Attribute (Cookie Required name val) Request = val
 
+type instance
+  Prerequisite (Cookie e name val) ts Request =
+    HasTrait (RequestHeader e Strict "Cookie" Text) ts
+
 instance TraitAbsence (Cookie Required name val) Request where
   type Absence (Cookie Required name val) Request = Either CookieNotFound CookieParseError
 
@@ -49,7 +64,10 @@
 
 cookieHandler ::
   forall name val e h ts.
-  (Get h (Cookie e name val) Request, ArrowChoice h) =>
+  ( ArrowChoice h
+  , Get h (Cookie e name val) Request
+  , HasTrait (RequestHeader e Strict "Cookie" Text) ts
+  ) =>
   -- | error handler
   h (Request `With` ts, Absence (Cookie e name val) Request) Response ->
   Middleware h ts (Cookie e name val : ts)
@@ -70,7 +88,10 @@
 -}
 cookie ::
   forall name val h ts.
-  (Get h (Cookie Required name val) Request, ArrowChoice h) =>
+  ( ArrowChoice h
+  , Get h (Cookie Required name val) Request
+  , HasTrait (RequestHeader Required Strict "Cookie" Text) ts
+  ) =>
   -- | Error handler
   h (Request `With` ts, Either CookieNotFound CookieParseError) Response ->
   Middleware h ts (Cookie Required name val : ts)
@@ -88,7 +109,10 @@
 -}
 optionalCookie ::
   forall name val h ts.
-  (Get h (Cookie Optional name val) Request, ArrowChoice h) =>
+  ( ArrowChoice h
+  , Get h (Cookie Optional name val) Request
+  , HasTrait (RequestHeader Optional Strict "Cookie" Text) ts
+  ) =>
   -- | Error handler
   h (Request `With` ts, CookieParseError) Response ->
   Middleware h ts (Cookie Optional name val : ts)
diff --git a/src/WebGear/Core/Trait/Header.hs b/src/WebGear/Core/Trait/Header.hs
--- a/src/WebGear/Core/Trait/Header.hs
+++ b/src/WebGear/Core/Trait/Header.hs
@@ -43,25 +43,33 @@
   optionalLenientHeader,
   setHeader,
   setOptionalHeader,
+  acceptMatch,
 ) where
 
 import Control.Arrow (ArrowChoice, arr)
+import Control.Arrow.Operations (ArrowError)
 import Data.Kind (Type)
+import Data.Maybe (fromMaybe)
 import Data.Text (Text)
 import Data.Void (Void, absurd)
 import GHC.TypeLits (Symbol)
-import WebGear.Core.Handler (Middleware)
+import qualified Network.HTTP.Media as HTTP
+import qualified Network.HTTP.Types as HTTP
+import WebGear.Core.Handler (Middleware, RouteMismatch, routeMismatch)
+import WebGear.Core.MIMETypes (MIMEType (..))
 import WebGear.Core.Modifiers (Existence (..), ParseStyle (..))
-import WebGear.Core.Request (Request)
+import WebGear.Core.Request (Request, requestHeader)
 import WebGear.Core.Response (Response)
 import WebGear.Core.Trait (
   Get (..),
+  Prerequisite,
   Set,
   Trait (..),
   TraitAbsence (..),
   With,
   plant,
   probe,
+  unwitness,
  )
 
 -- | Indicates a missing header
@@ -79,10 +87,10 @@
 -}
 data RequestHeader (e :: Existence) (p :: ParseStyle) (name :: Symbol) (val :: Type) = RequestHeader
 
--- | A `Header` that is required in the request and parsed strictly
+-- | A `RequestHeader` that is required and parsed strictly
 type RequiredRequestHeader = RequestHeader Required Strict
 
--- | A `Header` that is optional in the request and parsed strictly
+-- | A `RequestHeader` that is optional and parsed strictly
 type OptionalRequestHeader = RequestHeader Optional Strict
 
 instance Trait (RequestHeader Required Strict name val) Request where
@@ -109,6 +117,8 @@
 instance TraitAbsence (RequestHeader Optional Lenient name val) Request where
   type Absence (RequestHeader Optional Lenient name val) Request = Void
 
+type instance Prerequisite (RequestHeader e p name val) ts Request = ()
+
 headerHandler ::
   forall name val e p h ts.
   (Get h (RequestHeader e p name val) Request, ArrowChoice h) =>
@@ -195,16 +205,16 @@
 {-# INLINE optionalLenientHeader #-}
 
 {- | A 'Trait' for setting a header in the HTTP response. It has a
- specified @name@ and a value of type @val@ which can be converted to
- a 'ByteString'. The header name is compared case-insensitively. The
- modifier @e@ determines whether the header is mandatory or optional.
+ specified @name@ and a value of type @val@. The header name is
+ compared case-insensitively. The modifier @e@ determines whether the
+ header is mandatory or optional.
 -}
 data ResponseHeader (e :: Existence) (name :: Symbol) (val :: Type) = ResponseHeader
 
--- | A `Header` that is required in the response
+-- | A `ResponseHeader` that is required
 type RequiredResponseHeader = ResponseHeader Required
 
--- | A `Header` that is optional in the response
+-- | A `ResponseHeader` that is optional
 type OptionalResponseHeader = ResponseHeader Optional
 
 instance Trait (ResponseHeader Required name val) Response where
@@ -242,3 +252,20 @@
   h (Response `With` ts, Maybe val) (Response `With` (ResponseHeader Optional name val : ts))
 setOptionalHeader = plant ResponseHeader
 {-# INLINE setOptionalHeader #-}
+
+{- | Match the Accept header of the incoming request with the specified mediatype. Another handler will be tried
+ if the match fails.
+
+ Example usage:
+
+ @
+   acceptMatch 'WebGear.Core.MIMETypes.JSON' handler
+ @
+-}
+acceptMatch :: (ArrowChoice h, ArrowError RouteMismatch h, MIMEType mt) => mt -> Middleware h ts ts
+acceptMatch mt nextHandler =
+  proc request -> do
+    let acceptHeader = fromMaybe "*/*" $ requestHeader HTTP.hAccept $ unwitness request
+    case HTTP.matchAccept [mimeType mt] acceptHeader of
+      Just _ -> nextHandler -< request
+      Nothing -> routeMismatch -< ()
diff --git a/src/WebGear/Core/Trait/Method.hs b/src/WebGear/Core/Trait/Method.hs
--- a/src/WebGear/Core/Trait/Method.hs
+++ b/src/WebGear/Core/Trait/Method.hs
@@ -10,7 +10,7 @@
 import qualified Network.HTTP.Types as HTTP
 import WebGear.Core.Handler (Middleware, RouteMismatch, routeMismatch)
 import WebGear.Core.Request (Request)
-import WebGear.Core.Trait (Get (..), Trait (..), TraitAbsence (..), probe)
+import WebGear.Core.Trait (Get (..), Prerequisite, Trait (..), TraitAbsence (..), probe)
 
 -- | A 'Trait' for capturing the HTTP method of a request
 newtype Method = Method HTTP.StdMethod
@@ -26,6 +26,8 @@
 
 instance TraitAbsence Method Request where
   type Absence Method Request = MethodMismatch
+
+type instance Prerequisite Method ts Request = ()
 
 {- | Check whether the request has a specified HTTP method.
 
diff --git a/src/WebGear/Core/Trait/Path.hs b/src/WebGear/Core/Trait/Path.hs
--- a/src/WebGear/Core/Trait/Path.hs
+++ b/src/WebGear/Core/Trait/Path.hs
@@ -29,7 +29,7 @@
 import Language.Haskell.TH.Syntax (Exp (..), Lit (..), Q, TyLit (StrTyLit), Type (..), mkName)
 import WebGear.Core.Handler (Middleware, RouteMismatch, routeMismatch)
 import WebGear.Core.Request (Request)
-import WebGear.Core.Trait (Get, Trait (..), TraitAbsence (..), probe)
+import WebGear.Core.Trait (Get, Prerequisite, Trait (..), TraitAbsence (..), probe)
 import WebGear.Core.Trait.Method (method)
 import Prelude hiding (drop, filter, take)
 
@@ -44,6 +44,8 @@
 instance TraitAbsence Path Request where
   type Absence Path Request = ()
 
+type instance Prerequisite Path ts Request = ()
+
 {- | A path variable that is extracted and converted to a value of
  type @val@. The @tag@ is usually a type-level symbol (string) to
  uniquely identify this variable.
@@ -60,6 +62,8 @@
 instance TraitAbsence (PathVar tag val) Request where
   type Absence (PathVar tag val) Request = PathVarError
 
+type instance Prerequisite (PathVar tag val) ts Request = ()
+
 -- | Trait to indicate that no more path components are present in the request
 data PathEnd = PathEnd
 
@@ -68,6 +72,8 @@
 
 instance TraitAbsence PathEnd Request where
   type Absence PathEnd Request = ()
+
+type instance Prerequisite PathEnd ts Request = ()
 
 {- | A middleware that literally matches path @s@.
 
diff --git a/src/WebGear/Core/Trait/QueryParam.hs b/src/WebGear/Core/Trait/QueryParam.hs
--- a/src/WebGear/Core/Trait/QueryParam.hs
+++ b/src/WebGear/Core/Trait/QueryParam.hs
@@ -43,7 +43,7 @@
 import WebGear.Core.Modifiers (Existence (..), ParseStyle (..))
 import WebGear.Core.Request (Request)
 import WebGear.Core.Response (Response)
-import WebGear.Core.Trait (Get, Trait (..), TraitAbsence (..), With, probe)
+import WebGear.Core.Trait (Get, Prerequisite, Trait (..), TraitAbsence (..), With, probe)
 
 {- | Capture a query parameter with a specified @name@ and convert it to
  a value of type @val@. The type parameter @e@ denotes whether the
@@ -90,6 +90,8 @@
 
 instance TraitAbsence (QueryParam Optional Lenient name val) Request where
   type Absence (QueryParam Optional Lenient name val) Request = Void
+
+type instance Prerequisite (QueryParam e p name val) ts Request = ()
 
 queryParamHandler ::
   forall name val e p h ts.
diff --git a/webgear-core.cabal b/webgear-core.cabal
--- a/webgear-core.cabal
+++ b/webgear-core.cabal
@@ -1,7 +1,7 @@
 cabal-version:       2.4
 
 name:                webgear-core
-version:             1.1.1
+version:             1.2.0
 synopsis:            Composable, type-safe library to build HTTP APIs
 description:
         WebGear is a library to for building composable, type-safe HTTP APIs.
@@ -53,20 +53,20 @@
                       TypeApplications
                       TypeFamilies
                       TypeOperators
-  build-depends:      base >=4.13.0.0 && <4.19
+  build-depends:      base >=4.13.0.0 && <4.20
                     , binary >= 0.8.0.0 && <0.9
                     , bytestring >=0.10.10.1 && <0.13
                     , case-insensitive ==1.2.*
-                    , cookie >=0.4.5 && <0.5
-                    , filepath >=1.4.2.1 && <1.6
+                    , cookie >=0.4.5 && <0.6
                     , http-api-data >=0.4.2 && <0.7
                     , http-media ==0.8.*
                     , http-types ==0.12.*
                     , network ==3.1.*
                     , tagged ==0.8.*
-                    , template-haskell >=2.15.0.0 && <2.21
+                    , template-haskell >=2.15.0.0 && <2.22
                     , text >=1.2.0.0 && <2.2
                     , wai ==3.2.*
+                    , wai-app-static ==3.1.*
                     , wai-extra ==3.1.*
   ghc-options:        -Wall
                       -Wno-unticked-promoted-constructors
@@ -108,4 +108,3 @@
   hs-source-dirs:     src
   build-depends:      arrows ==0.4.*
                     , jose >=0.8.3.1 && <0.12
-                    , mime-types ==0.1.*