diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,13 @@
 # Changelog for hs-opentelemetry-instrumentation-yesod
 
+## Unreleased changes
+
+## 0.1.0.0
+
+### Breaking changes
+
+- Use `HashMap Text Attribute` instead of `[(Text, Attribute)]` as attributes
+
 ## 0.0.1.1
 
 - Bump version bounds for hs-opentelemetry-api to == 0.0.2.0
@@ -7,4 +15,3 @@
 ## 0.0.1.0
 
 - Initial release
-## Unreleased changes
diff --git a/Setup.hs b/Setup.hs
--- a/Setup.hs
+++ b/Setup.hs
@@ -1,2 +1,4 @@
 import Distribution.Simple
+
+
 main = defaultMain
diff --git a/hs-opentelemetry-instrumentation-yesod.cabal b/hs-opentelemetry-instrumentation-yesod.cabal
--- a/hs-opentelemetry-instrumentation-yesod.cabal
+++ b/hs-opentelemetry-instrumentation-yesod.cabal
@@ -1,22 +1,22 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.34.4.
+-- This file has been generated from package.yaml by hpack version 0.35.2.
 --
 -- see: https://github.com/sol/hpack
 
-name:           hs-opentelemetry-instrumentation-yesod
-version:        0.0.1.3
-synopsis:       Yesod middleware for providing OpenTelemetry instrumentation
-description:    Please see the README on GitHub at <https://github.com/iand675/hs-opentelemetry/tree/main/instrumentation/yesod#readme>
-category:       OpenTelemetry, Web
-homepage:       https://github.com/iand675/hs-opentelemetry#readme
-bug-reports:    https://github.com/iand675/hs-opentelemetry/issues
-author:         Ian Duncan
-maintainer:     ian@iankduncan.com
-copyright:      2021 Ian Duncan
-license:        BSD3
-license-file:   LICENSE
-build-type:     Simple
+name:               hs-opentelemetry-instrumentation-yesod
+version:            0.1.0.0
+synopsis:           Yesod middleware for providing OpenTelemetry instrumentation
+description:        Please see the README on GitHub at <https://github.com/iand675/hs-opentelemetry/tree/main/instrumentation/yesod#readme>
+category:           OpenTelemetry, Web
+homepage:           https://github.com/iand675/hs-opentelemetry#readme
+bug-reports:        https://github.com/iand675/hs-opentelemetry/issues
+author:             Ian Duncan, Jade Lovelace
+maintainer:         ian@iankduncan.com
+copyright:          2023 Ian Duncan, Mercury Technologies
+license:            BSD3
+license-file:       LICENSE
+build-type:         Simple
 extra-source-files:
     README.md
     ChangeLog.md
@@ -35,13 +35,14 @@
   ghc-options: -Wall
   build-depends:
       base >=4.7 && <5
-    , hs-opentelemetry-api ==0.0.3.*
-    , hs-opentelemetry-instrumentation-wai ==0.0.1.*
+    , hs-opentelemetry-api ==0.1.*
+    , hs-opentelemetry-instrumentation-wai >=0.0.1 && <0.2
     , microlens
     , mtl
     , template-haskell
     , text
     , unliftio
+    , unordered-containers
     , wai
     , yesod-core
   default-language: Haskell2010
@@ -56,14 +57,15 @@
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       base >=4.7 && <5
-    , hs-opentelemetry-api ==0.0.3.*
-    , hs-opentelemetry-instrumentation-wai ==0.0.1.*
+    , hs-opentelemetry-api ==0.1.*
+    , hs-opentelemetry-instrumentation-wai >=0.0.1 && <0.2
     , hs-opentelemetry-instrumentation-yesod
     , microlens
     , mtl
     , template-haskell
     , text
     , unliftio
+    , unordered-containers
     , wai
     , yesod-core
   default-language: Haskell2010
diff --git a/src/OpenTelemetry/Instrumentation/Yesod.hs b/src/OpenTelemetry/Instrumentation/Yesod.hs
--- a/src/OpenTelemetry/Instrumentation/Yesod.hs
+++ b/src/OpenTelemetry/Instrumentation/Yesod.hs
@@ -1,55 +1,64 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TemplateHaskell #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
-module OpenTelemetry.Instrumentation.Yesod
-  (
+
+module OpenTelemetry.Instrumentation.Yesod (
   -- * Middleware functionality
   openTelemetryYesodMiddleware,
-  RouteRenderer(..),
+  RouteRenderer (..),
   mkRouteToRenderer,
   mkRouteToPattern,
+
   -- * Utilities
   rheSiteL,
-  handlerEnvL
-  ) where
+  handlerEnvL,
+) where
 
+import qualified Data.HashMap.Strict as H
+import Data.List (intercalate)
 import Data.Maybe (catMaybes)
+import Data.Text (Text)
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as T
+import Language.Haskell.TH.Syntax
 import Lens.Micro
+import Network.Wai (requestHeaders)
 import qualified OpenTelemetry.Context as Context
 import OpenTelemetry.Context.ThreadLocal
+import OpenTelemetry.Contrib.SpanTraversals
+import OpenTelemetry.Instrumentation.Wai (requestContext)
 import OpenTelemetry.Trace.Core hiding (inSpan, inSpan', inSpan'')
 import OpenTelemetry.Trace.Monad
+import UnliftIO.Exception
 import Yesod.Core
 import Yesod.Core.Types
-import Language.Haskell.TH.Syntax
-import Network.Wai (requestHeaders)
 import Yesod.Routes.TH.Types
-import UnliftIO.Exception
-import Data.Text (Text)
-import Data.List (intercalate)
 
+
 handlerEnvL :: Lens' (HandlerData child site) (RunHandlerEnv child site)
-handlerEnvL = lens handlerEnv (\h e -> h { handlerEnv = e })
+handlerEnvL = lens handlerEnv (\h e -> h {handlerEnv = e})
 {-# INLINE handlerEnvL #-}
 
+
 rheSiteL :: Lens' (RunHandlerEnv child site) site
-rheSiteL = lens rheSite (\rhe new -> rhe { rheSite = new })
+rheSiteL = lens rheSite (\rhe new -> rhe {rheSite = new})
 {-# INLINE rheSiteL #-}
 
+
 instance MonadTracer (HandlerFor site) where
   getTracer = do
     tp <- getGlobalTracerProvider
     OpenTelemetry.Trace.Core.getTracer tp "hs-opentelemetry-instrumentation-yesod" tracerOptions
 
--- | Template Haskell to generate a function named routeToRendererFunction.
---
--- For a route like HomeR, this function returns "HomeR".
---
--- For routes with parents, this function returns e.g. "FooR.BarR.BazR".
+
+{- | Template Haskell to generate a function named routeToRendererFunction.
+
+ For a route like HomeR, this function returns "HomeR".
+
+ For routes with parents, this function returns e.g. "FooR.BarR.BazR".
+-}
 mkRouteToRenderer :: Name -> [ResourceTree a] -> Q [Dec]
 mkRouteToRenderer appName ress = do
   let fnName = mkName "routeToRenderer"
@@ -62,8 +71,10 @@
     , FunD fnName $ concat clauses
     ]
 
+
 goTree :: (Pat -> Pat) -> [String] -> ResourceTree a -> Q [Clause]
 goTree front names (ResourceLeaf res) = pure <$> goRes front names res
+#if MIN_VERSION_template_haskell(2, 18, 0)
 goTree front names (ResourceParent name _check pieces trees) =
   concat <$> mapM (goTree front' newNames) trees
   where
@@ -71,13 +82,21 @@
     toIgnore = length $ filter isDynamic pieces
     isDynamic Dynamic {} = True
     isDynamic Static {} = False
-#if MIN_VERSION_template_haskell(2, 18, 0)
     front' = front . ConP (mkName name) [] . ignored
+    newNames = names <> [name]
 #else
+goTree front names (ResourceParent name _check pieces trees) =
+  concat <$> mapM (goTree front' newNames) trees
+  where
+    ignored = (replicate toIgnore WildP ++) . pure
+    toIgnore = length $ filter isDynamic pieces
+    isDynamic Dynamic {} = True
+    isDynamic Static {} = False
     front' = front . ConP (mkName name) . ignored
-#endif
     newNames = names <> [name]
+#endif
 
+
 goRes :: (Pat -> Pat) -> [String] -> Resource a -> Q Clause
 goRes front names Resource {..} =
   pure $
@@ -88,7 +107,9 @@
   where
     toText s = VarE 'T.pack `AppE` LitE (StringL s)
 
+
 mkRouteToPattern :: Name -> [ResourceTree String] -> Q [Dec]
+#if MIN_VERSION_template_haskell(2, 18, 0)
 mkRouteToPattern appName ress = do
   let fnName = mkName "routeToPattern"
       t1 `arrow` t2 = ArrowT `AppT` t1 `AppT` t2
@@ -104,11 +125,33 @@
     toText s = VarE 'T.pack `AppE` LitE (StringL s)
     isDynamic Dynamic {} = True
     isDynamic Static {} = False
-#if MIN_VERSION_template_haskell(2, 18, 0)
     parentPieceWrapper (parentName, pieces) nestedPat = ConP (mkName parentName) [] $ mconcat
+      [ replicate (length $ filter isDynamic pieces) WildP
+      , [nestedPat]
+      ]
+    mkClause fr@FlatResource{..} = do
+      let clausePattern = foldr parentPieceWrapper (RecP (mkName frName) []) frParentPieces
+      pure $ Clause
+        [clausePattern]
+        (NormalB $ toText $ renderPattern fr)
+        []
 #else
+mkRouteToPattern appName ress = do
+  let fnName = mkName "routeToPattern"
+      t1 `arrow` t2 = ArrowT `AppT` t1 `AppT` t2
+
+  clauses <- mapM mkClause $ flatten ress
+
+  pure
+    [ SigD fnName ((ConT ''Route `AppT` ConT appName) `arrow` ConT ''Text)
+    , FunD fnName clauses
+    ]
+
+  where
+    toText s = VarE 'T.pack `AppE` LitE (StringL s)
+    isDynamic Dynamic {} = True
+    isDynamic Static {} = False
     parentPieceWrapper (parentName, pieces) nestedPat = ConP (mkName parentName) $ mconcat
-#endif
       [ replicate (length $ filter isDynamic pieces) WildP
       , [nestedPat]
       ]
@@ -118,21 +161,26 @@
         [clausePattern]
         (NormalB $ toText $ renderPattern fr)
         []
+#endif
 
+
 renderPattern :: FlatResource String -> String
-renderPattern FlatResource{..} = concat $ concat
-  [ if frCheck then [] else ["!"]
-  , case formattedParentPieces <> concatMap routePortionSection frPieces of
-      [] -> ["/"]
-      pieces -> pieces
-  , case frDispatch of
-      Methods{..} -> concat
-        [ case methodsMulti of
-            Nothing -> []
-            Just t -> ["/+", t]
-        ]
-      Subsite{} -> []
-  ]
+renderPattern FlatResource {..} =
+  concat $
+    concat
+      [ if frCheck then [] else ["!"]
+      , case formattedParentPieces <> concatMap routePortionSection frPieces of
+          [] -> ["/"]
+          pieces -> pieces
+      , case frDispatch of
+          Methods {..} ->
+            concat
+              [ case methodsMulti of
+                  Nothing -> []
+                  Just t -> ["/+", t]
+              ]
+          Subsite {} -> []
+      ]
   where
     routePortionSection :: Piece String -> [String]
     routePortionSection (Static t) = ["/", t]
@@ -144,43 +192,57 @@
       piece <- pieces
       routePortionSection piece
 
+
 data RouteRenderer site = RouteRenderer
   { nameRender :: Route site -> T.Text
   , pathRender :: Route site -> T.Text
   }
 
+
+-- TODO figure out a way to get better code locations for these spans.
+
+-- | This middleware works best when used with `OpenTelemetry.Instrumentation.Wai` middleware.
 openTelemetryYesodMiddleware
   :: (ToTypedContent res)
   => RouteRenderer site
   -> HandlerFor site res
   -> HandlerFor site res
 openTelemetryYesodMiddleware rr m = do
-  -- tracer <- OpenTelemetry.Trace.Monad.getTracer
   req <- waiRequest
-  mspan <- Context.lookupSpan <$> getContext
   mr <- getCurrentRoute
-  let sharedAttributes = catMaybes
-        [ do
-            r <- mr
-            pure ("http.route", toAttribute $ pathRender rr r)
-        , do
-            ff <- lookup "X-Forwarded-For" $ requestHeaders req
-            pure ("http.client_ip", toAttribute $ T.decodeUtf8 ff)
-        ]
-      args = defaultSpanArguments
-        { kind = maybe Server (const Internal) mspan
-        , attributes = sharedAttributes
-        }
-  mapM_ (`addAttributes` sharedAttributes) mspan
-  eResult <- inSpan' (maybe "yesod.handler.notFound" (\r -> "yesod.handler." <> nameRender rr r) mr) args $ \_s -> do
-    catch (Right <$> m) $ \e -> do
-      -- We want to mark the span as an error if it's an InternalError,
-      -- the other HCError values are 4xx status codes which don't
-      -- really count as a server error in OpenTelemetry spec parlance.
-      case e of
-        HCError (InternalError _) -> throwIO e
-        _ -> pure ()
-      pure (Left (e :: HandlerContents))
-  case eResult of
-    Left hc -> throwIO hc
-    Right normal -> pure normal
+  let mspan = requestContext req >>= Context.lookupSpan
+      sharedAttributes = H.fromList $
+        ("http.framework", toAttribute ("yesod" :: Text))
+          : catMaybes
+            [ do
+                r <- mr
+                pure ("http.route", toAttribute $ pathRender rr r)
+            , do
+                r <- mr
+                pure ("http.handler", toAttribute $ nameRender rr r)
+            , do
+                ff <- lookup "X-Forwarded-For" $ requestHeaders req
+                pure ("http.client_ip", toAttribute $ T.decodeUtf8 ff)
+            ]
+      args =
+        defaultSpanArguments
+          { kind = maybe Server (const Internal) mspan
+          , attributes = sharedAttributes
+          }
+  case mspan of
+    Nothing -> do
+      eResult <- inSpan' (maybe "notFound" (\r -> nameRender rr r) mr) args $ \_s -> do
+        catch (Right <$> m) $ \e -> do
+          -- We want to mark the span as an error if it's an InternalError,
+          -- the other HCError values are 4xx status codes which don't
+          -- really count as a server error in OpenTelemetry spec parlance.
+          case e of
+            HCError (InternalError _) -> throwIO e
+            _ -> pure ()
+          pure (Left (e :: HandlerContents))
+      case eResult of
+        Left hc -> throwIO hc
+        Right normal -> pure normal
+    Just waiSpan -> do
+      addAttributes waiSpan sharedAttributes
+      m
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -1,2 +1,3 @@
+
 main :: IO ()
 main = putStrLn "Test suite not yet implemented"