diff --git a/ms-azure-api.cabal b/ms-azure-api.cabal
--- a/ms-azure-api.cabal
+++ b/ms-azure-api.cabal
@@ -1,5 +1,5 @@
 name:                ms-azure-api
-version:             0.6.0.0
+version:             0.6.0.1
 synopsis:            Microsoft Azure API
 description:         Bindings to the Microsoft Azure API
 homepage:            https://github.com/unfoldml/ms-graph-api
diff --git a/src/MSAzureAPI/BotService.hs b/src/MSAzureAPI/BotService.hs
--- a/src/MSAzureAPI/BotService.hs
+++ b/src/MSAzureAPI/BotService.hs
@@ -1,3 +1,4 @@
+{-# options_ghc -Wno-unused-imports #-}
 -- | Azure Bot Framework
 --
 -- https://learn.microsoft.com/en-us/azure/bot-service/rest-api/bot-framework-rest-connector-quickstart?view=azure-bot-service-4.0
@@ -15,7 +16,7 @@
   , TextBlock(..)
   , ColumnSet(..)
   , Column(..)
-                             ) where
+  ) where
 
 import Data.Char (toLower)
 import GHC.Exts (IsString(..))
@@ -31,7 +32,7 @@
 -- text
 import Data.Text (Text, pack, unpack)
 
-import MSAzureAPI.Internal.Common (run, APIPlane(..), Location(..), locationDisplayName, (==:), get, getBs, post, postRaw, getLbs, put, tryReq, aesonOptions)
+import MSAzureAPI.Internal.Common (run, APIPlane(..), Location(..), locationDisplayName, (==:), get, getBs, post, postRaw, getLbs, put, tryReq, aesonOptions, say)
 
 
 -- * Send and receive messages with the Bot Framework : https://learn.microsoft.com/en-us/azure/bot-service/rest-api/bot-framework-rest-connector-send-and-receive-messages?view=azure-bot-service-4.0
@@ -45,7 +46,8 @@
           -> AccessToken -> Req ()
 sendReply acti txt atts atok =
   case aReplyToId acti of
-    Nothing -> pure ()
+    Nothing -> do
+      say "sendReply: replyToId is null"
     Just aid -> postRaw urib ["v3", "conversations", cid, "activities", aid] mempty actO atok
       where
         urib = aServiceUrl acti
@@ -68,9 +70,9 @@
 --
 -- https://learn.microsoft.com/en-us/azure/bot-service/rest-api/bot-framework-rest-connector-send-and-receive-messages?view=azure-bot-service-4.0#send-a-non-reply-message
 sendMessage :: (A.FromJSON b) =>
-               Text
-            -> Text
-            -> Activity
+               Text -- ^ base URI, taken from the @serviceUrl@ property in the incoming 'Activity' object
+            -> Text -- ^ conversation ID
+            -> Activity -- ^ message payload
             -> AccessToken -> Req b
 sendMessage urib cid =
   postRaw urib ["v3", "conversations", cid, "activities"] mempty
@@ -83,12 +85,12 @@
   , aId :: Maybe Text
   , aChannelId :: Maybe Text
   , aConversation :: ConversationAccount
-  , aFrom :: ChannelAccount
-  , aRecipient :: ChannelAccount
+  , aFrom :: ChannelAccount -- ^ sender
+  , aRecipient :: ChannelAccount -- ^ recipient
   , aServiceUrl :: Text -- ^ URL that specifies the channel's service endpoint. Set by the channel.
   , aReplyToId :: Maybe Text
-  , aText :: Text
-  , aAttachments :: [Attachment]
+  , aText :: Text -- ^ message text
+  , aAttachments :: [Attachment] -- ^ message attachments
                          } deriving (Show, Generic)
 instance A.FromJSON Activity where
   parseJSON = A.genericParseJSON (aesonOptions "a")
diff --git a/src/MSAzureAPI/Internal/Common.hs b/src/MSAzureAPI/Internal/Common.hs
--- a/src/MSAzureAPI/Internal/Common.hs
+++ b/src/MSAzureAPI/Internal/Common.hs
@@ -34,6 +34,8 @@
   , locationDisplayName
   -- ** JSON co\/dec
   , aesonOptions
+  -- ** misc
+  , say
   ) where
 
 import Control.Monad.IO.Class (MonadIO(..))
@@ -293,3 +295,6 @@
 -- > dropPrefix "Mr. " "Dr. Men" == "Dr. Men"
 dropPrefix :: Eq a => [a] -> [a] -> [a]
 dropPrefix a b = fromMaybe b $ stripPrefix a b
+
+say :: MonadIO m => String -> m ()
+say = liftIO . putStrLn