A basic webhook function. It validates a request with a channel secret, and parses the request into a list of webhook events.

To handle failures, the result is in the form of ExceptT WebhookFailure.

A webhook handler for WAI. It uses webhook internally and returns a WAI Application.

An example webhook server using WAI will be like below:

app :: Application
app req f = case pathInfo req of
  "webhook" : _ -> do
    secret <- getChannelSecret
    webhookApp secret handler defaultOnFailure req f
  _ -> undefined

handler :: [Event] -> IO WebhookResult
handler events = forM_ events handleEvent $> Ok

handleEvent :: Event -> IO ()
handleEvent (MessageEvent event) = undefined -- handle a message event
handleEvent _ = return ()

A basic error handler to be used with webhookApp. It returns 400 Bad Request with the WebhookFailure code for its body.