> import qualified Web.Slack as Slack

> import qualified Web.Slack.Api as Api

> import Control.Monad.Reader

> :set -XOverloadedStrings

> slackConfig <- Slack.mkSlackConfig token

> flip runReaderT slackConfig (Slack.apiTest Api.mkTestReq)
Right ...

> flip runReaderT slackConfig (Slack.apiTest Api.mkTestReq { Api.testReqFoo = Just "bar" })
Right ...