GIven a route[] that might be called either directly from the request route (transaction does not exist) or asynchronously (transaction exists), a way is needed to rationally choose between sl_send_reply and t_reply.
At the moment, I am using an intermediate async route and setting $var(async) = 1 and then testing that when a reply needs to be sent. It seems there could be a more elegant solution.
One thought I had is a new tm function that will choose between t_reply and sl_send_reply depending on whether a transaction has been created.
Any other ideas? Or am I missing an obvious solution?