The main issue was here. Not every response contains a status key as it depends on the implementation of the streaming callback functions.

A fallback case is also added. In this fix, I'm not trying to come up with a general solution but just one that works for the patterns I saw. The tests use callbacks that return values in the patterns I was already working with.

I guess you could just match on the presence of the status:

case meta.result do
  {:ok, %{status: status}} when is_integer(status) -> status
  {:ok, {_request, %{status: status}}} when is_integer(status) -> status
  {:ok, {status, _headers, _body}} when is_integer(status) -> status
  _ -> 0
end

Because there is a risk that even when response is a map, response.status may not be set. As far as I can tell that part of the event is the stream accumulator and it could be anything, any term.

(edit fixed my clauses 😅 )