I know I'm conscious, but I cannot assume that you are conscious, perhaps you are just a stochastic parrot?
The only reasonable solution is to assume that anything that passes a true, well executed Turing test is conscious
The only reasonable solution is to assume that anything that passes a true, well executed Turing test is conscious
As far as writing messages alone, that could be software.
Like so many fixed things in life, "consciousness" seems to be a frontier, not a demarcation.
For instance, if you're having a lucid dream, are you conscious or unconscious?