I know that standard deck construction involves attaching the beam on top of the post. On the small deck I am building (4X6) I would like to continue the posts up through to be the rail posts. Is there an acceptable metal bracket to make this possible?
You could attach the beams and posts using a lap joint where you cut away the thickness of the beam from the posts so that they can lock together. Similar to the picture, where the green board is the beam.
Then fasten them with a couple of lag bolts through the joint. That will provide a strong and durable joint.
You could cut a channel into the post to allow the beam to sit in it, this changes the load carrying capacity and it won’t slip over time.
The channel does not have to be too deep but sufficient that any warping won’t cause an issue.