When doing your chart, if you click on the "extended chart selection" option and scroll down to the bottom of the page, you will see a box on the left hand side of the page. In that box (amongst many other asteroids) is the Vertex.

Also, the Vertex is not a transiting body. It is only a point in your natal chart (just like your ascendant, descendant, midheaven and I.C), and the moving planets make transits to that natal point.

If the vertex is at 29 degrees is it considered critical also?

double post, merc rectch

@ Daisy - YMMV, but I only give emphasis to physical bodies and not points at critical/anaretic degrees.

Squares, conjunctions, and oppositions to the Vertex (and Anti-Vertex) via transit can be important. I've also found this to be the case with trines and even the inconjunct if these transits hit the Vetex from both sides, say in the case of a pseudo Grand Trine or Yod. I don't read hypothetical or mathematical points as part of major aspect patterns, but if you have transits hitting the Vertex from both sides like this it tends to show IMO. Again, YMMV.

@ VFT - It might be an interesting exercise for you to reflect back upon the dates of significant encounters in your life and run your transits to see what was up with your Vetex during those times. When you meet someone under a transit to your Vetex it is often something that shifts the direction of your life markedly.