get the position of a specific vertex in an After Effects shape
As of 2019 you can access a path of a shape or a mask like so:

myShape = thisComp.layer("Shape Layer 1").content("Shape 1").content("Path 1").path;


The path property is an object containing collections of points, inTangents and outTangents. It has three methods for obtaining the vertex details, points() returns the vertices, and inTangents() and outTangents() return the tangent handle positions if they have any. Each method optionally takes a time parameter to specify what time the data is retrieved. e.g.:

myPoints = myShape.points(); //you can optionally specify the time, e.g. .point(t=123)
myPoints[0]

myInTangents = myShape.inTangents();
myInTangents[0]


In addition there are other methods for getting an arbitrary point on a path not at a vertex, and for finding out if the path is closed. It's a world of fun! Read the docs here