I am trying to write a python script importer and the model contains vertex animations. I’ve gotten pretty far and searching the posts here I was able to get a TKinter interface to work but I am pretty new to both python and blender and Im still missing pieces of the puzzle. So far i have frame 0 imported correctly using NMesh (faces/vertex points/normals). I am unable however to add keyframes. I am guessing that should add the object once and then move the vertices/per frame. How do I go about changing the vertex coords for the mesh data/ per frame?? I seem to be missing something.
I was wondering if this should be done using bezier points and IPO curves but i dont know if you can manipulate each vertex of a mesh in this way in blender.
Any help would be appreciated 
Is there any way to add relative vertex keys through python?
It would seem to be that the way to do this would be by 1) creating a series of bezier curves from 0-1 at each frame which would control 2) a mesh deformation that was saved as a keyframe in the root ipo window. Im still playing with it but it seems that the former is possible using the ipo module but the later is not. I guess you could try to write a module which gives access the keyframe functions in blender?
p.s. i heard that this might be a feature of 2.28. Is that known?