Blender script to convert active attribute to a shape key

active_attribute_to_shape_key.py

import bpy

# convert the activ attribute to a shape key
# the active attribute is expected to be a Vector in the Vertex domain
def active_attribute_to_shape_key(context):
    obj = context.active_object
    mesh = obj.data
    attribute_index = mesh.attributes.active_index
    attribute = mesh.attributes[attribute_index]
    
    # if there are no shape keys, add the Basis Shape Key
    if not mesh.shape_keys:
        sk_basis = obj.shape_key_add(name="Basis")
        sk_basis.interpolation = 'KEY_LINEAR'
    
    # add shape key with the name of the selected attribute
    sk_attribute = obj.shape_key_add(name=attribute.name)
    sk_attribute.interpolation = 'KEY_LINEAR'
    # assign the values from the attribute to the shape key
    for i in range(len(mesh.vertices)):
        sk_attribute.data[i].co = attribute.data[i].vector        
    
active_attribute_to_shape_key(bpy.context)