Does isaac-sim have Api to customize importing USD scene file?

I read the isaac sim documents, and found several python api in isaac sim doc
I see the URDF importer extension, but haven’t sawn any api about UDF importer. So my QUESTION is : does isaac sim provide the ability to customize the USD importing? Which means I can do some extra preparing job and then I can use call the function to import the USD scene file.
If it does, then could you provide any guide or doc link about the implementation ? Much thanks.

There are python apis for importing 3D assets to USD.

There is a sample here Basic Samples — Omniverse Robotics documentation

There is a snippet here as well

more documentation about importing assets:

Does this answer the question?

Thank you, I’ve seen these samples, but it seems these are about importing asserts from usd file. Maybe my question is not clear:
My purpose is that I want to interact with an encrypted usd file, which I can’t just directly load into isaac sim by clicking GUI buttons. That will surly fail, because Isaac sim can’t parse the customized file format.

Now I can write codes to decrypt it outside isaac-sim and then load it inside isaac-sim, but I think if I can put these work into isaac-sim plugin or extensions, it will be more secure and robust.

So I wonder is there a way to write some plugin or code to decrypt it and load it into the isaac -sim.

I see, yes you can write a custom extension. There is a hello world extension you can use as a template:

Extension docs:

You can also use the native python workflow to install your own pip packages and import other libraries.
So you can do any file decryption, write the file to a temporary location and then load the usd stage and continue.

thanks. These guides are helpful. will try to learn the steps to build an extension.

Trying to open the extension window, but then isaac-sim container crashed. Found the same issue in forum:

Is this problem fixed? I’m using version 2021.1.0