Why onnx_adapter is a differnt format from onnx?

[Cactice]

Are adapters not possible to express in a normal .onnx format?
I think if adapters were .onnx file we could use it with pure onnxruntime and check the internals with tools like netron.

However, onnx_adapter is not .onnx so in order to make use and understand the file the ecosystem is not very rich at the moment.
I wish it was xxx_adapter.onnx but I guess there's a reason why it has a different format.

[Cactice]

I guess adapters fundamentally overwrite some of the parameters on onnx model..
Sorry my general understanding on adapters might be too low