I mentioned this on a call earlier, but this is a pattern built on fsspec that I've found helpful.

https://github.com/TomAugspurger/era5/blob/main/src/stactools/era5/stac.py#L150-L155

The create_item includes the protocol and storage_options keywords.

def create_item(
    path: str,
    kind: str,
    protocol: str,
    storage_options: dict[str, Any] | None = None,
) -> pystac.Item:

And then the usage internally is

    storage_options = storage_options or {}
    fs = fsspec.filesystem(protocol, **storage_options)

And all paths are relative to the dataset root. All path-like operations within create_item would use fsspec. In theory, this lets you use the same code for STAC items that might live on different filesystems (S3, Azure Blob Storage, local, ...). Hope that's helpful :)