There it is.
The complete library for the MCP2221A. I2c adapter, I/O in a single IC. I love that one.
Let me know if any bug is found.
I try to make that library as much convenient as possible to use. Two version available 32 bit and 64 bit. little note: to open by serial number, the enumeration need to be activated on the device first. (open by index, enable the enumeration) It needs to be done only once in the life time of the device.
PLEASE do not take ownership of this work since it is not yours. You have it for free, but the credit is still mine... I spent many hours of my life to make it works.