Tuong,
The I/Q recorder in Spike is not open source. That being said, we could look into extracting some useful code from the recorder as an example for customers to use. I will consider what this would look like.
We have a much older open source recording utility that was written for the BB60A/C many years ago. It illustrates multi-threaded recording of full IF/IQ data. It will likely not compile against our current APIs, but it might be helpful for you.
https://relatedcontentdemo.kinsta.cloud/sigdownloads/BB60C/BB60_Demos.zip
Andrew