Gary Wang, co-founder and former CTO of failed crypto exchange FTX, is assisting the federal government in developing software tools to detect financial fraud and illicit activities on crypto exchanges, according to a court document filed ahead of his November 20 sentencing.

“Gary has worked with the government to design and build a new software tool to detect potential financial fraud in public markets,” Wang’s lawyers wrote in a Wednesday court filing.

They added that the FTX co-founder is “developing a separate tool focused on identifying illicit activity on crypto exchanges.”

Wang, who struck a plea deal with the Department of Justice in December 2022, served as a key witness in the trial of former FTX CEO Sam Bankman-Fried. Bankman-Fried has appealed his conviction.

During the trial, Wang’s testimony was crucial in establishing that Bankman-Fried was aware of a back door through which Alameda Research, his crypto hedge fund, illegally accessed FTX customer assets.

Wang is scheduled to appear before US District Court Judge Lewis Kaplan for sentencing, where his legal team has requested no prison time, citing his cooperation with law enforcement among other factors.