The Commercial Paper (CP) market is essentially a private debt market used by corporations as a generally cheaper means of funding typical recurring operations than drawing on a line of bank credit.
Commercial paper, as financial instrument, is by no means a recent innovation and, in fact, you can read about how the CP market was affected by the many historic financial shocks experienced by the U.S. (read Panic on Wall Street: A History of America’s Financial Disasters)
Although the Federal Reserve was able to artificially bring CP rates down significantly since the shocking 615 basis point spread blowout (A2/P2 spread) of late 2008, they have apparently not been successful in preventing an overall contraction in the CP market.
The Federal Reserve calculates and published the total amount of CP outstanding every week and as of the latest published period, commercial paper outstanding is continuing to contract though a slow pace, registering just a 3.97% decline year-over-year.
It's important to note that at $1.091 trillion, total commercial paper outstanding is significantly lower than the level seen in the trough of the dot-com recession and very near the low for the series.