Crooked real estate developer Jona Rechnitz, who once testified in scintillating detail about his pay-to-play relationship with Mayor Bill de Blasio, was sentenced Thursday to five months in prison and five months on house arrest.

Rechnitz faced up to two decades behind bars after pleading guilty in 2016 to honest services fraud. He has admitted to directing campaign donations to Mayor de Blasio in exchange for access to City Hall and showering NYPD leaders with prostitutes and other bribes to cultivate them as allies.

He'll serve only a fraction of the max sentence, thanks to his role as a star government witness in several recent high-profile trials. His explosive testimony helped to secure the convictions of former correction union chief Norman Seabrook, hedge fund founder Murray Huberfeld, and ex-friend and Orthodox power broker Jeremy Reichberg.

In their sentencing memo, federal prosecutors described Rechnitz as "one of the single most important and prolific white collar cooperating witnesses in the recent history of the Southern District of New York.”

"Throughout his cooperation, the information he has provided has been truthful, candid, and corroborated by other evidence," they continued.

During one trial, Rechnitz famously claimed that he spoke weekly with de Blasio on his personal cell phone, in exchange for contributions made to the mayor's barely legal nonprofit Campaign for One New York. In the lead-up to de Blasio's election, Rechnitz testified, the two would regularly discuss "different issues in the city, if he wins, who he should be appointing for certain positions. Just talking and getting to know one another. He took my calls. We were friends."

Asked about the testimony, the mayor called Rechnitz "a liar and a felon."

In addition to the short sentence, Rechnitz will also have to pay $10 million to the correction officers union, whose retirement funds he helped steer toward the corrupt hedge fund Platinum Partners, which later collapsed. Those payments will be due in $500,000 increments.

Reichnitz reportedly begged for mercy prior to the sentencing.

“My ego was big and I so badly wanted to impress these people,” he said. “I’ve been a real fraud to God."