The `127 Hours` star has sold the book `Actors Anonymous`, which is said to be loosely on his life, to online retailer Amazon, eschewing the normal publishing route.
Although the tome is his debut novel, it is not his first book - he previously released a collection of short stories entitled `Palo Alto`.
The new deal was brokered by his literary agent Richard Abate of 3 Arts.
James is well renowned for his love of changing his work constantly, in addition to his acting career, he also hosted the Academy Awards in 2010 with Anne Hathaway - amid much criticism - and in November announced he was planning to shoot and direct a fashion campaign for Seven For All Mankind.
He has also previously made an amateur sex tape, although he was not happy with the results.
He said: "When I was young, it`s not like I went down to Van Nuys and tried to break into the porn industry, I got a video camera and my girlfriend and I decided to film ourselves. And we watched it back and said, `Yeah, let`s never watch that again.` "