6:08pm: The team has officially announced the signing via press release.
"James Harden is the foundational-type player we have been looking to add," owner Leslie Alexander said. "He is a tremendous, young player with the ability and skill set to be an All-Star. He is ready to make the next move up to join the elite players in the NBA. As I said when we traded for James, he along with the mix of young players we already have in place, such as Jeremy Lin, Chandler Parsons and Omer Asik, gives us a solid group of young, talented players who will help get us back to a championship level."
2:10pm: James Harden has agreed to a five-year contract extension with the Rockets, according to Adrian Wojnarowski of Yahoo! Sports (via Twitter). Wojnarowski initially pegs the value of the extension at $80MM, though he adds in a second tweet that it's a maximum-salary deal, meaning the exact figures aren't yet set in stone.
Harden was, of course, acquired by the Rockets over the weekend, at which point it was reported that the two sides would reach an agreement on a five-year, maximum-salary contract. The Thunder, having already designated Russell Westbrook as their franchise player, could only offer Harden a four-year extension, and were said to be offering less than the maximum salary — something in the neighborhood of $53MM for four years.
With Harden under contract through 2018, the Rockets figure to build around a core that includes Jeremy Lin, Omer Asik, and the reigning Sixth Man of the Year. Those three players' salaries will amount to a cap hit of more than $30MM in 2013/14. However, the rest of the Rockets' team salary will be made up of rookie contracts or non-guaranteed deals, which should give them the cap space to be a major player in free agency.
As for Harden's new deal, the exact amount of the 2013/14 maximum salary for a player with his experience isn't yet known, but it will likely increase at least a little. Westbrook's five-year, max-salary extension, which uses 2012/13's figures, will pay him about $78.6MM, so Harden's deal is expected to exceed that.