The cornerstone’s contract extension is etched in stone. Adam Fox, the kid from Jericho who grew up wanting to play for the Rangers and then effected two trades from two NHL organizations in order to fulfill his manifest destiny, is going to be tangled up in Blue for a long, long time.

Credit the Rangers and general manager Chris Drury for getting this done at a fair price and in a timely manner. Credit Fox and his agent, Matt Keator, for not squeezing the Rangers and the GM on the length of the deal by committing to seven years — rather than five — for an annual cap hit of $9.5 million per that kicks in next season.

Yes, it is a pricey deal, the most expensive per year ever given out to one of the Blueshirts’ own and the most expensive ever given to a defenseman coming out of an entry-level contract. But then, if the Rangers have ever had a defenseman like Fox, you have to go back to Brian Leetch to find one, and then before that, Brad Park. We are talking about Royal Blue here.

True enough, the 23-year-old has played only 134 NHL games. But that has provided enough of a sample size to determine that he is an elite athlete with uncommon skills and a ceiling that is virtually unlimited. In this ecosystem in which teams long ago ceded their leverage regarding second contracts, paying top dollar to an elite player such as Fox is an essential price of doing business.

Drury recognized this. You cannot go wrong paying players like Fox, not that there are very many of them at all. So much of this business of signing free agents to long-term deals involves risk. In this case, Fox is the reward.

The Rangers long have rewarded players for their exploits on other teams, signing marquee free agents to eye-opening deals while routinely forcing their own restricted free agents to grind for every dollar. That established a landscape on which few were ever willing to take less to stay because few were ever willing to take less to come. This is a trend that is coming to an end.

The Rangers have defined their core that will be in place through at least 2024-25, after which Igor Shesterkin will be eligible to become an unrestricted free agent. Drury signed the goaltender this summer for a club-friendly cap hit of $5,666,667 for a four-year term that benefits the Russian. Fox is in through 2028-29, Mika Zibanejad through 2029-30, Chris Kreider and Barclay Goodrow through 2026-27, Jacob Trouba and Artemi Panarin in through 2025-26.

Those seven players will account for a combined $53,451,191 of cap space. Add Kaapo Kakko, due for a new deal after this season, and Alexis Lafreniere, who has two years to go on entry level, and that is the group around which the Rangers will succeed or fail. Drury is likely looking at a scenario where he will have around $21 million over the next few years to fill in the rest of the roster that will include adding a second-line center and a backup goaltender.

Could the Rangers be vulnerable to an offer sheet on Kakko this summer? Only if the Finn wants out the way his fellow countryman Jesperi Kotkaniemi wanted out of Montreal last year. If Kakko is unsigned when the market opens in July, then maybe he will troll for an offer sheet Drury probably would be unable to match. But the Rangers surely will do what they can to sign Kakko before then. The same scenario would exist a year later for Lafreniere. If they want out, they’re probably gone. But the issue then wouldn’t be about the cap, it would be about why they’d want to leave after three years?

With space extremely tight for the foreseeable future, the Rangers will have to hit it big on support players like Sammy Blais at $1.9 million (who is a restricted free agent after the season) and get substantial contributions from players on entry-level deals. This, by the way, is another reason it would be so helpful if there were a reconciliation between the hierarchy and Vitali Kravtsov. This represents another reason why Morgan Barron’s growth is important.

Patrik Nemeth, for example, has been just fine thus far but it is difficult to imagine the team being able to afford a veteran third-pair defenseman at $2.5 million next season. That roster spot is going to have to go to Zac Jones or Matt Robertson or, if someone switches sides, to Braden Schneider. The Blueshirts will need Will Cuylle or Brennan Othmann to arrive ahead of schedule. There is going to be little margin for error with the bottom cap line so stressed.

The bottom line this day, though, is that the Rangers have their man at a fair price. The homeboy is staying home for a long, long time.