The NBA and National Basketball Players Association have reached agreement on a new seven-year collective bargaining agreement, promising labor peace through the rest of the decade, sources told ESPN early Saturday morning.

The tentative deal, which starts with the 2023-24 season, was announced by the league and union and is expected to be ratified by league governors and players in the coming weeks. The deal includes a mutual opt-out after the sixth year, sources told ESPN.

The agreement landed early Saturday morning after both sides agreed to extend a midnight ET deadline. NBA commissioner Adam Silver, NBPA executive director Tamika Tremaglio and negotiators on both sides -- including the NBA's Dan Rube and the union's Ron Klempner -- hammered out remaining details on the agreement, sources said.

After two extensions of the early opt-out deadline, the league's negotiations with Tremaglio and new NBPA president CJ McCollum delivered a deal months ahead of a possible work stoppage.

Among the key initial elements of the deal described to ESPN:

• The NBA is curbing the ability of the highest-spending teams, such as the Golden State Warriors and the LA Clippers, to continue running up salary and luxury tax spending while still maintaining mechanisms to add talent to the roster. The NBA is implementing a second salary cap apron -- $17.5 million over the tax line -- and those teams will no longer have access to the taxpayer mid-level in free agency. Those changes will be eased into the salary cap over a period of years.

Under these changes, Golden State's Donte DiVincenzo, Milwaukee's Joe Ingles, Boston's Danilo Gallinari and former Clippers guard John Wall wouldn't have been able to sign with those teams last summer.

As a counter to those spending limitations, the new CBA is expected to create more spending and trade opportunities for teams at the middle and lower spectrum of spending. There will be an opening of more opportunities in the free agent market, including larger trade exceptions.

• In an attempt to curb load management and lost games among star players, the NBA is tying eligibility for postseason awards -- such as All-NBA teams and MVP -- to a mandatory 65 games played. The 65-game minimum does come with some conditions.

• The in-season tournament could arrive as soon as the 2023-24 season. The event will include pool-play games baked into the regular-season schedule starting in November -- with eight teams advancing to a single-elimination tournament in December. The Final Four will be held at a neutral site, with Las Vegas prominent in the discussion, sources said.

Each in-season tournament game would count toward regular-season standings; the two finalists would ultimately play 83 regular-season games. Winning players and coaches will earn additional prize money.

• The NBA and NBPA have agreed to increase the upper limits on extensions from a 120% increase on a current deal to 140%, which could have a significant impact on the futures of stars like Celtics forward Jaylen Brown.

Under the current rules, Brown would be allowed to sign a four-year extension worth $165 million. With the extension rules increased to 140%, however, Brown -- who is set to earn $31.8 million in the 2023-24 season, the final year of his current contract -- would be able to reach his four-year maximum of $189 million, according to ESPN's Bobby Marks.

Similarly, Sacramento Kings All-Star center Domantas Sabonis could currently sign a four-year, $111 million extension -- one that jumps up to $121 million with the increase to 140%.

• There is an increase in two-way contract slots, jumping from two to three per team. Two-way contracts were created in the 2017 collective bargaining agreement as a vehicle for teams to develop younger players. It has been seen as a success, as it's become a route to players earning long-term homes in the league, and in several cases becoming major contributors.

Some of the biggest success stories to emerge from the two-way pipeline include: Austin Reaves and Alex Caruso with the Los Angeles Lakers; Duncan Robinson and Max Strus with the Miami Heat; Anthony Lamb with the Warriors; Jose Alvarado with the New Orleans Pelicans; and Luguentz Dort with the Oklahoma City Thunder.

ESPN's Tim Bontemps and Bobby Marks contributed to this report.