BUFFALO, N.Y. -- Josh Allen will be working with his favorite weapon for years to come, as the Buffalo Bills have reached agreement with wide receiver Stefon Diggs on a four-year, $104 million extension that includes $70 million guaranteed, sources told ESPN's Adam Schefter.

With two years remaining on his existing deal, Diggs' contract now runs through 2027 at a total value of $124.1 million. Both the Bills and Diggs would like him to retire in Buffalo, sources said.

The agreement follows a wave of top wide receiver deals this offseason, making Diggs' extension an inevitable conclusion for the Bills. New Miami Dolphins wide receiver Tyreek Hill received $72.2 million guaranteed, and Las Vegas Raiders wide receiver Davante Adams got $65 million guaranteed.

Allen's contract extension signed last year ties him to the Bills through the 2028 season.

The Bills acquired Diggs, 28, in a trade with the Minnesota Vikings in March 2020 in exchange for four draft picks, including a first-rounder. Since that trade, Diggs has put together two of the best seasons of his career, including his first two Pro Bowl appearances.

In his two years with the Bills, Diggs has caught 230 passes for 2,760 yards and 18 touchdowns. His 2020 season included career and league highs with 127 receptions, 1,535 receiving yards and eight touchdowns. In 2021, he caught a career-high 10 touchdowns during the NFL's first 17-game season.

Since his trade to the Bills, Diggs has ranked in the top 10 in the NFL in receptions, receiving yards and receiving touchdowns. The only players with more receptions than Diggs since the start of the 2020 season are Adams and Cooper Kupp, according to ESPN Stats & Information research.

Diggs' receptions and receiving yards are the first and fourth most by any player in their first two seasons with a team in NFL history, according to the Elias Sports Bureau. Diggs and Brandon Marshall (with the Chicago Bears) are the only players with 200 catches and 2,500 receiving yards in their first two seasons with a team all time.

"I want to give all players their respect and a fair pay, whoever it is, and Stef's no different," Bills general manager Brandon Beane recently said of Diggs. "... I think the world of Stef. I think what he's brought our team has been great. He's been great for Josh. He's been great for our offense, and his leadership has stepped up, and we want to see Stef in Buffalo for years to come."

The move is likely to create more money for the Bills to operate with this offseason. The team entered the week with less than $1 million in available cap space.

Selected by the Vikings in the fifth round of the 2015 NFL draft, Diggs spent the first five seasons of his career in Minnesota and signed a five-year extension with the team in 2018. His time with the Vikings did not end on the best of terms, and Diggs has been vocal about enjoying being in Buffalo and his connection on and off the field with Allen.