(CNN) Bipartisan congressional negotiators announced Monday night a deal over border security spending that, if signed, would prevent a government shutdown at the end of the week.

At issue had been how to fund the Department of Homeland Security -- most notably the fight over how to address President Donald Trump's signature campaign promise of a wall along the US border with Mexico.

Exact details were scarce in the initial moments following its announcement, but overnight, aides started to fill in at least some of the top line numbers expected to be included in the agreement. The final text of the legislation is expected to be posted by Wednesday, but in the meantime, here's what to expect:

Barrier funding

There is $1.375 billion for barrier funding that will cover roughly 55 miles of new barrier -- including parts of the Rio Grande Valley, which had been a priority for the White House.

The 55 miles is double the amount allocated in the last spending agreement, but 10 miles less than the bipartisan Senate Homeland Security funding bill from 2018 that Trump rejected.

The language and restrictions on the barrier itself are actually similar to what lawmakers have proposed in the past -- and had rejected by the President. The topline number also falls far short of the $5.7 billion requested by Trump in recent months.

Additionally, the deal prohibits the use of concrete walls and only "existing technologies" for border barriers that can be built. Bollard fencing is the most likely material to be used for any new barrier, aides say, but steel slats -- as Trump has previously proposed -- are technically also an option.

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