The bipartisan group negotiating to avoid another shutdown announced on Monday night that it had the broad outlines of a border security agreement to do so.

The top Democrats and Republicans on the House and Senate appropriations committees came out of a long Monday evening meeting to say they think they’ve reached a deal “in principle” to fully fund the government, which is set to run out of funds on Friday at midnight.

But they declined to discuss any details of the agreement, which would fully fund the government through the fall. Whatever the group has agreed upon still needs to pass both chambers of Congress — and win over President Trump, who is the big question mark in the equation.

“We reached an agreement in principle between us on all the homeland security and the other six bills,” Senate Appropriations Committee Chairman Richard Shelby (R-AL) told reporters Monday night as he emerged from a meeting with Sen. Patrick Leahy (D-VT) and their House counterparts, Reps. Nita Lowey (D-NY) and Kay Granger (R-TX).

The details of the deal itself appear to still be in flux. A source briefed on the deal told TPM that the rough agreement cuts the number of detention beds available to the Immigrations and Customs Enforcement agency for undocumented immigrants, a point demanded by Democrats, and adds some money for new physical barriers at the border to please Republicans. According to the Washington Post, the deal cuts the total number of detention beds from 49,000 to 40,500, and gives $1.375 billion for border barrier construction — short of the $5.7 billion Trump has previously demanded.

Trump didn’t signal whether he’d accept the deal.

“Maybe progress has been made, maybe not,” he said during a Monday night rally.

And conservative commentators including Fox News’s Sean Hannity attacked the agreement, an ominous sign for negotiators.

Negotiators have bounced back and forth about whether they thought they had a deal in recent days. The lawmakers had made happy sounds about getting a deal late last week before saying Sunday that an agreement had fallen apart. They’d been at odds over the number of detention beds available, as well as exact figures for some new border fencing.

To prevent another shutdown, lawmakers need to reach a full agreement almost immediately in order to get the legislation passed and signed before the weekend — though, if they need a few more days, a temporary and technical shutdown over the weekend wouldn’t have much of a real-life impact.

This story was last updated at 10:15 p.m.