A tentative agreement reached between UNO Charter School Network administration and staffers at 3 a.m. Wednesday morning — technically three hours after a strike deadline passed — still depends on finding $1.5 million the charter operator doesn’t have yet.

UCSN schools opened Wednesday morning for its 8,000 students, who came within hours of bearing witness to the first charter school strike in the country. That’s despite the funding gap as well as “some small details” still being worked out on Thursday, as the United Educators of UNO described them.

On the final day of negotiations — which were joined by Randi Weingarten, president of the national American Federation of Teachers — management and the teachers reported being “very close,” but still $1.5 million short.

“After much discussion, we all agreed that the most important thing is to keep schools open while we investigate ways to bridge that gap,” UCSN CEO Richard Rodriguez told reporters.

He said that UCSN will ask Chicago Public Schools for help in identifying additional sources of revenue to fill the gap that represents less than 2 percent of UCSN’s budget.

That’ll include determining whether a portion of $88 million in tax-increment financing just released to Chicago Public Schools “will be shared with all public schools, including charters,” Rodriguez said, adding that the charter chain also will “look for ways to reduce costs and operate as efficiently as possible across the organization.”

CPS could not immediately be reached for comment.

“We think our rank and file will be satisfied with this agreement, it’s certainly a vast improvement over what management was originally prepared to offer,” UEU spokeswoman Christine Geovanis said.

The union will return to the bargaining table on Thursday “to work out some small details” and will then have something to present to their membership for review, Geovanis said.

Citing budget cuts from CPS, which reduced per-pupil funding since last year, management had sought concessions from the teachers and staff, asking them to pay more for their pensions and health care.

UCSN agreed to keep in place a 7 percent pension contribution for current employees, but just like CPS’ tentative agreement with its teachers union, that contribution will cease for new hires, who instead will get a 7 percent raise. Teachers and support staff also will see a summer break slightly longer than their current five weeks, according to the union.

And non-teaching staff will get a 3 percent raise in both years of the contract, if it’s ratified by the union, then approved by the school’s board of directors, a UCSN spokesman said.

And the parties will form a joint committee to make financial recommendations when funding falls short at UCSN.

Negotiations started well more than six months ago, according to the UEU. Its 525-plus members had voted overwhelmingly to authorize the strike.