The numbers are stunning.

On Sunday, more than 59,200 people slept in New York City shelters, including 23,433 children. As the shelters fill up, thousands of people who are homeless are housed in motels. Beyond that, NYC is trying to develop more permanent shelter space, too, but community members are quick to protest, as they did this weekend in Maspeth, where the city wants to convert a Holiday Inn Express into a shelter for more than 200 adults.

But it’s the long-term solutions, such as supportive housing, that should be treated with as much urgency. The units include mental health, drug treatment, and other services. Mayor Bill de Blasio pledged 15,000 such units in November. Earlier this year, Gov. Andrew M. Cuomo promised 20,000 more. He committed to spend about $2 billion on affordable housing, including $1 billion for 6,000 supportive housing units, over five years.

Those promises have yet to become a reality. Cuomo’s commitment was dependent on Albany legislative leaders agreeing on the terms of the plan. Instead, Cuomo, Assembly Speaker Carl Heastie and Senate Majority Leader John Flanagan agreed only to an initial one-year payout — $150 million for 1,200 supportive units statewide.

There are few details, and no money has been allocated long-term. State officials say a specific plan is coming. Others suggest lawmakers are tying supportive housing promises and funds to whether they can come to an agreement on renewing the now-expired 421a tax subsidy.

But there are too many unknowns. An effort of this size and scope won’t succeed with that uncertainty.

NYC officials say they’re moving forward on plans for new supportive housing units and scattered sites in existing buildings. They should provide detailed updates, too.

It makes sense for Cuomo to dole out state funds annually to make sure deadlines and benchmarks are met. But there has to be a long-term agreement by all three leaders, with a timetable, location breakdowns and funding guarantees. That’s the only way to hold everyone accountable, and change the lives of those who are homeless.