Much of New York City's financial data will be available in a newly searchable, machine-readable, programmatically accessible form through a new web application, New York City Comptroller John C. Liu was scheduled to announce this morning.

Liu was scheduled to pull the curtain off Checkbook NYC 2.0, a revamped version of existing software that previously listed city spending. Liu announced last year that he would be investing in a new suite to greatly enhance the information available to the public and to make it easier to understand by adding data visualizations and better navigation.

The new site was modeled after USASpending.gov and built by REI Systems, the same company that built the federal spending data portal. It draws information on spending and contracts directly from the city's accounting software and presents it to the user through a mix of graphs and charts.

For transparency advocates, the site itself won't be as important as the precedents it sets. Every set of summary data displayed with a chart on the front page comes with detailed data beneath it, all of which available through a bulk data download or via API. Spending information is available by agency or payee. Modifications to contracts are displayed as well as contracts themselves, meaning users can track changes as city projects' budgets inflate. And the site already aggregates various financial reports produced by the city, including some that even many city officials didn't know existed. The entire project should be open source within two to three months, officials at the comptroller's office told me, meaning the entire project should be anyone's to adapt or improve upon.

Officials promise that data on budget and revenues will be coming to the site soon, meaning that visitors should be able to match spending — and city income — against expectations.

The site has other room for improvement. Last year, Deputy Comptroller for Public Affairs Ari Hoffnung told me it was expected to cost $1.5 million. The price tag at launch will be about $2.1 million, and it may cost $3 million by the time the project is complete. But none of this shows up in Checkbook NYC 2.0 at the level of this project because it is a subcontract, and the application currently does not list subcontracts. Similarly, the same principals are sometimes behind multiple companies. This means that although company that garnered a fine or citation on a previous project isn't the one applying for a subsequent contract, the same principals might benefit. The city Mayor's Office of Contract Services has data on these types of relationships but limits the amount of information available to the public.

Subcontracting data and the relationships between prime contractors and subcontractors are planned additions to the site, officials say.

Although city payroll is public information, names are left off of Checkbook NYC 2.0 — payroll is arranged by department, title, and salary. So while a Checkbook user might be able to see what type of city employee is clocking the most overtime, that user won't be able to find that person by name — at least not on the Internet.

And the site's data visualizations and charts are just a polished top layer to what remains a labyrinthine and hard-to-understand world of municipal finance. For instance, spending breakdowns follow city units of appropriation. How these units are structured is arcane knowledge possessed by a learned few. The site might see internal as well as external use — it might be useful, for example, for officials with stronger policy minds than chops with accounting software — but it does nothing to make the bureaucracy of document IDs and unit codes easier to understand. Similarly, because vendors form special joint ventures or other single-use entities in order to bid for city business, public access to information about vendors is not as useful for accountability as it would be if it also tracked the relationships between vendors. An uninitiated user won't know that right away.

Officials will announce today that the comptroller, independently elected so as to be a check on the mayor by design, has raised the bar for municipal transparency — but they'll also admit that bar could go a lot higher, and maybe it will.