Let us say that James Vacca is not necessarily the first person you’d think would begin a deeply necessary revolution to peel away some of the secrecy around technology that shapes government decisions. In the 1980s, Mr. Vacca admitted, he told an aide that it would be a waste of money to replace office typewriters with word processors.

Yet on Thursday, Mr. Vacca, 62, a Democratic City Council member from the Bronx, introduced a bill that would require the city to make public the computer instructions that are used, invisibly, in all kinds of government decision-making. Experts say that few, if any, major cities in the United States require transparency for those computer instructions, or algorithms.

If the principles in Mr. Vacca’s bill become law, it could turn out be as important to public society in the city and around the country as the smoking ban signed into law by Mayor Michael R. Bloomberg in 2002.

“I think I’m on to something that many people have spoken about, but have been unable to get their hands around,” Mr. Vacca, chairman of the council’s technology committee, said. “I’m trying to get my hands around something that affects millions of New Yorkers every day.”