The Gang of Eight consists of the Speaker of the House, the House Minority Leader, the Senate Majority Leader, the Senate Minority Leader, and the chairs and ranking members of the House and Senate Intelligence Committees.
Under the National Security Act of 1947 and the Intelligence Authorization Act of 1980, the president is required to keep the Gang of Eight "fully and currently informed" of covert activities. The executive branch sometimes limits the full intelligence committee to just the Gang of Eight for the most sensitive operations, making this group the core of congressional intelligence oversight.