The Corporate Sector Authority, or CSA was the governing authority of the Corporate Sector.
Prior to the Age of the Empire, the Corporate Sector was made up of a series of loosely-aligned autonomous star systems, independent from the Galactic Republic, which were home to numerous corporations as well as tax evaders, arms merchants, and pirates. By 18 BBY, these star systems were considered to be slowly coalescing into a unified entity, which was one of the main reasons the Galactic Empire decided to send a message to the systems defying it by occupying the Salient system on the edge of the sector. Despite this, these systems would eventually coalesce to create the Corporate Sector Authority.
Thirty years after the Battle of Endor, the Resistance leader General Leia Organa received intelligence that the CSA was giving monetary support to the First Order who was channeling large sums of money to the New Republic Senator Erudo Ro-Kiintor's accounts through shells and third-party corporations via the CSA. Ro-Kiintor had indirectly supported the First Order by delaying or derailing motions in the Galactic Senate calling for sanctions against the First Order and increasing support for the Republic Navy. Using this information, Leia sent the Resistance starfighter pilot Poe Dameron on a mission to steal Ro-Kiintor's starship Hevurion Grace.