Polkadot will transition from the slot bidding mechanism to the Agile Coretime mechanism through Proposal #1143.

Odaily Planet Daily News According to Proposal #1143, the Polkadot community will transition from the previous slot auction mechanism to the Agile Coretime mechanism. It is reported that Agile Coretime is a new parachain resource allocation mechanism. Unlike slot auctions, it can simplify the allocation process, improve flexibility, and eliminate the high cost and uncertainty of auction models by allowing projects to lease network computing resources (i.e. Coretime) through sales. In addition, in the latest proposal #1161, the community has voted to approve the detailed plan for the Coretime sale, including setting the initial price and sales parameters. (PolkaWorld)