Soft Finality

Soft finality describes a state where a transaction is accepted by the rollup nodes and considered likely to be included in the final canonical chain, but it has not yet reached full settlement on the base layer. Users often receive immediate feedback that their transaction is processed, allowing for faster application responsiveness.

However, this state is subject to reorganization or reversal if the sequencer is malicious or if the rollup experiences a deep chain split. Soft finality is essentially a promise of inclusion based on the current sequence of transactions.

It is widely used in decentralized exchanges to provide a seamless user experience that mimics centralized systems. While useful for speed, it lacks the absolute security guarantees of hard finality, which only occurs after the fraud proof window passes.