Action Confirmation Status

The framework provides four distinct levels of confirmation or finality for each user-initiated action, each successive level increments in time to completion but concurrently enhances the security guarantee. This granularity provides developers the opportunity to craft user experiences around throughput-security trade-offs.

C0 : Acknowledged (instant)

The rollup operator generates and returns a signature on the user action. This signature serves as a formal acknowledgment denoting the successful reception of the user action and serves as a rudimentary mechanism for censorship resistance, particularly important considering the central hosting of micro-rollups.

C1 : Executed (milliseconds)

The application undertakes the execution of the user action, thereby affecting a change in the application’s internal state. This confirmation guarantees that the executed action is incorporated into a block.

C2 : Verified (seconds to minutes)

The third level of confirmation involves the transmission of the block to the verification layer, which, pessimistically re-executes the state transition for correctness, thus cementing the assurance that the application has properly executed the state transitions.

C3 : Finalized (minutes to hours)

The verification layer posts a commitment to this data, either as raw state data or ZKPs, on-chain and provides a guarantee that the batch has successfully traversed to the L1 layer

Stackr splits C3 even further between DA and L1

• C3a: DA Finality (seconds to a minute)

This confirmation level involves the posting of the action batch data as a blob to a data availability layer. This ensures that the data can be trustlessly retrieved to derive the rollup’s state.

• C3b: L1 Finality (minutes to hours)

The verification layer posts a commitment to the action batch data on-chain to verify and guarantee that the batch has been appended to the rollup’s canonical chain and is impervious to subsequent tampering or alterations