Validators are permissioned actors responsible for signing checkpoints on an Outbox, facilitating message transmission to remote chains.
Membership in the validator set is determined by a proof-of-stake protocol implemented as a set of smart contracts on each Abacus-supported chain.
Validators can retrieve the most recent checkpoint by calling Outbox.latestCheckpoint(). After a checkpoint has achieved sufficient finality, validators are expected to sign it and store their signature on highly available storage so that their signatures can be relayed to one or more Inboxes.
/**
* @notice Returns the latest checkpoint for the Validators to sign.
* @return root Latest checkpointed root
* @return index Latest checkpointed index
*/
function latestCheckpoint()
external
view
returns (bytes32 root, uint256 index);Validators that sign anything other than a finalized checkpoint risk compromising the safety of the protocol, and may be slashed.
Abacus Works is developing the validator as a Rust binary that can be easily run by anyone. Operationally, validators need to run this binary and a node for the chain that they are validating for. We hope that the majority of Abacus validators will come from each chain's existing node operator community.