Glossary
This glossary defines the core terms used across Agglayer. Use it together with Architecture, Pessimistic Proof, Protobuf and gRPC, and Storage.
Aggchain proof
An optional proof payload attached to a certificate by a connected chain. Agglayer validates it according to the configured proof mode and commitment version.
Balance tree
A per-network Merkle structure that tracks token balances used by the pessimistic proof. State transitions in certificates update this tree. See Storage.
Bridge exit
A cross-chain transfer intent created on a source network. It is represented in Merkle commitments and consumed during verification and settlement.
Certificate
A chain update submitted to Agglayer. It carries the data needed to advance network state, including exit roots and optional proof material. See Architecture.
Certificate header
Metadata and status for a certificate stored by Agglayer. Headers track lifecycle state and failure information.
Commitment version
The schema version of the hash commitment signed or proven by a chain. Versions evolve over time (for example V2 through V5) to include additional fields and safety checks.
Epoch
A pacing window used by Agglayer to process and settle certificates. Epochs can be time-based or block-based depending on node configuration.
Imported bridge exit
A bridge exit originating from another network, included as an input to the destination network transition.
L1 info root
A root commitment from the L1 view used by Agglayer proof and validation logic. It anchors certificate processing to L1 context.
Local exit root
A Merkle root summarizing exits for a specific network transition. Certificates and proof outputs contain old/new local exit roots.
Network ID
The logical Agglayer identifier for a connected chain. Network ID is a key dimension for storage, rate limits, and lifecycle state.
Nullifier tree
A per-network Merkle structure used to prevent replay or double-consumption of bridge exits. See Storage.
Pessimistic proof
The core zero-knowledge proof used by Agglayer to verify state transitions safely. It is generated and verified through the SP1-based proof pipeline. See Pessimistic Proof.
Pessimistic root
A commitment in the pessimistic-proof state that summarizes balance/nullifier state. Proof outputs include previous and new pessimistic roots.
Proof mode
The verification mode configured for a network, for example legacy ECDSA, multisig, or STARK plus multisig. Mode selection determines which checks run for each certificate.
Settlement
The process of submitting a proven certificate result to Ethereum L1. Settlement finalizes cross-chain state transitions. See Architecture.
SP1 zkVM
The zero-knowledge virtual machine used by the pessimistic-proof program. Agglayer compiles the guest program to an ELF artifact and verifies proofs on host.
Verification key (vkey)
The cryptographic key identifying a specific proof program/circuit. A vkey change is security-sensitive and requires explicit acceptance workflow. See Pessimistic Proof.
Vkey selector
A short selector derived from the active verification key version, used by protocol components to route verification logic.
Witness
Concrete private and public input data fed into the proof program to produce a proof for a specific certificate transition.