Terminology

Shared vocabulary used across the book and the codebase. See the Glossary for the alphabetical index.

Runtime

• PXE — Private Execution Environment. The client-side runtime that executes private functions, decrypts notes, and produces client proofs.
• Embedded PXE — the in-process PXE runtime shipped as aztec-pxe.
• Node — an Aztec network node that serves public state, block data, and accepts transactions via JSON-RPC.

Transactions

• Private function — a function executed inside the PXE; inputs and outputs remain encrypted on-chain.
• Public function — a function executed by the sequencer against public state.
• Utility function — an off-chain helper exposed by a contract artifact; does not mutate state.
• Entrypoint — the account contract function used to authenticate and dispatch a user’s transaction.
• Authwit — an authorization witness granting one account permission to act on behalf of another.

State

• Note — a unit of encrypted private state owned by an account.
• Nullifier — a value that marks a note as spent.
• Contract instance — a deployed contract identified by an address and class.
• Contract class — an artifact registered on-chain by its class identifier.

Cross-Chain

• L1 message — an Ethereum-originated message delivered to L2.
• L2-to-L1 message — an L2-originated message for consumption on Ethereum.
• Portal — the L1 contract that anchors a cross-chain pair.

Fees

• Fee Juice — the asset used to pay fees on Aztec.
• FPC — Fee Payment Contract; a contract that sponsors fees for a user.