Contract Deployment

Contracts in Aztec are deployed as instances of a contract class. Deploying a new contract then requires first registering the class, if it has not been registered before, and then creating an instance that references the class. Both classes and instances are committed to in the nullifier tree in the global state, and are created via a call to a canonical class registry or instance deployer contract respectively.

📄️ Contract classes

A contract class is a collection of state variable declarations, and related unconstrained, private, and public functions. Contract classes don't have any initialized state, they just define code. A contract class cannot be called; only a contract instance can be called.

📄️ Contract instances

A contract instance is a concrete deployment of a contract class. A contract instance always references a contract class, which dictates what code it executes when called. A contract instance has state (both private and public), as well as an address that acts as its identifier. A contract instance can be called into.