Definition
A proxy contract is an on-chain system component that delegates execution of its calls to one or more separate implementation contracts, typically via low-level forwarding opcodes. It usually holds the authoritative state and address used by external callers, while the underlying logic resides elsewhere. This indirection enables logic replacement or modularization without changing the proxy’s address or migrating its stored data.
In Simple Terms
A proxy contract is a smart contract that mainly forwards calls to another contract where the real logic lives. The proxy keeps the same address and stores the data, while the separate implementation contract can be changed or reorganized. This setup lets developers adjust contract logic without moving the users or the stored information.
Context and Usage
Proxy contracts are primarily discussed in the context of EVM-based systems, upgradeable contract patterns, and security reviews. They appear in standards and libraries that separate storage from logic, as well as in architectures that rely on indirection for modular design. Audits of proxy setups often focus on storage layout consistency, delegatecall behavior, and potential attack surfaces such as misconfigured access control or reentrancy-sensitive forwarding.