Upgradeable Contracts
Introduction
Upgradeable smart contracts are designed to allow changes or improvements to a contract after it has been deployed to the blockchain. Normally, smart contracts are immutable, meaning their code cannot be modified once deployed. Upgradeable contract patterns attempt to introduce flexibility while still operating on a decentralized network.
This approach is often used when developers want to improve functionality, fix bugs, or add new features without requiring users to migrate to a completely new contract.
However, upgradeability introduces additional complexity and security considerations. Understanding how upgradeable contracts work helps users evaluate the level of control developers may retain over a system.
What is it
An upgradeable contract is a smart contract architecture that allows the logic of a contract to be updated while keeping the same contract address and stored data.
Instead of placing all logic directly in a single contract, upgradeable systems often separate components into:
Proxy contract – the contract users interact with
Implementation contract – the contract that contains the actual logic
Storage layer – the contract state that stores balances, ownership, or other data
When an upgrade occurs, the proxy contract is configured to point to a new implementation contract while keeping the existing storage intact.
This allows developers to update the system without requiring users to change the contract address they interact with.
How it works
Upgradeable contracts typically rely on proxy patterns that delegate execution to another contract.
A simplified process includes:
A proxy contract is deployed and becomes the main contract address users interact with.
The proxy forwards function calls to an implementation contract that contains the logic.
The implementation contract processes the request while the proxy stores the contract data.
If developers want to upgrade the system, they deploy a new implementation contract.
The proxy is updated to reference the new implementation.
Because the proxy contract keeps the original storage, user balances and state information remain unchanged after upgrades.
Several upgrade patterns exist, including proxy-based upgrade systems and controlled upgrade mechanisms.
Common risks
Upgradeable contracts can introduce additional risks compared to immutable contracts.
Common risks include:
Developers retaining upgrade permissions that allow changes to contract logic
Unauthorized upgrades if admin permissions are compromised
Upgrade errors that break compatibility with existing storage
Hidden functionality added through new implementations
Users not being aware that the contract can change behavior
For these reasons, upgradeable systems often include governance or permission controls to manage upgrades.
How to verify
Users can verify whether a contract is upgradeable by reviewing its structure and permissions.
Recommended verification steps:
Check if the contract uses a proxy architecture
Identify admin or upgrade functions within the contract code
Inspect ownership or governance permissions that control upgrades
Review documentation explaining how upgrades are performed
Monitor contract events that indicate upgrades or changes
Blockchain explorers may also display proxy relationships and implementation contracts.
Applied in ASTROC2M
Within the ASTROC2M ecosystem, transparency and contract verification help users understand how blockchain components operate.
Users can review smart contract structures and permissions through blockchain explorers, including features related to NFTs or other on-chain systems.
Encouraging users to verify contract behavior helps promote responsible interaction with Web3 technologies.