Invariants and Assertions

Invariants and assertions are specific programming practices used to define and enforce the expected state of a contract at all times. An invariant is a condition that must always be true, such as the requirement that the total amount of tokens in a liquidity pool must always equal the sum of individual user balances.

An assertion is a statement within the code that checks if a condition is met; if it is not, the transaction is automatically reverted. These tools act as a continuous, internal security guard that prevents the protocol from entering an unstable state.

During an audit, the team identifies the key invariants of the protocol and ensures that the code contains the necessary assertions to protect them. By embedding these checks directly into the smart contract, developers can create a self-defending system that catches and stops potential exploits in real-time.