What is Smart Contract Audit?
A smart contract audit is a professional security review of smart contract code to identify vulnerabilities, logic errors, and potential exploits before deployment — the primary security assurance mechanism in DeFi.
WHY IT MATTERS
Audits are DeFi's substitute for regulation. Before a protocol handles real money, independent security firms review the code: checking for reentrancy, overflow, access control issues, economic attacks, and logic errors.
Major audit firms include Trail of Bits, OpenZeppelin, Certora (formal verification), Spearbit, and Code4rena (competitive audits). Each has different methodologies and specializations.
Important caveat: an audit is not a guarantee. Audits are point-in-time reviews that may miss novel attack vectors. Audited protocols have been exploited. Audits reduce risk — they don't eliminate it.