Celo has completed three independent smart contract audits with Web3 security company Hashlock, covering its Staked smart contracts, Optimism smart contracts and CeloSuperchainConfig. The three missions, completed in October 2025, February 2026 and March 2026, received a “secure” rating.
What is Celo?
Celo is a layer 2 anchored in Ethereum, designed for payments, stablecoins and DeFi. Its architecture runs on the OP stack, uses EigenDA for data availability, and supports zkEVM-based verified execution via Succinct SP1. Users can pay gas fees in stablecoins such as USDT, USDC, and cUSD, giving the network a practical advantage for real-world financial activity.
The network lasts an average of one second, gas fees are around $0.0005, and now has over 250,000 daily active users. Celo is designed for payments, stablecoins, and practical on-chain use cases, with a strong focus on accessible financial infrastructure.
What was audited
The three Hashlock commitments covered Celo’s Staked smart contracts, Optimism smart contracts, and most recently CeloSuperchainConfig. This latter contract manages pause state logic, gatekeeper controls, and upstream configuration propagation across the Superchain. Hashlock reviewed it via manual line-by-line analysis, supported by automated testing.
The March 2026 report reveals that the contract achieves intended functionality, follows clear and well-ordered logic, and relies on widely trusted dependencies, including OpenZeppelin. A gas optimization item and a quality assurance item were identified and resolved. The codebase was also noted as being well commented and closely aligned with NatSpec best practices.
Why it matters
For a network processing real-world payments at scale, contract security is fundamental. Weaknesses in bridge-adjacent logic, configuration controls, or staking contracts can affect more than a single application and impact the reliability of a broader ecosystem. Independent audits help identify these risks before they become costly problems.
The fact that multiple layers of Celo’s stack have now been reviewed and rated secure through a series of engagements gives builders and users a stronger foundation of confidence. This also strengthens Celo’s position as an infrastructure built for trusted on-chain financial activity.
Ongoing Safety Commitment
Celo’s work with Hashlock is not a one-off exercise. With several engagements completed and additional reviews planned, the ongoing collaboration reflects a long-term commitment to securing the protocol as Celo continues to evolve its payments and stablecoin infrastructure.
Resources
Complete Celo audit lists are available on Hashlock’s Celo audit page. The latest report covering CeloSuperchainConfig.sol is publicly available. More information about Celo’s architecture and design is available at celo.org.
About Hashlock
Hashlock is a leading Web3 security company specializing in smart contract auditing and blockchain cybersecurity. Hashlock led More than 200 audits and helped to secure over $1.3 billion in on-chain value in DeFi, gaming, infrastructure and enterprise blockchain systems.
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About Celo
Celo is a layer 2 anchored on Ethereum and focused on payments, stablecoins and DeFi. Its public documents outline a modular architecture that combines OP-Stack infrastructure, EigenDA, zkEVM-based verified execution, ERC-20 gas payments, and a payments-first design built around block finality, sub-cent fees, and carbon-sensitive transaction infrastructure.
Website: https://celo.org/
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