Celo has completed three independent smart contract audits with Web3 security firm Hashlock, covering its Staked smart contracts, Optimism smart contracts, and CeloSuperchainConfig. All three engagements, completed in October 2025, February 2026, and March 2026, received a “Secure” rating.
What Is Celo?
Celo is an Ethereum-anchored Layer 2 built 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, which gives the network a practical advantage for real-world financial activity.
The network averages one-second block times, gas fees around $0.0005, and has grown to more than 250,000 daily active users. Celo is designed for payments, stablecoins, and practical onchain use cases, with a strong focus on accessible financial infrastructure.
What Was Audited
The three Hashlock engagements covered Celo’s Staked smart contracts, Optimism smart contracts, and, most recently, CeloSuperchainConfig. That latest contract handles pause state logic, guardian controls, and upstream configuration propagation across the Superchain. Hashlock reviewed it through manual line-by-line analysis, supported by automated testing.
The March 2026 report found that the contract achieves its intended functionality, follows clear and well-ordered logic, and relies on widely trusted dependencies including OpenZeppelin. One gas optimization item and one QA item were identified and resolved. The codebase was also noted as well commented and closely aligned with NatSpec best practices.
Why It Matters
For a network processing real payments at scale, contract security is foundational. Weaknesses in bridge-adjacent logic, configuration controls, or staking contracts can affect far more than a single application and may impact broader ecosystem reliability. Independent audits help identify those risks before they become costly problems.
The fact that multiple layers of Celo’s stack have now been reviewed and rated Secure across a series of engagements gives builders and users a stronger basis for trust. It also reinforces Celo’s position as infrastructure built for dependable financial activity onchain.
Ongoing Security Commitment
Celo’s work with Hashlock is not a one-time exercise. With multiple completed engagements and additional reviews planned, the ongoing collaboration reflects a long-term commitment to securing the protocol as Celo continues to scale its payments and stablecoin infrastructure.
Resources
Celo’s full audit listings 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 firm specializing in smart contract auditing and blockchain cybersecurity. Hashlock has conducted 200+ audits and helped secure over $1.3 billion in onchain value across DeFi, gaming, infrastructure, and enterprise blockchain systems.
Website: https://hashlock.com/
About Celo
Celo is an Ethereum-anchored Layer 2 focused on payments, stablecoins, and DeFi. Its public materials describe a modular architecture that combines OP-Stack infrastructure, EigenDA, zkEVM-based verified execution, ERC-20 gas payments, and a payments-first design built around one-block finality, sub-cent fees, and carbon-aware transaction infrastructure.
Website: https://celo.org/
X: https://x.com/Celo
