Dear Celo Community,
Introduction & Recap of Alfajores L2 Testnet Launch
The launch of Alfajores L2 Testnet has been a collaborative effort with many of our key partners, and we’re thrilled to see several teams already upgrading to work seamlessly with the L2 environment. Partners like Blockscout, Thirdweb, Celoscan, Celo Terminal, and Infura have all made strides to ensure they are fully operational on Alfajores L2. If you have not upgraded yet, now is the time to do it.
Since the launch of the L2 testnet, we’ve made several important updates based on early feedback. Two minor documentation issues were quickly identified and resolved, helping to clarify some initial confusion. Additionally, three non-critical bugs were reported and fixed, improving the overall user experience—thank you to everyone who flagged these! We are also in the process of discovering various RPC methods that need to be enabled for Forno users, ensuring more robust functionality. We’ve identified some inconsistencies in how Celo operates compared to other OP stack-based L2s and are actively working to address these for smoother interoperability. Lastly, the migration of Valora to Alfajores L2 has been successful, marking a positive step toward broader ecosystem adoption. Overall, the community response has been very positive, and developer engagement is ramping up. Keep the feedback coming!
Code Audit Announcement
As we continue building towards Layer 2, the code audit is the next big step to ensure the network is secure, reliable, and trustworthy for all users. We’re excited to share that as of last week, work on the Celo L2 codebase has wrapped up and we have entered the audit phase of the L2 rollout. The audit will span several weeks, during which the code will be thoroughly reviewed. After the audit is complete, we will enter a review period to address any findings and implement necessary fixes. Once everything is finalized, we’ll share the audit results with the community to maintain full transparency.
We’ve chosen to collaborate with Trail of Bits, a highly respected auditing firm with a proven track record in blockchain security. Their team has previously worked with Celo, Optimism, and other leading projects in the space, making them well-versed in the unique challenges of Layer 2 solutions. Trail of Bits is familiar with key aspects of our system, including the use of stablecoins as gas currency, our blockchain client, and the OP stack, ensuring that the audit will be conducted with the highest level of scrutiny and expertise.
A major focus of the audit is on the changes that we have made to op-geth and the optimism repo to maintain backwards compatibility with the existing Celo network. These include our gas payable by tokens functionality, which will be preserved after the hard fork. Additionally, we have ported over the pre-compile that allows us to “pre-wrap” CELO tokens so they can be accessed via the ERC20 interface as before.
Another key aspect related to backwards compatibility, is auditing the migration of the Celo PoS elections code from a hybrid model (blockchain client + smart contracts) to being entirely smart contract-based. This shift aids Celo in becoming more Ethereum compatible, as it removes the need to have logic in the client (protocol); and keeps all logic in smart contracts. This is great for 3rd party tooling, as it has been a pain point for many integrations in the past.
The audit will also explore new functionality that was introduced as part of the upgrade. This includes the new 1 second block time and the introduction of the EigenLayer enabled alt-da (alternative data availability). With the upgrade, CELO is also transitioning to becoming an Ethereum-based token, and it is crucial that we roll out the change with a proper implementation of Optimism’s custom gas token feature, which is still in an experimental phase. Unlike before, the client will not have the flexibility to mint CELO freely (e.g. for staking rewards) after the L2 transition. To address this, the entire total supply of CELO will be pre-minted on Layer 1 and locked in the bridge, gradually releasing supply to the L2 on a set schedule that mirrors the current minting mechanism on Celo. This approach replaces the existing system of minting small portions of CELO daily, ensuring continuity while offering increased levels of security maintained by Ethereum. The auditors will need to thoroughly assess this concept to confirm that it operates safely and effectively.
cLabs follows a Secure Software Development Lifecycle which includes a Smart Contract Security Audit, a critical step in mitigating vulnerabilities when integrating different systems. This is especially important as we leverage emerging technology from Optimism. We need to ensure that these innovative features are safe for production use. Conducting this audit aims to build trust and share this confidence with both Celo’s users and developers.
Following the audit, we have some exciting milestones on the horizon. Our next steps will include the migration of the Baklava testnet and, eventually, mainnet.
Conclusion
In summary, the launch of the Alfajores L2 Testnet marks an important step forward, and we’re excited by the early engagement and positive feedback from the community. Our partners have made great progress in upgrading their services to run smoothly on L2, and we look forward to seeing more teams join them. With the code audit now underway, we’re focused on ensuring the security and reliability of our network, especially as we incorporate innovative features from Optimism. This audit will help strengthen the platform and build trust among developers and users. We’ll keep the community informed throughout the process. Your involvement and feedback remain key to our journey, and we’re eager for the future of Celo’s Layer 2.
The cLabs team
Congrats on the successful launch of Alfajores L2 Testnet and the great progress made so far! 
It’s exciting to see key partners onboard and early feedback being addressed so quickly. 
The focus on security with Trail of Bits and the ongoing audit 
shows strong commitment to the network’s reliability. Looking forward to the next steps! 