Deep Dive
1. Jello Hardfork (December 2025)
Overview: This upgrade made Celo the first network to deploy OP Succinct Lite on mainnet, introducing zero-knowledge (ZK) fault proofs. For users, this means stronger security guarantees and more reliable monitoring of network operators.
The hardfork integrated ZK-powered fault proof infrastructure, which allows anyone to cryptographically challenge a sequencer's incorrect outputs. This moves Celo closer to a decentralized and trust-minimized rollup. Core user advantages like paying gas with stablecoins (fee abstraction) remained intact.
What this means: This is bullish for CELO because it significantly boosts the network's security and trustworthiness, making it more attractive for developers building serious applications. It addresses a key critique of optimistic rollups by adding cryptographic verification.
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2. Isthmus Hardfork (July 2025)
Overview: This was a scheduled mainnet upgrade that finalized Celo's technical alignment as an Ethereum Layer 2. It required node operators to update their clients, ensuring network-wide compatibility with new protocol features.
The hardfork processed at block height 31,056,500 on March 26, 2025, marking the definitive shift from a standalone L1. Exchanges like KuCoin and Upbit temporarily suspended deposits and withdrawals to support the seamless transition for user assets.
What this means: This is neutral for CELO as it represents the completion of a planned technical milestone rather than a new feature. It ensures the network's long-term viability and integration within the broader Ethereum ecosystem.
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3. CLI v7.0.0 Release (2025)
Overview: This major update to the celocli developer tool removed deprecated commands and optimized the codebase for the L2 era, making it faster and simpler for builders to interact with the network.
Key changes include purging L1-only validator commands, removing support for --gasCurrency config, and migrating core functions from Web3.js to the newer viem library. It also added an epoch:status command for better network insight.
What this means: This is bullish for CELO because a modern, efficient developer toolkit lowers the barrier for building new applications, which can drive ecosystem growth and utility. It signals active maintenance and a forward-looking technical roadmap.
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Conclusion
Celo's recent codebase trajectory prioritizes security upgrades, Ethereum alignment, and developer experience, cementing its technical foundation as a mobile-first L2. How will the integration of ZK fault proofs influence the next wave of applications built on the network?