As Celo transitions from an independent L1 to an Ethereum L2, it is important to clarify which Celo Improvement Proposals (CIPs) have been executed, removed, or modified during this migration. Below is a breakdown of the CIPs that were integrated, those that were deprecated, and the broader implications of these changes.
CIPs Successfully Migrated to L2
These CIPs have been implemented in the new environment or were already part of the protocol before migration:
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Validator-Run Attestation Service (CIP-1) – Attestation service, previously removed.
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Identity Claims and Metadata (CIP-3)
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General Account Signer Authorization (CIP-10)
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Multi Currency Support (CIP-33) – Contracts, including cEUR support.
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Granda Mento (CIP-38) – Contracts.
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Extension to ODIS for Password Hashing (CIP-40) – Contracts.
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Block Context Fixes (CIP-43) – Fixed gas price and allowlist-related issues.
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Modify Transaction Fee Check (CIP-45) – Addressed a previous incorrect comparison.
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Gas Repricing for Celo (CIP-48) – Aligned gas costs with upstream Ethereum.
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Optional Replay Protection (CIP-50) – Already supported in op-geth.
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Federated Attestations Protocol (CIP-51) – Attestation-related.
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Ultragreen Celo (CIP-52) – A portion base transaction fees go to the Carbon Offsetting Fund.
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Removal of Obsolete Features (CIPs 53-57) – Includes removing minimum client version check, Tobin tax, freezable epoch rewards, and full node incentives.
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Ethereum Compatibility Updates (CIPs 58-61) – Adjustments to opcode gas costs, BaseFee, and block headers to align with Ethereum.
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New Transaction Type: Celo Dynamic Fee v2 (CIP-64)
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Gingerbread Hardfork (CIP-62) – Integrated CIPs (52-65)
CIPs That Were Removed in the Migration
These CIPs were explicitly removed, either because they were obsolete without a validator set, replaced, or unnecessary in the Ethereum L2 environment:
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Governance & Hotfixing (CIP-4) – Replaced with a Security Council approach.
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Direct Announce & Validator Discovery (CIP-5) – No longer needed.
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Governable Lookback Window (CIP-21) – Not used by the client anymore.
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Upgrade Epoch SNARK Data (CIP-22) – SNARK data removed.
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Obsolete Hardforks (CIPs 24, 27, 41) – Features from Churrito, Donut, and Espresso hardforks are already in op-geth.
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Ethereum Transaction Compatibility (CIP-35) – CeloLegacyTx deprecated.
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Modification to EIP-1559 (CIP-42) – Aligned BaseFeePerGas with op-geth, deprecated certain transaction types.
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Round Change Timeout Formula Modification (CIP-47) – No longer needed due to consensus changes.
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Total Transaction Data Limit (CIP-65) – Ethereum is taking a different approach to the same problem in the upcoming Pectra hardfork. In the interest of staying aligned with Ethereum’s direction, we’re opting to follow their lead rather than reinstating CIP-65 in its current form.
As we transition to an L2 architecture, we’re excited to continue aligning more closely with Ethereum—both in terms of protocol design and community standards. One area this alignment touches is gas pricing. With the introduction of EIP-1559, we’re adopting a more predictable and Ethereum-native model for base fee management.
As part of this shift, the base fee floor (formerly referred to as “Minimum Gas Price” on L1) will no longer be a governable parameter in the traditional sense. This change helps us stay in sync with the upstream op-geth codebase, reducing technical debt and streamlining future upgrades. It also simplifies our governance surface while keeping us compatible with Ethereum’s broader ecosystem.
This parameter is now set via hardfork, allowing us to reduce custom client logic and remain aligned with both Ethereum and the op-geth stack. While Optimism has explored making all the upstream EIP-1559 parameters configurable through their SystemConfig contract, this would require contract-level changes that we may revisit in the future—either through collaboration or further development.
Overall, this is another step toward Ethereum-aligned scalability, with simpler governance and a more unified protocol experience.
Conclusion:
The transition to Ethereum L2 is a defining moment for Celo, and we appreciate the community’s engagement in shaping this next chapter. If you have insights or feedback on these changes, we encourage you to participate in the discussion!
The cLabs Team
