Dear Celo Community,
As part of ongoing alignment with the broader OP Stack ecosystem, Celo will be transitioning from op-geth to op-reth as the supported execution client for the network.
Following Optimism’s deprecation of op-geth, Celo will also discontinue support for op-geth and adopt op-reth as the primary execution client moving forward.
Migration Timeline
The transition will occur in two phases:
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Celo Sepolia (testnet): June 24, 2026
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Celo Mainnet: Approximately four weeks later, pending final readiness and ecosystem coordination
Additional details, including exact mainnet timing, will be shared closer to the upgrade.
What Is Changing?
op-geth
op-geth will remain supported until late July. After that point, it will no longer be compatible with the network and nodes running op-geth will fall out of sync.
op-reth
op-reth will become the supported execution client for Celo. Built on the Reth execution layer, op-reth offers improved performance and is the long-term execution client supported by the OP Stack ecosystem.
op-node
No changes are required for op-node. It continues to be fully supported.
Required Action for Node Operators
All node operators must migrate from op-geth to op-reth before the mainnet upgrade.
A Celo-compatible op-reth release, updated deployment tooling, and migration documentation will be made available prior to the Celo Sepolia upgrade. We encourage operators to begin reviewing op-reth and planning their migration timelines now.
Additional updates will be shared through:
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The Celo Forum
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The celo-l2-node-docker-compose repository
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Celo developer documentation
RPC Providers and Infrastructure Partners
For most RPC consumers, this transition should be seamless. op-reth supports the same standard JSON-RPC interface as op-geth.
Infrastructure providers, bridge operators, indexers, and other advanced integrations should validate their systems against op-reth during the testnet phase, particularly if they rely on non-standard, tracing, or debug RPC methods. More details will be provided in the documentation.
Why This Change?
The transition ensures continued compatibility with future Ethereum and OP Stack upgrades, including the upcoming Glamsterdam hardfork. Migrating to op-reth also aligns Celo with the execution client roadmap adopted across the broader OP Stack ecosystem.
We encourage all node operators, infrastructure providers, and ecosystem partners to participate in testing on Celo Sepolia beginning June 24 and to prepare for the subsequent mainnet migration.
Further technical documentation and migration guidance will be shared shortly.
Thank you for helping ensure a smooth transition for the Celo ecosystem.
Celo Core Co.