Hey Celo Community,
Quick update on the op-geth to op-reth transition we announced earlier: the testnet phase is done, and it went well.
Celo Sepolia switched to op-reth on June 24 as planned, and it has been humming along ever since. Blocks are flowing, nodes are syncing, and nothing caught fire. A big thank you to everyone who migrated early and helped us validate the new client.
With testnet behind us, we can now lock in the final date:
Celo Mainnet moves to op-reth on July 22, 2026.
What Node Operators Need to Do
If you run a mainnet node, migrate to op-reth before July 22. op-geth will not support the L1 Glamsterdam hardfork, and nodes still running op-geth at activation will not be able to follow the canonical chain.The Celo-compatible op-reth release is out, and the docs are updated. Start with the End of Support for op-geth notice, which has the release and full instructions. The short version:
- Follow Run a node with Docker to get op-reth running.
- Your old op-geth datadir will not carry over. op-reth uses a different on-disk format, so start it with an empty
DATADIR_PATHand bootstrap from a published snapshot (OP_RETH__SNAPSHOT=true, required on mainnet). No L1 data migration needed. - Running an archive node or need L2 historical data? See Running an archive node.
- The Configuration reference covers the
OP_RETH_\_\*variables, and the latest images live in celo-l2-node-docker-compose. - Check https://snapshots.celo.org/ for available snapshots and more information regarding snapshots.
- Prefer to build the image yourself? Build from the celo/reth-v1.0.0 release.
op-node itself remains fully supported, but we recommend adding or updating these flags on your op-node(s) when pairing it with op-reth:
\--l2.enginekind=reth\--syncmode=execution-layer
One friendly nudge: you can migrate today. Bootstrapping from a snapshot is quick (expect roughly 1 to 3 hours, depending on your config), so we recommend starting as soon as possible to be ready ahead of the switch on July 22.
RPC Providers and Infrastructure Partners
For most RPC consumers, this should be a non-event. op-reth speaks the same standard JSON-RPC as op-geth.
If you run a bridge, indexer, or anything that leans on non-standard, tracing, or debug RPC methods, test against op-reth on Celo Sepolia now. It has been running the new client for two weeks, so it is the perfect place to shake out any differences before mainnet.
Where to Follow Along
- The Celo Forum
- The celo-l2-node-docker-compose repository
- Celo developer documentation
Thanks again to everyone who made the testnet migration smooth. One more switch to go.
The Engineering Team-Celo Core Co.