> ## Documentation Index
> Fetch the complete documentation index at: https://docs.celo.org/llms.txt
> Use this file to discover all available pages before exploring further.

# L1 Fusaka Upgrade

## What is the Ethereum L1 Fusaka upgrade

The Fusaka hardfork contains various breaking changes on the L1. See [EIP-7607: Hardfork Meta - Fusaka](https://eips.ethereum.org/EIPS/eip-7607) for more info.

## Important dates

* Ethereum Sepolia Fusaka hard fork: Tuesday, October 14th, 2025 07:36:00 UTC, affects Celo Sepolia testnet.
* Ethereum Mainnet Fusaka hard fork: Expected early December 2025, affects Celo Mainnet. We will update this notice with the exact date, and new software releases, once it is confirmed

As Celo relies on Ethereum L1, node operators must make sure to provide a Fusaka compatible L1 node access for the Celo client.

<Note>
  For Celo users, there are no changes expected from the L1 Fusaka upgrade.
</Note>

## Call to Action

### For Node Operators

#### L1 Ethereum clients

You need to make sure that your L1 nodes are updated to a compatible version. Check the [Ethereum Client release list](https://blog.ethereum.org/2025/09/26/fusaka-testnet-announcement#client-releases) for compatible versions.

#### L2 Celo client

There are no upgrades required for the Celo L2 client for the L1 Fusaka upgrade. We recommend the latest released versions:

* `op-geth` at [v2.1.2](https://github.com/celo-org/op-geth/releases/tag/celo-v2.1.2)
* `op-node` at [v2.1.0](https://github.com/celo-org/optimism/releases/tag/celo-v2.1.0)
* `eigenda-proxy` at [v1.8.2](https://github.com/layr-labs/eigenda/pkgs/container/eigenda-proxy/437919973?tag=v1.8.2)

## Getting Help

Please reach out to our team on [Discord](https://chat.celo.org) in the [#celo-L2-support](https://discord.com/channels/600834479145353243/1286649605798367252) channel if you have any questions.