> ## 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 the Ethereum L1 Fusaka hardfork means for Celo node operators

## 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

Fusaka activated on Ethereum Mainnet on Wednesday, December 3rd, 2025 at 21:49:11 UTC and on Ethereum Sepolia on Tuesday, October 14th, 2025 at 07:36:00 UTC; it affected Celo Mainnet and Celo Sepolia respectively.

As Celo relies on Ethereum L1, node operators had to provide Fusaka-compatible L1 node access for the Celo client.

> [!NOTE]
>
> The Fusaka upgrade required no changes for Celo users.

## Call to Action

### For Node Operators

#### L1 Ethereum clients

L1 nodes had to be updated to a Fusaka-compatible version before the fork. The [Ethereum client release list](https://blog.ethereum.org/2025/09/26/fusaka-testnet-announcement#client-releases) names the compatible versions.

#### L2 Celo client

No upgrade of the Celo L2 client was required for the L1 Fusaka upgrade. The Celo client versions recommended at the time were `op-geth` [v2.1.2](https://github.com/celo-org/op-geth/releases/tag/celo-v2.1.2), `op-node` [v2.1.0](https://github.com/celo-org/optimism/releases/tag/celo-v2.1.0) and `eigenda-proxy` [v1.8.2](https://github.com/layr-labs/eigenda/pkgs/container/eigenda-proxy/437919973?tag=v1.8.2). For current versions see [Network config](/operate/operators/network-config).

## Getting help

Ask in [#celo-L2-support](https://discord.com/channels/600834479145353243/1286649605798367252) on [Discord](https://chat.celo.org) if you have any questions.


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