Crucial update: following the original issuance of this article, Lodestar has released a new version, v1.15.0, which Holesky participants are required to upgrade to before Dencun’s launch on February 7th. Moreover, both Prysm and Nimbus have issued highly recommended updates for Holesky. Prysm users are advised to switch to v4.2.1, while Nimbus users should upgrade to v24.2.0.
- Goerli blobs are now available: Dencun was activated on Goerli at 6:32 UTC on January 17, 2024. You can now access blobs there!
- Sepolia and Holesky will undergo upgrades in the upcoming two weeks. Dencun will be activated on Sepolia at epoch 132608 (January 30th, 22:51 UTC), and on Holesky at epoch 29696 (February 7th, 11:35 UTC).
- Client updates in this notice are appropriate for both testnet upgrades.
- Provided that the Sepolia and Holesky upgrades proceed without issues, Dencun will subsequently be planned for the Ethereum mainnet.
- To receive email notifications about network upgrade announcements, including the Dencun mainnet upgrade, subscribe here.
The Dencun network upgrade has been successfully activated on the Goerli testnet as of January 17, 2024. It is now set for the remaining two testnets, Sepolia and Holesky, at the following times:
The upgrade comprises several modifications, particularly the introduction of temporary data blobs with EIP-4844, commonly referred to as “protodanksharding”, which aims to lower L2 transaction expenses.
Dencun follows last year’s Shapella upgrade. It will first roll out to Ethereum testnets. Once these networks are operating smoothly with the upgrade, Dencun will be arranged for deployment on the Ethereum mainnet.
Upgrade Specification
The Dencun upgrade amalgamates modifications to both Ethereum’s consensus and execution layers. A comprehensive list of protocol amendments can be located in EIP-7569. For your reference, they include:
Deneb
Complete python specifications for modifications affecting Ethereum’s consensus layer can be accessed in the deneb folder of the ethereum/consensus-specs repository.
Cancun
The EIPs mentioned above detail the full specifications for modifications affecting Ethereum’s execution layer.
Furthermore, a python specification for these changes is being implemented in the ethereum/execution-specs repository.
Lastly, Deneb necessitates modifications to the Engine API, utilized for communication between the consensus and execution layer nodes. These are detailed in the cancun.md file of the ethereum/execution-apis repository.
Client Releases
The subsequent client releases are compatible with Dencun on both Sepolia and Holesky. Future versions will enable support on the mainnet. Once these become available, another notification will be issued on this blog.
When selecting which client to operate, validators should remain particularly aware of the dangers of using a majority client on either the execution layer (EL) or consensus layer (CL). An explanation of these risks and their implications can be found here. An approximation of the current EL and CL client distribution along with guidelines for switching between clients can be located here.
Consensus Layer Sepolia & Holesky Releases
Notes:
- Holesky Lodestar v1.15.0-rc.0 users must upgrade to v1.15.0.
- Holesky Nimbus v24.1.2 users are strongly urged to update to v24.2.0.
- Holesky Prysm v4.2.1-rc.1 users are strongly urged to move to v4.2.1.
- When operating a validator, both the Consensus Layer Beacon Node and Validator Client need to be updated.
Execution Layer Sepolia & Holesky Releases
Note: while Reth supports Dencun, the client is still awaiting a complete audit and is not recommended for production deployment. Please refer to the Reth README for further information.
FAQ
As an Ethereum user or Etherholder, is there anything I need to do?
In summary, no.
If you utilize an exchange, digital wallet, or hardware wallet, you are not required to take any action unless directed to do so by your exchange or wallet provider.
If you operate your own Ethereum node, please refer to the following question.
As a non-staking Sepolia or Holesky node operator, what actions should I take?
To ensure compatibility with the upgrade on either testnet, upgrade your node’s execution and consensus layer clients to the versions specified in the table above.
As a Sepolia or Holesky staker, what actions should I take?
To maintain compatibility with the upgrade on either testnet, please update your node’s execution and consensus layer clients to the versions indicated in the table above. Ensure that both your beacon node and validator client are updated.
As a non-Sepolia or Holesky node operator or staker, what steps should I take?
Nothing for the moment. Additional announcements will be provided regarding Dencun’s activation on the mainnet. You can subscribe to receive email notifications for them here.
Stakers wishing to navigate the upgrade process multiple times before mainnet are encouraged to utilize ephemery.dev, which now accommodates Dencun.
What occurs if I am a Sepolia or Holesky staker or node operator and do not engage in the upgrade?
If you are using an Ethereum client that hasn’t been updated to the latest version (as listed above), your client will synchronize with the pre-fork blockchain once the upgrade is implemented.
You will be caught on an incompatible chain adhering to the old rules, preventing you from sending Ether or functioning on the post-Dencun Ethereum network.
As a developer of applications or tooling, what should I do?
Examine the EIPs included in Dencun to ascertain how they may impact your project — numerous exciting new features are being introduced across both the execution and consensus layers! The only EIPs with implications for backwards compatibility are EIP-6780, EIP-7044 and EIP-7514.
Why is it called “Dencun”?
Upgrades to the consensus layer utilize star names, while those for the execution layer follow the names of Devcon cities. “Dencun” combines Deneb, a first-magnitude star within the Cygnus constellation, and Cancun, the site of Devcon 3.
Original cover image credited to Darren Lawrence, with modifications by Tomo Saito.