Important update: Since this article was originally published, Lodestar has released a new version, v1.15.0that Holesky users should upgrade to before Dencun goes live on February 7th. Additionally, both Prysm and Nimbus have released highly recommended versions for Holesky. Prysm users are encouraged to use v4.2.1and Nimbus users v24.2.0.
- Goerli’s blobs are here: Dencun went live on Goerli at 06:32 UTC on January 17, 2024. You can now use blobs there!
- Sepolia and Holesky will be modernized over the next two weeks. Dencun will be active on Sepolia at the time 132608 (January 30, 22:51 UTC), and on Holesky at the time 29696 (February 7, 11:35 UTC).
- The client versions in this announcement are suitable for both test network upgrades.
- Assuming the Sepolia and Holesky upgrades go well, Dencun will next be scheduled to the Ethereum mainnet.
- To receive email alerts regarding network upgrade announcements, including the Dencun mainnet, subscribe here.
The Dencun network upgrade was successfully activated on the Goerli test network on January 17, 2024. It is now scheduled for the two remaining test networks, Sepolia and Holesky, at the following times:
The upgrade includes several changes, including the introduction of ephemeral data blobs with EIP-4844, also known as “protodanksharding,” which will help reduce L2 transaction fees.
Dencun follows last year Shapella Upgrade. It will first be deployed to Ethereum testnets. Once all of these networks have successfully completed the upgrade, Dencun will be scheduled to be deployed to the Ethereum mainnet.
Upgrade Specifications
The Dencun upgrade combines changes to Ethereum’s consensus and execution layers. The full list of protocol changes can be found in EIP-7569For reference, they are:
Deneb
The full Python specification regarding changes affecting Ethereum’s consensus layer can be found in the Deneb case of the ethereum/consensus-specs deposit.
Cancun
The EIPs linked above contain the full specifications of changes affecting Ethereum’s execution layer.
Additionally, a Python specification for these is being implemented in the ethereum/runtime-specifications deposit.
Finally, Deneb requires changes to the engine API, which is used for communication between nodes in the consensus layer and the execution layer. These are specified in the cancun.md deposit of the ethereum/execution-apis deposit.
Client versions
The following client versions support Dencun on both Sepolia and Holesky. Future releases will enable support on the mainnet. Once these are released, another announcement will be made on this blog.
When choosing which client to run, validators should be particularly mindful of the risks of running a majority client on the execution layer (EL) or the consensus layer (CL). An explanation of these risks and their consequences can be found here. An estimate of the current distribution of EL and CL clients and guides for switching from one client to another are available. here.
Consensus layer of Sepolia and Holesky versions
Remarks:
- Holesky Lodestar v1.15.0-rc.0 Users must upgraded to version 1.15.0.
- Holesky Nimbus v24.1.2 users are strongly encouraged to upgrade to version 24.2.0.
- Holesky Prysm v4.2.1-rc.1 users are strongly encouraged to upgrade to version 4.2.1.
- When running a validator, the consensus layer beacon node and the validator client must be updated.
Sepolia and Holesky versions execution layer
Note:while Reth supports Dencun, the client is still waiting for a full audit and is not recommended for production use. See the Reth README for more context.
FAQ
As an Ethereum user or holder, is there anything I should do?
In short, no.
If you’re using an exchange, digital wallet, or hardware wallet, you don’t need to do anything unless your exchange or wallet provider asks you to take additional steps.
If you are running your own Ethereum node, see the next question.
As non-staking Sepolia or Holesky Node operator, what should I do?
To be compatible with the upgrade on either testnet, update your node’s execution and consensus layer clients to the versions listed in the table above.
Inasmuch as Sepolia or Holesky staker, what should I do?
To be compatible with the upgrade on either testnet, update your node’s execution and consensus layer clients to the versions listed in the table above. Make sure your beacon node and validator client are updated.
As a non-Sepolia or Holesky node operator or staker, what should I do?
Nothing yet. Further announcements will be made for Dencun activation on the mainnet. You can sign up to receive an email alert about them here.
Stakers who wish to run the upgrade process multiple times before mainnet are encouraged to use ephemeral.devwhich now supports Dencun.
What if I am a Sepolia or Holesky staker or node operator and I am not participating in the upgrade?
If you are using an Ethereum client that is not updated to the latest version (listed above), your client will sync to the pre-fork blockchain once the upgrade is complete.
You will be stuck on an incompatible chain under the old rules and will not be able to send Ether or operate on the post-Dencun Ethereum network.
As an application or tool developer, what should I do?
Check out the EIPs included in Dencun to determine if and how they affect your project — many exciting new features are introduced in the execution and consensus layers! The only EIPs with backwards compatibility implications are EIP-6780, EIP-7044 And EIP-7514.
Why “Dencun”?
Consensus layer upgrades use star names, and execution layer upgrades follow Devcon city names. “Dencun” is a combination of Deneb, a first-magnitude star in the constellation Cygnus, and Cancun, the location of Devcon 3.
Original cover image by Darren Lawrencewith modifications by Tomo Saito.
