• Withdrawals are coming! The Shapella network upgrade will activate on the Goerli network at epoch 162304, scheduled for 10:25:36 PM UTC on Mar. 14, 2023
• Stakers & node operators should read this post as well as the Withdrawals FAQ
• The Zhejiang testnet can be used to test Shapella functionality prior to the Goerli upgrade
• A Shapella Community Call is scheduled for 15:00 UTC on Mar. 13, 2023
• You can now sign up to receive emails for these upgrade announcements. Scroll to the bottom of the page to do so

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After a smooth Sepolia transition, the Shapella upgrade is now scheduled for the Goerli testnet. This is expected to be the last testnet upgrade before scheduling Shapella for the Ethereum mainnet.

This upgrade follows The Merge and enables validators to withdraw their stake from the Beacon Chain back to the execution layer. It also introduces new functionality to both the execution and consensus layer, described below.

Upgrade Specification

The Shapella upgrade combines changes to the execution layer (Shanghai) and consensus layer (Capella). The Engine API, which is used by the execution and consensus layers to communicate, is also modified in Shapella.

Shanghai

Execution layer changes included in Shanghai are available here. For reference, they are:

Note that EIP-6049 is only a deprecation warning. Client teams expect SELFDESTRUCT semantics to change in future network upgrades, but the opcode’s behavior remains unchanged in Shanghai.

Additionally, the full set of Shanghai changes can now be viewed in the Ethereum Execution Layer Specification (EELS), which is a new Python reference implementation for the execution layer.

Capella

Changes to the consensus layer for the Capella upgrade are specified in the capella directory of the v1.3.0-rc.3 specifications. At a high level, the upgrade introduces:

• Full and partial withdrawals for validators
• BLSToExecutionChange messages, which allow validators using a BLS_WITHDRAWAL_PREFIX to update it to an ETH1_ADDRESS_WITHDRAWAL_PREFIX, a prerequisite for withdrawals
• Independent state and block historical accumulators, replacing the original singular historical roots

Stakers are encouraged to read the Withdrawal FAQ for more information on how they should prepare for Capella.

Engine API

Changes to the Engine API can be found in the shanghai.md file of the execution-apis repository. In short, a WithdrawalV1 structure is introduced and added to various relevant strucutures and methods.

Client Releases

The following client releases support Shanghai & Capella on the Goerli testnet. Note that these releases are only for Goerli. A subsequent announcement will be made for the mainnet releases.

When choosing which client to run, validators should be especially mindful of the risks of running a majority client on both the EL and CL. An explainer of these risks and their consequences can be found here. An estimate of current EL and CL client distribution and guides for switching from one client to another can be found here.

Consensus Layer Goerli Releases

Note: the Lodestar version was previously v1.6.0-rc.0. To avoid any issues, especially if using MEV-boost, users must downgrade to v1.5.1.

Execution Layer Goerli Releases

Note: the go-ethereum version was previously v1.11.3. To avoid potential transaction pool issues, users should update to v1.11.4.

FAQ

As an Ethereum user or Ether holder, is there anything I need to do?

In short, no.

If you use an exchange, digital wallet or hardware wallet you do not need to do anything unless you are informed to take additional steps by your exchange or wallet provider.

If you run your own Ethereum node or validator, see the next questions.

As a non-staking node operator, what do I need to do?

To be compatible with the Goerli upgrade, update your node to the version of your Ethereum client listed in the table above.

As a staker, what do I need to do?

To be compatible with the Goerli upgrade, update your node to the version of your Ethereum client listed in the table above.

We recommend reading the Withdrawal FAQ. Additionally, you can test things on the ephemeral Zhejiang testnet prior to the upgrade activating on Goerli.

Note that Goerli will be the last testnet upgrade before mainnet. In other words, last call to test your setup! If you have questions, we recommend you join the Shapella Community Call.

What happens if I am a staker or node operator and I do not participate 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 occurs.

You will be stuck on an incompatible chain following the old rules and will be unable to send Ether or operate on the post-Shapella Ethereum network.

As an application or tooling developer, what should I do?

Shapella does not introduce breaking changes for smart contracts. Application and tooling developers should review the upgrade changes to ensure any fixes are done, or to understand how to use newly introduced functionality.

Why “Shapella”?

Upgrades to the execution layer follow Devcon city names and those to the consensus layer follow star names. “Shapella” is the combination of Shanghai, the location of Devcon 2, and Capella, the brightest star in the northern constellation of Auriga.

Where Can I Monitor The Upgrade?

EthStaker are hosting a livestream during the Goerli upgrade. You can view it here.

Help – I Still Have Questions!

If you have more questions, you can join the Shapella Community Call on March 13 at 15:00 UTC. Client developers, researchers, and others will be there to answer questions.

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Cover image by Yiran Ding

March 18, 2024 update: The Dencun network upgrade successfully activated on the Ethereum mainnet on March 13, 2024. As per the original wording of this announcement, this would imply an April 13, 2024 sunset date for the Goerli testnet.

That said, as of this writing, nearly all Goerli validators, which were run altruistically by various community members, have already been shut down. Goerli users & developers should therefore migrate to Sepolia or Holesky as soon as possible.

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In the coming months, Goerli, Ethereum’s first multi-client testnet, will stop being supported by client and EF testing teams. The Dencun network upgrade will be the last one implemented on the network.

Either three months after the Goerli Dencun activation, or one month after the Dencun mainnet activation, whichever comes later, teams will begin exiting their validators [1]. Anyone relying on Goerli as a stable testnet should migrate elsewhere prior to this.

While Goerli staking is permissionless, client and testing teams’ validators make up a supermajority of the stake. Their exits will therefore affect the stability of the network. Additionally, teams plan to use the occasion to test delayed finality, inactivity leaks and mass-slashings.

Application and tooling developers are encouraged to use Sepolia to test decentralized applications, smart contracts, and other EVM functionality. Its permissioned validator set provides a stable test environment. Alternatively, many local development environments allow for testing against copies of the Ethereum mainnet state.

Stakers and infrastructure providers concerned with protocol-level testing are encouraged to use the newly launched Holesky testnet, where anyone can run a validator. For validator setup testing, stakers should also consider the Ephemery testnet. This network resets weekly and enables lightweight end-to-end testing of the validator lifecycle.

Goerli is currently expected to be the first testnet to activate the Dencun upgrade. Once the Goerli network upgrade date is set, this post will be updated to reflect it. The upgrade will be announced on this blog, and you can sign up to receive an email alert here.

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Goerli was launched and maintained in a way that is emblematic of the Ethereum community: a group of semi-random people showed up to solve a technical problem and ended up building a community as a result. Thank you to everyone who contributed to the network over the years!

One contributor, whom all would agree gave the testnet its soul, deserves a special shout out: Afri Schoedon, thank you for the care and love you gave Görli!

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[1] The dual-deadline approach was chosen to allow client teams the time to deploy a fix to Goerli in the case where a bug with the network upgrade was found late in the deployment process.

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Cover image originally from Boris Niehaus on Wikipedia, and adapted by Tomo Saito.

• The blobs are coming: Dencun will go live on Goerli at 6:32 UTC on January 17, 2024.
• Dencun will be Goerli’s last upgrade before core teams stop supporting it. More on this in a previous post.
• Assuming the Goerli upgrade goes well, the Sepolia and Holesky testnets will activate Dencun over the next few weeks.
• To receive an email alert for network upgrade announcements, subscribe here.

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The Dencun network upgrade is scheduled to activate on the Goerli testnet at 6:32 UTC on January 17, 2024. The upgrade includes several changes, most notably the introduction of ephemeral data blobs with EIP-4844, also known as “protodanksharding”, which will help reduce L2 transaction fees.

Dencun follows last year’s Shapella upgrade. It will first be deployed to the Goerli testnet. Then, if no major issues are found, to Sepolia and Holesky. Once Dencun is running smoothly on all three testnets, mainnet activation will be scheduled.

Dencun will be Goerli’s last upgrade. After it has been activated on mainnet, client and EF testing teams will stop supporting the Goerli testnet. For more details, see this previous announcement.

Upgrade Specification

The Dencun upgrade combines changes to both Ethereum’s consensus and execution layers. The full list of protocol changes can be found in EIP-7569. For reference, they are:

Deneb

Complete python specifications for changes affecting Ethereum’s consensus layer can be found in the deneb folder of the ethereum/consensus-specs repository.

Cancun

The EIPs linked above contain the full specifications for changes affecting Ethereum’s execution layer.

Additionally, a python specification for these is being implemented in the ethereum/execution-specs repository.

Lastly, Deneb requires changes to the Engine API, used for communication between the consensus and execution layer nodes. These are specified in the cancun.md file of the ethereum/execution-apis repository.

Client Releases

The following client releases support Dencun on Goerli. Further versions will activate support on other testnets and mainnet. Once these are released, another announcement will be made here.

When choosing which client to run, validators should be especially mindful of the risks of running a majority client on either the execution layer (EL) or consensus layer (CL). An explainer of these risks and their consequences can be found here. An estimate of current EL and CL client distribution and guides for switching from one client to another can be found here.

Consensus Layer Goerli Releases

Note: when running a validator, both the Consensus Layer Beacon Node and Validator Client must be updated.

Execution Layer Goerli Releases

Note: while Reth supports Dencun, the client is still pending a full audit and is not recommended for production use. See the Reth README for more context.

Dencun Bug Bounty Bonus

All Dencun-related bug bounties for in-scope vulnerabilities will receive a 2x multiplier between now and two weeks prior to when the mainnet upgrade is scheduled to take place. Critical bugs are now worth up to $500,000 USD! See the bug bounty program for more details.

FAQ

As an Ethereum user or Ether holder, is there anything I need to do?

In short, no.

If you use an exchange, digital wallet or hardware wallet you do not need to do anything unless you are informed to take additional steps by your exchange or wallet provider.

If you run your own Ethereum node, see the next question.

As a non-staking Goerli node operator, what do I need to do?

To be compatible with the Goerli upgrade, update your node to the version of your Ethereum client listed in the table above.

As a Goerli staker, what do I need to do?

To be compatible with the Goerli upgrade, update your node to the version of your Ethereum client listed in the table above. Make sure both your beacon node and validator client are updated!

As a non-Goerli node operator or staker, what do I need to do?

Nothing for now. Further announcements will be made for Dencun’s activation on Sepolia, Holesky and mainnet. You can sign up to receive an email alert for them here.

Stakers who want to run through the upgrade process more times before mainnet are encouraged to use ephemery.dev, which will soon support Dencun.

What happens if I am a Goerli staker or node operator and I do not participate 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 occurs.

You will be stuck on an incompatible chain following the old rules and will be unable to send Ether or operate on the post-Dencun Ethereum network.

As an application or tooling developer, what should I do?

Review the EIPs included in Dencun to determine if and how they affect your project — there are many new exciting features being introduced across both the execution and consensus layers! The only EIPs with backwards compatibility implications are EIP-6780, EIP-7044 and EIP-7514.

Where can I follow the upgrade happening?

The Goerli upgrade will be livestreamed here.

Why “Dencun”?

Upgrades to the consensus layer use star names, and those to the execution layer follow Devcon city names. “Dencun” is the combination of Deneb, a first-magnitude star in the Cygnus constellation, and Cancun, the location for Devcon 3.

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Original cover image by Darren Lawrence, with modifications by Tomo Saito.