Kernel upgrades

This page lists the major updates to the Etherlink kernel.

Mainnet beta

The Mainnet beta was the final step before launching Etherlink. For more information, see Etherlink Mainnet Beta: Paving the Way to Launch

First kernel upgrade

The first upgrade to the Etherlink kernel went live on Etherlink Mainnet on 22 July 2024. It includes updates and improvements to Etherlink's support for EVM endpoints to make calling Etherlink more similar to calling any other EVM network. For more information, see The First Regular Upgrade for Etherlink: One Step Closer to Launch.

Etherlink 2 (Bifröst)

The 2.0 upgrade to the Etherlink kernel went live on Etherlink Mainnet on 7 November 2024. It adds support for bridging FA tokens from Tezos layer 1 to ERC-20 tokens on Etherlink and support for the callTracer tracer, which makes it possible for third-party tools like the Blockscout block explorer to index Etherlink transactions and for applications to trace transactions as described in Tracing transactions. For more information, see Announcing Bifröst: a 2nd upgrade proposal for Etherlink Mainnet.

Etherlink 3 (Calypso)

The 3.0 upgrade to the Etherlink kernel went live on Etherlink Mainnet on 4 March 2025.

This upgrade includes significant performance and reliability improvements, including:

• Caching in the virtual machine to improve read and write performance on storage indexes, leading to faster interaction with smart contracts
• Reduced disk footprint for Etherlink Smart Rollup nodes, which now store only the latest block in the Smart Rollup context; the full history remains available in Etherlink EVM nodes
• Updated governance contracts to align periods with Quebec changes in block time
• Events generated by the kernel to notify the sequencer of delayed transaction flushes, reducing downtime risks caused by unforeseen events

The upgrade also includes foundational work to the withdrawal precompiled contract that is a step toward allowing faster withdrawals from Etherlink to Tezos layer 1.

For more information, see Announcing Calypso: The Next Etherlink Upgrade Proposal

Etherlink 3.1 (Calypso2)

On 12 April 2025, the 3.1 security upgrade went live on Etherlink Mainnet, in Etherlink block 10,453,254. This upgrade improves error handling of FA bridging transactions, which hardens the Etherlink sequencer against potential DDOS attacks. This upgrade includes only a security patch for the Calypso kernel and no other changes.

This upgrade was carried out through Etherlink’s security governance process.

For more information, see Calypso2: A security upgrade to harden the Etherlink sequencer and FA bridge.

Etherlink 4.0 (Dionysus)

On 21 May 2025, the 4.0 kernel upgrade went live on Etherlink Mainnet, in Etherlink block 15,262,162. This upgrade includes:

• Support for EVM version Cancun features
• Foundational work to allow faster withdrawals of FA tokens to Tezos layer 1
• Improvements to gas price computation logic to reduce the effect of price spikes
• The ability for the sequencer to publish blocks via the Data Availability Layer
• Upgraded governance contracts to be compatible with the Tezos Rio upgrade

Running an Etherlink EVM node on Dionysus requires version 0.26 or later of the octez-evm-node binary.

For more information, see Announcing Dionysus: The Next Etherlink Upgrade Proposal.

Etherlink 4.1

On 15 July 2025, the 4.1 upgrade went live on Etherlink Mainnet, in Etherlink block 21,214,618. This upgrade includes:

• An updated governance process that allows bakers to authenticate on voting contracts using voting keys
• The speed limit is increased from 2 million gas units per second to 4 million gas units per second, increasing the transaction throughput that Etherlink accepts before raising the gas price
• Improvements to gas limit calculations that prevent over-estimation of gas prices from blocking transactions that would have completed successfully.

For more information, see It’s voting month for Etherlink: Two governance votes coming in July 2025.

Etherlink 5.0 (Ebisu)

The Etherlink 5.0 upgrade includes:

• Support for EVM Prague, including support for EIP-7702, EIP-2537, and EIP-7623, including the precompiled contracts in EIP-2537. Note that EIP-7623 causes a breaking change in the way that transaction fees are calculated, especially for transactions posting larger amounts of data on-chain, which may result in slightly higher gas fees.

• Changes to the events that are emitted for bridging operations of FA tokens.

• The speed limit (also known as the target) is increased to 7 million gas units per second. The speed limit decides when the gas price raises. For more information, see Execution fee.

• The sequencer operator can now replace its signing key with a new one without needing to go through a governance vote.

For more information, see Announcing Ebisu: A 5th Upgrade proposal for Etherlink Mainnet.

Etherlink 6.0 (Farfadet)

Etherlink 6.0 requires version 0.48 or later of the octez-evm-node binary.

The Etherlink 6.0 upgrade includes:

• Support for EVM Osaka, including support for the count leading zeroes (CLZ) opcode (EIP-7939), the ecp256r1 Curve Support precompile (EIP-7951), and the increase in ModExp gas cost (EIP-7883)

• The ability to provide instant confirmations, which allow users to know (within roughly 50ms) that their transactions will be in the next block and receive receipts with information about the completed transaction. This update puts the functionality for instant confirmations in the kernel, but they are not available to users until the EVM node enables the functionality.

• The speed limit (also known as the target) is increased to 13.5 million gas units per second. The speed limit decides when the gas price raises. For more information, see Execution fee.

• A breaking change to the QueuedDeposit event that the FA bridge emits. This event is now emitted by the FA bridging precompiled contract (0xff0...0002) and the first topic of the event is changed to match its ABI signature. For more information about bridging events, see How bridging FA tokens works.

For more information, see Announcing Farfadet: A 6th Upgrade Proposal for Etherlink Mainnet.

Changelog

For full details about changes to Etherlink, see Changelogs.