Geth v1.16.6 (Leather Wrapping) has been released. This is a mandatory update as it enables the Fusaka hardfork on the Ethereum mainnet.
The fork is scheduled for 2025-12-03 21:49:11 UTC. Please upgrade your node in time to ensure you remain on the correct chain.
This release also schedules the BPO1 and BPO2 forks for mainnet on 2025-12-09 and 2026-01-07, respectively.
RPC API Improvements
A new RPC method, eth_sendRawTransactionSync, has been introduced. It submits a signed transaction and blocks until a receipt is available or a timeout occurs, which is especially useful for L2s. Support has also been added in ethclient for eth_simulateV1, allowing for transaction simulations without affecting the blockchain. Additionally, this release fixes a bug that could cause a crash in debug_traceCall and resolves an issue where local transactions could be lost on shutdown if they were submitted shortly after launch.
Core & Command-Line Changes
Setting up a new node is now more convenient with the new geth --genesis flag, which serves as a direct alternative to running geth init genesis.json. This release also features continued progress on the path-based archive node, enhancing its ability to serve historical eth_getProof requests.
Networking & Performance
New metrics have been added to help node operators better monitor network health by tracking the number of slow peers and the time it takes for them to become responsive again. The transaction fetcher was also improved to ensure disconnected peers are properly removed. The release includes various other optimizations and bug fixes to improve node stability and performance.
<!-- Leather Wrapping (v1.16.6) --> **This release enables the Fusaka hardfork on Ethereum mainnet**. The fork is scheduled to occur at `2025-12-03 21:49:11 UTC`. Please upgrade your node in time. This release also enables the BPO1 and BPO2 forks for mainnet at `2025-12-09` and `2026-01-07` respectively. ### Fusaka * Set mainnet timestamps for Osaka ([#33063](https://github.com/ethereum/go-ethereum/pull/33063)) * Enable Fusaka for `geth --dev` mode ([#32917](https://github.com/ethereum/go-ethereum/pull/32917)) ### RPC * Add `eth_sendRawTransactionSync` which waits until either a timeout or the transaction is mined. This feature is mostly useful on L2s with lower blocktimes. ([#32830](https://github.com/ethereum/go-ethereum/pull/32830), [#32930](https://github.com/ethereum/go-ethereum/pull/32930), [#32929](https://github.com/ethereum/go-ethereum/pull/32929/)) * Add support for `eth_simulateV1` in ethclient ([#32856](https://github.com/ethereum/go-ethereum/pull/32856)) * Fix for an issue that might crash `debug_traceCall` ([#33015](https://github.com/ethereum/go-ethereum/pull/33015)) * Fix for an issuer where local transactions were not persisted to the journal ([#32921](https://github.com/ethereum/go-ethereum/pull/32921)) ### Core * Add `geth --genesis` flag as an alternative to running `geth init genesis.json` ([#32844](https://github.com/ethereum/go-ethereum/pull/32844)) * Fix for receipt insertion during ERA file import. ([#32934](https://github.com/ethereum/go-ethereum/pull/32934)) * Work on getting the trie node history in order to serve historical `eth_getProof` request with the new path-based archive node. ([#32907](https://github.com/ethereum/go-ethereum/pull/32907), [#32914](https://github.com/ethereum/go-ethereum/pull/32914), [#32937](https://github.com/ethereum/go-ethereum/pull/32937)) * Further work on cmd/keeper, our guest program for zkVMs ([#32816](https://github.com/ethereum/go-ethereum/pull/32816)) * Various optimizations ([#32971](https://github.com/ethereum/go-ethereum/pull/32971), [#32916](https://github.com/ethereum/go-ethereum/pull/32916), [#32965](https://github.com/ethereum/go-ethereum/pull/32965), [#32946](https://github.com/ethereum/go-ethereum/pull/32946)) ### Networking * New metrics for tracking slow peers ([#32964](https://github.com/ethereum/go-ethereum/pull/32964)) * Fix for an issue where disconnected peers were not removed in txFetcher ([#32947](https://github.com/ethereum/go-ethereum/pull/32947)) For a full rundown of the changes please consult the Geth 1.16.6 [release milestone](https://github.com/ethereum/go-ethereum/milestone/195?closed=1). --- As with all our previous releases, you can find the: - Pre-built binaries for all platforms on our [downloads page](https://geth.ethereum.org/downloads/). - Docker images published under [`ethereum/client-go`](https://cloud.docker.com/u/ethereum/repository/docker/ethereum/client-go). - Ubuntu packages in our [Launchpad PPA repository](https://launchpad.net/~ethereum/+archive/ubuntu/ethereum). - OSX packages in our [Homebrew Tap repository](https://github.com/ethereum/homebrew-ethereum).