Hi I’m Joshua, an engineer at OP Labs. OP Labs is a software development company focused on the Optimism ecosystem, and a core developer of the OP Stack. We provide some services to, but do not represent or speak on behalf of, the Optimism Foundation.
Upgrade #2, Canyon is the first proposed network upgrade after Bedrock. Canyon contains the Shapella network upgrade from Ethereum, a change to reduce the volatility of the basefee, and several minor bug fixes. The Canyon upgrade will maintain EVM equivalence & improve the ergonomics of using the OP Stack for developers and end users. In addition, node operators will need to upgrade their nodes to stay in sync. Canyon brings the OP Stack protocol version to v4.0.0.
If this vote passes, Canyon will activate on
zora-mainnet on Thu Jan 11 17:00:01 UTC 2024 (Unix Time 1704992401) barring a critical security issue. All op-node versions after v1.3.1 & all op-geth versions after v1.101304.1 are compatible with Canyon. We will release a new version of op-node & op-geth with the Canyon activation time baked in if the vote passes governance.
We are activating the following features as part of the Canyon upgrade. Full Canyon Specification in Github.
- EIP-1559 Parameter Changes
- Increasing EIP-1559 Denominator from 50 to 250
- Adjust Channel Ordering
- The first ready channel is now read rather than the first channel when it is ready
- Receipt Hash Change
- The deposit nonce is included in the deposit receipt hash
- We are deploying standardized bytecode to
- We are deploying standardized bytecode to
Consistent with the OP Labs Audit Framework, OP Labs did not have the contents of Canyon audited; however OP Labs did perform a security review of these changes.
The Shapella L1 upgrade consists of relatively standard EVM changes & the addition of beacon chain withdrawals. OP Labs considers the EVM changes low risk because they have been active on L1 without issue. Withdrawals are a new L1 codepath to create arbitrary mints in the EVM. OP Labs has ensured that this type of transaction cannot occur on L2…
The next set of changes, EIP-1559 config change, the channel ordering change, and the receipt hash change also are low risk changes. They do not modify any code path which is responsible for securing user funds and have been tested.
The last change, the create2Deployer, presents a larger user facing change. Canyon unconditionally modifies the bytecode of the
0x13b0D85CcB8bf860b6b79AF3029fCA081AE9beF2 address. This address already has the create2Deployer on it on some, but not all, networks. OP Labs has validated that the contract code deployed by Canyon matches the public ABI of the existing contract. This upgrade does remove portions of the admin ABI (pausing, ownable), but OP Labs has confirmed that the contract author is ok with removing the Ownable & Pausable functionality. A typical developer would not be able to call these functions.
OP Labs does not anticipate any down time due to this upgrade. This network upgrade does not contain backwards incompatible changes for end users.
Shapella is important to retain compatibility with Ethereum. One change to be aware of is the deprecation warning of the SELFDESTRUCT opcode. The behavior of the opcode is not changing in Canyon, but is expected to change in a future network upgrade. Ethereum is expected to implement EIP-6780 in the Dencun network upgrade to modify this opcode, and the Optimism community should expect to follow this change in the spirit of EVM equivalence.
The EIP-1559 Denominator will be changing from 50 to 250. OP Labs is proposing this change to decrease volatility in the basefee on the OP Stack. By increasing the denominator, the amount the basefee increases is reduced when the gas used is over the gas target. A denominator of 50 was initially chosen for Bedrock such that the basefee on the OP Stack would decrease at approximately a rate of -12% per 12s when the block were completely empty. This matches the decrease of Ethereum’s basefee. The rate of increase with completely full blocks was 77% over 12s because the gas limit on the OP Stack is 6x the gas target. Since Bedrock, 2 minutes of full congestion (30m gas blocks) on the OP Stack would result in an increased base fee of ****304x ****(1.1^60) ******vs 2 minutes of full congestion on L1 Ethereum would result in an increased base fee of 3.24x (1.125^10). OP Labs is suggesting a denominator of 250 to match the rate of increase of Ethereum when OP Stack blocks are completely full. This will also reduce how quickly the basefee decays when blocks are empty and will enable users to have their transactions included more easily during periods of high usage.
Canyon modifies the protocol to handle unclosed channels. Previously, only a single channel could be active at a time and if the channel was not closed, it would need to time out before progress could resume. Following the upgrade, the op-node will read the first channel that is ready.
A new field will be added to the deposit transaction receipt encoding. It modifies the encoding to fix a bug where the deposit transaction nonce was not in consensus encoding.
Finally, Canyon sets the create2Deployer bytecode at
0x13b0D85CcB8bf860b6b79AF3029fCA081AE9beF2 on all OP networks. This enables developers to have access to this commonly used contract on all OP networks, not just OP Mainnet. This also particularly helps users on Base mainnet, where, due to a deployment issue, the create2Deployer is not able to be deployed to this address. Block explorers may have to re-verify the create2Deployer contract.
If this vote passes, the Canyon upgrade will be schedule for execution 5 ****weeks after the vote passes, on Thu Jan 11 17:00:01 UTC 2024. The upgrade will occur automatically for nodes on a release which contains the baked in activation time. Canyon is code complete in the optimism monorepo at commit
6cce3728b7bed5e36234aeba3b773e0f97867be3 and op-geth at commit
ed8e9f54ed0a5069e77ea34895ff12a9ac4ca17f. The op-node release v1.3.1 and op-geth release v1.101304.1 contain these changes. These commits do not contain the Canyon timestamp for mainnet. These releases could be used on mainnet by using the
--override.canyon flag. OP Labs will release a future version of op-node & op-geth with the Canyon time configured if governance approves this upgrade.
This upgrade has already been activated on internal devnets in coordination with Base & Conduit. It successfully activated on
zora-sepolia on November 14 at 17:00:00 UTC.
If there is a critical security issue, node operators will be able to disable the upgrade by using the
—override.canyon flag on both op-node & op-geth. OP Labs will also collaborate with the community to extensively communicate that the upgrade is no longer happening.
OP Labs will release a new version of op-node & op-geth with the Canyon activation date baked in and publicize to node operators & end users that the Canyon upgrade will be occurring.
This proposal outlines the Optimism Collective’s first network upgrade after Bedrock titled Canyon. This network upgrade maintains EVM equivalence via activating the Shapella network upgrade and includes several OP Stack specific improvements.
We expect that this upgrade will not result in any down time and will occur at Thu Jan 11 17:00:01 UTC 2024.