ethereum-optimism · sbvegan · Nov 12, 2025 · Nov 12, 2025
@@ -15,7 +15,7 @@

 Upgrade 16 contains these main changes:

 *   **Interop-Ready smart contracts**: Interoperability is critical to realizing the Superchain as a unified network of OP Chains. This upgrade begins the rollout of foundational interoperability features by updating the `OptimismPortal` to handle future cross-chain messaging safely and extensibly. This upgrade does not turn on interop yet.
 *   **Stage 1 updates**: Modifications to meet [L2Beat's updated Stage 1 requirements](https://forum.l2beat.com/t/stages-update-a-high-level-guiding-principle-for-stage-1/338) from January 2025, including removal of `DeputyGuardianModule` and updates to `DeputyPauseModule`.
 *   **Go 1.23 Support in Cannon**: Updates to Cannon to support Go 1.23, allowing OP Stack to benefit from upstream go-ethereum changes.
 *   **Max gas limit increase**: Update to `MAX_GAS_LIMIT` from 200m to 500m gas after improvements to OP Stack infrastructure and the Cannon proof system.
@@ -31,7 +31,7 @@

 Chain operators should be aware that Upgrade 16 involves a one-time invalidation of all existing withdrawal proofs. Users who have proven withdrawals can either finalize withdrawals prior to the activation of Upgrade 16 or will be required to re-prove these withdrawals after the upgrade activates.

 If this proposal is accepted, multisig ceremonies will be coordinated to execute upgrade transactions. The following transactions will be executed on the respective chains: `OP`, `Soneium`, `Ink` and `Unichain` on both Mainnet and Sepolia. Depending on the current state of the chain the execution times will vary. If your Optimism governed chain is not in this list, please reach out to OP Labs Solutions Engineering to coordinate your upgrade. These upgrade tasks will be prepared in the [superchain-ops repo](https://github.com/ethereum-optimism/superchain-ops/tree/main/src/improvements/tasks).

 The tentative execution dates of these upgrades tasks can be tracked in our [release board](https://github.com/orgs/ethereum-optimism/projects/117/views/12).

@@ -141,3 +141,6 @@
 
 *   Changes to the bridge contracts were audited via a Cantina contest with no Medium+ severity issues found
 *   Upgrade 16 as a whole was audited by Spearbit with no Medium+ severity issues found
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@@ -5,7 +5,7 @@



 Upgrade 16a is a **maintenance release that supersedes Upgrade 16**. If you are on upgrade 15 **please skip** upgrade 16 and go straight to this upgrade. It temporarily removes unused interop withdrawal-proving code introduced in Upgrade 16 and adds system-level feature toggles to improve flexibility and rollout safety. These changes reduce risk while maintaining momentum toward the Superchain roadmap.

 <Info>
  The Upgrade 16a protocol upgrade on the **Sepolia** Superchain will be executed on **Mon, Sept 22, 2025**, and the **Mainnet** Superchain will be activated on **Thur, Oct 2, 2025**.
@@ -17,10 +17,10 @@

 Upgrade 16a introduces the following changes:

 **Removal of interop withdrawal-proving code**: Code paths for interop withdrawals added in Upgrade 16 have been removed following partner feedback. ETHLockbox remains supported on chains already running U16. Chains moving directly from U15 → U16a will not adopt ETHLockbox until a future upgrade.

 **System-level feature toggles**
 Added via the `SystemConfig` contract. ETHLockbox is the first feature placed behind a toggle. This mechanism enables chain-specific configuration and safer iterative upgrades.

 **Development-only feature flags**
 Introduced to allow testing of interop functionality on non-production environments. These flags cannot be enabled on production chains.
@@ -33,7 +33,7 @@
 *   No chain downtime is expected, however if upgrading from U15, withdrawals will be invalidated (see below).
 *   Withdrawal proofs created under U16 remain valid.
 *   Chains still on U15 are affected in the same way described in the Upgrade 16 notice.
 *   Chains upgrading directly from U15 → U16a will not adopt ETHLockbox until a future release.
 *   System-level toggles improve operator control and make future upgrades easier to roll out.

 ## For chain operators
@@ -118,3 +118,6 @@
 4.  If a withdrawal was invalidated, submit a second withdrawal proof transaction on L1
 
 This invalidation does not place any ETH or ERC-20 tokens at risk.
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@@ -49,8 +49,8 @@

 **For operators using an external L1 Ethereum Beacon:**

 Before the Ethereum Fusaka hard fork, ensure your external L1 Beacon Chain RPC provider has configured their node to subscribe to all subnets.
 If your external L1 Beacon Chain RPC provider doesn't subscribe to all subnets, migrate to one that does prior to these deadlines.

 **For operators running their own L1 Ethereum Beacon Chain Node:**

@@ -64,7 +64,7 @@

 *   Lighthouse:	`--supernode`
 *   Teku:	`--p2p-subscribe-all-custody-subnets-enabled`
 *   Grandine:	`--subscribe-all-data-column-subnets`
 *   Lodestar:	`--supernode`
 *   Nimbus:	`--debug-peerdas-supernode`

@@ -76,15 +76,15 @@
 | --------------- | ----------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `proxyd`        | [v4.19.0](https://github.com/ethereum-optimism/infra/releases/tag/proxyd%2Fv4.19.0) or greater        | You need to whitelist `eth_blobBaseFee` rpc if using proxyd for L1 load balancing. If you use `dugtrio` ensure this is also updated to the latest release.                                                                                                              |
 | `op-batcher`    | [v1.16.2](https://github.com/ethereum-optimism/optimism/releases/tag/op-batcher%2Fv1.16.2)            | The `op-batcher` must be restarted at least once after updating `op-node` to the latest release. The batcher loads the rollup config once at startup and this will need to happen to update the activation timestamps for Jovian. We've opened this [issue](https://github.com/ethereum-optimism/optimism/issues/18178) to improve this experience in the future.                       |
 | `op-node`       | [v1.16.1](https://github.com/ethereum-optimism/optimism/releases/tag/op-node%2Fv1.16.1)               | L1 chain config must be supplied via a new flag (see the release notes). Not necessary for chains deriving from Ethereum Mainnet, Sepolia, Holesky or Hoodi.                                            |
 | `op-geth`       | [v1.101603.4](https://github.com/ethereum-optimism/op-geth/releases/tag/v1.101603.4)                  |                                                                                                                                                                                                |
 | `op-challenger` | [v1.7.0](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger%2Fv1.7.0)           | If deriving from a chain other than Ethereum Mainnet, Sepolia or Hoodi then L1 chain config must be supplied via a new flag.                                            |
 | `kona-node`     | [v1.2.2](https://github.com/op-rs/kona/releases/tag/kona-node%2Fv1.2.2)                               |                                                                                                                                                                                                |
 | `kona-host`     | [v1.2.2](https://github.com/op-rs/kona/releases/tag/kona-host%2Fv1.2.2)                     |                                                                                                                                                                                                |
 | `kona-client`   | [v1.2.2](https://github.com/op-rs/kona/releases/tag/kona-client%2Fv1.2.2)                   |                                                                                                                                                                                                |
 | `op-reth`       | [v1.9.1](https://github.com/paradigmxyz/reth/releases/tag/v1.9.1)                                     |                                                                                                                                                                                                |
-| `op-rbuilder`   | []() | New releases will be published after this [PR](https://github.com/flashbots/op-rbuilder/pull/313) is merged. | 
-| `rollup-boost`  | []() | New releases will be published after this [PR](https://github.com/flashbots/rollup-boost/pull/431) is merged. | 
+| `op-rbuilder`   | [v0.2.9](https://github.com/flashbots/op-rbuilder/releases/tag/op-rbuilder%2Fv0.2.9) |  | 
+| `rollup-boost`  | [v0.7.8](https://github.com/flashbots/rollup-boost/releases/tag/rollup-boost%2Fv0.7.8) |  | 
 
 <Info>
 **Note:** `op-node` uses the new `/eth/v1/beacon/blobs/` API for fetching blob data from L1 beacon nodes. If you run a proxy/load balancer in front of your beacon API, ensure it correctly forwards all query parameters. 

@@ -90,15 +90,15 @@
 | --------------- | ----------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `proxyd`        | [v4.19.0](https://github.com/ethereum-optimism/infra/releases/tag/proxyd%2Fv4.19.0) or greater        | You need to whitelist `eth_blobBaseFee` rpc if using proxyd for L1 load balancing. If you use `dugtrio` ensure this is also updated to the latest release.                                                                                                              |
 | `op-batcher`    | [v1.16.2](https://github.com/ethereum-optimism/optimism/releases/tag/op-batcher%2Fv1.16.2)            | The `op-batcher` must be restarted at least once after updating `op-node` to the latest release. The batcher loads the rollup config once at startup and this will need to happen to update the activation timestamps for Jovian. We've opened this [issue](https://github.com/ethereum-optimism/optimism/issues/18178) to improve this experience in the future.                       |
 | `op-node`       | [v1.16.1](https://github.com/ethereum-optimism/optimism/releases/tag/op-node%2Fv1.16.1)               | L1 chain config must be supplied via a new flag (see the release notes). Not necessary for chains deriving from Ethereum Mainnet, Sepolia, Holesky or Hoodi.                                            |
 | `op-geth`       | [v1.101603.4](https://github.com/ethereum-optimism/op-geth/releases/tag/v1.101603.4)                  |                                                                                                                                                                                                |
 | `op-challenger` | [v1.7.0](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger%2Fv1.7.0)           | If deriving from a chain other than Ethereum Mainnet, Sepolia or Hoodi then L1 chain config must be supplied via a new flag.                                            |
 | `kona-node`     | [v1.2.2](https://github.com/op-rs/kona/releases/tag/kona-node%2Fv1.2.2)                               |                                                                                                                                                                                                |
 | `kona-host`     | [v1.2.2](https://github.com/op-rs/kona/releases/tag/kona-host%2Fv1.2.2)                     |                                                                                                                                                                                                |
 | `kona-client`   | [v1.2.2](https://github.com/op-rs/kona/releases/tag/kona-client%2Fv1.2.2)                   |                                                                                                                                                                                                |
 | `op-reth`       | [v1.9.1](https://github.com/paradigmxyz/reth/releases/tag/v1.9.1)                                     |                                                                                                                                                                                                |
-| `op-rbuilder`   | []() | New releases will be published after this [PR](https://github.com/flashbots/op-rbuilder/pull/313) is merged. | 
-| `rollup-boost`  | []() | New releases will be published after this [PR](https://github.com/flashbots/rollup-boost/pull/431) is merged. | 
+| `op-rbuilder`   | [v0.2.9](https://github.com/flashbots/op-rbuilder/releases/tag/op-rbuilder%2Fv0.2.9) |  | 
+| `rollup-boost`  | [v0.7.8](https://github.com/flashbots/rollup-boost/releases/tag/rollup-boost%2Fv0.7.8) |  | 
 
 ### For permissionless fault proof enabled chains