Isthmus: operator fee

specs/SUMMARY.md

@@ -55,10 +55,14 @@
       - [Execution Engine](./protocol/holocene/exec-engine.md)
       - [System Config](./protocol/holocene/system-config.md)
     - [Isthmus](./protocol/isthmus/overview.md)
+      - [Configurability](./protocol/isthmus/configurability.md)
+      - [Derivation](./protocol/isthmus/derivation.md)
       - [Execution Engine](./protocol/isthmus/exec-engine.md)
       - [Derivation](./protocol/isthmus/derivation.md)
+      - [L1 Attributes](./protocol/isthmus/l1-attributes.md)
       - [Predeploys](./protocol/isthmus/predeploys.md)
       - [Superchain Config](./protocol/isthmus/superchain-config.md)
+      - [System Config](./protocol/isthmus/system-config.md)
 - [Governance]()
   - [Governance Token](./governance/gov-token.md)
 - [Experimental]()

specs/protocol/configurability.md

@@ -30,6 +30,8 @@
   - [Start block](#start-block)
   - [Superchain target](#superchain-target)
   - [Governance Token](#governance-token)
+  - [Operator Fee Scalar](#operator-fee-scalar)
+  - [Operator Fee Constant](#operator-fee-constant)
   - [Resource Config](#resource-config)
 - [Policy Parameters](#policy-parameters)
   - [Data Availability Type](#data-availability-type)
@@ -47,6 +49,7 @@
   - [Guardian address](#guardian-address)
   - [Proposer address](#proposer-address)
   - [Sequencer P2P / Unsafe head signer](#sequencer-p2p--unsafe-head-signer)
+  - [Operator Fee Manager](#operator-fee-manager)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 
@@ -283,6 +286,21 @@ contracts deployed on layer 1.<br/>
 **Requirement:** Disabled<br/>
 **Notes:** Simple clear restriction.<br/>
 
+### [Operator Fee Scalar](exec-engine.md#operator-fees)
+
+**Description:** Operator fee scalar -- used to calculate the operator fee<br/>
+**Administrator:** [Operator Fee Manager](#operator-fee-manager)<br/>
+**Requirement:** 0 <br/>
+
+### [Operator Fee Constant](exec-engine.md#operator-fees)
+
+**Description:** Operator fee constant -- used to calculate the operator fee<br/>
+**Administrator:** [Operator Fee Manager](#operator-fee-manager)<br/>
+**Requirement:** 0 <br/>
+
+Note that the operator fee scalar and constant are primarily used for non-standard configurations,
+like op-succinct, so their standard values are 0.
+
 [^chain-id-uniqueness]: The chain ID must be globally unique among all EVM chains.
 
 ### Resource Config
@@ -441,4 +459,11 @@ configuration of the permissioned dispute game.<br/>
 **Requirement:** No requirement<br/>
 **Notes:** <br/>
 
+### Operator Fee Manager
+
+**Description:** Account authorized to modify the operator fee scalar. <br/>
+**Administrator:** [System Config Owner](#admin-roles)<br/>
+**Requirement:** `address(0)`<br/>
+**Notes:** For standard configurations, the operator fee manager is not used, so it is set to the null address. <br/>
+
 [^of-gnosis-safe-l1]: 5 of 7 GnosisSafe controlled by Optimism Foundation (OF). Mainnet and Sepolia addresses can be found at [privileged roles](https://docs.optimism.io/chain/security/privileged-roles).

specs/protocol/isthmus/configurability.md

@@ -10,11 +10,12 @@
 - [`SystemConfig`](#systemconfig)
   - [`ConfigUpdate`](#configupdate)
   - [Initialization](#initialization)
+  - [Modifying Operator Fee Parameters](#modifying-operator-fee-parameters)
   - [Interface](#interface)
-    - [Fee Vault Config](#fee-vault-config)
-      - [`setBaseFeeVaultConfig`](#setbasefeevaultconfig)
-      - [`setL1FeeVaultConfig`](#setl1feevaultconfig)
-      - [`setSequencerFeeVaultConfig`](#setsequencerfeevaultconfig)
+    - [Operator fee parameters](#operator-fee-parameters)
+      - [`operatorFeeScalar`](#operatorfeescalar)
+      - [`operatorFeeConstant`](#operatorfeeconstant)
+      - [`setOperatorFeeScalars`](#setoperatorfeescalars)
 - [`OptimismPortal`](#optimismportal)
   - [Interface](#interface-1)
     - [`setConfig`](#setconfig)
@@ -25,7 +26,7 @@
 ## Overview
 
 The `SystemConfig` and `OptimismPortal` are updated with a new flow for chain
-configurability.
+configurability. A new service role `OperatorFeeManager` is added to manage the operator fee collection.
 
 ## Constants
 
@@ -39,10 +40,11 @@ The `ConfigType` enum represents configuration that can be modified.
 | `BASE_FEE_VAULT_CONFIG` | `uint8(1)` | Sets the Fee Vault Config for the `BaseFeeVault` |
 | `L1_FEE_VAULT_CONFIG` | `uint8(2)` | Sets the Fee Vault Config for the `L1FeeVault` |
 | `SEQUENCER_FEE_VAULT_CONFIG` | `uint8(3)` | Sets the Fee Vault Config for the `SequencerFeeVault` |
-| `L1_CROSS_DOMAIN_MESSENGER_ADDRESS` | `uint8(4)` | Sets the `L1CrossDomainMessenger` address |
-| `L1_ERC_721_BRIDGE_ADDRESS` | `uint8(5)` | Sets the `L1ERC721Bridge` address |
-| `L1_STANDARD_BRIDGE_ADDRESS` | `uint8(6)` | Sets the `L1StandardBridge` address |
-| `REMOTE_CHAIN_ID` | `uint8(7)` | Sets the chain id of the base chain |
+| `OPERATOR_FEE_VAULT_CONFIG` | `uint8(4)` | Sets the Fee Vault Config for the `OperatorFeeVault` |
+| `L1_CROSS_DOMAIN_MESSENGER_ADDRESS` | `uint8(5)` | Sets the `L1CrossDomainMessenger` address |
+| `L1_ERC_721_BRIDGE_ADDRESS` | `uint8(6)` | Sets the `L1ERC721Bridge` address |
+| `L1_STANDARD_BRIDGE_ADDRESS` | `uint8(7)` | Sets the `L1StandardBridge` address |
+| `REMOTE_CHAIN_ID` | `uint8(8)` | Sets the chain id of the base chain |
 
 ## `SystemConfig`
 
@@ -57,6 +59,7 @@ The following `ConfigUpdate` event is defined where the `CONFIG_VERSION` is `uin
 | `GAS_LIMIT` | `uint8(2)` | `abi.encode(uint64 _gasLimit)` | Modifies the L2 gas limit |
 | `UNSAFE_BLOCK_SIGNER` | `uint8(3)` | `abi.encode(address)` | Modifies the account that is authorized to progress the unsafe chain |
 | `EIP_1559_PARAMS` | `uint8(4)` | `uint256(uint64(uint32(_denominator))) << 32 \| uint64(uint32(_elasticity))` | Modifies the EIP-1559 denominator and elasticity |
+| `OPERATOR_FEE_PARAMS` | `uint8(5)` | `uint256(_operatorFeeScalar) << 64 \| _operatorFeeConstant` | Modifies the operator fee parameters |
 
 ### Initialization
 
@@ -67,43 +70,57 @@ The following actions should happen during the initialization of the `SystemConf
 - `emit ConfigUpdate.GAS_LIMIT`
 - `emit ConfigUpdate.UNSAFE_BLOCK_SIGNER`
 - `emit ConfigUpdate.EIP_1559_PARAMS`
+- `emit ConfigUpdate.OPERATOR_FEE_PARAMS`
 - `setConfig(SET_GAS_PAYING_TOKEN)`
 - `setConfig(SET_BASE_FEE_VAULT_CONFIG)`
 - `setConfig(SET_L1_FEE_VAULT_CONFIG)`
 - `setConfig(SET_SEQUENCER_FEE_VAULT_CONFIG)`
+- `setConfig(SET_OPERATOR_FEE_VAULT_CONFIG)`
 - `setConfig(SET_L1_CROSS_DOMAIN_MESSENGER_ADDRESS)`
 - `setConfig(SET_L1_ERC_721_BRIDGE_ADDRESS)`
 - `setConfig(SET_L1_STANDARD_BRIDGE_ADDRESS)`
 - `setConfig(SET_REMOTE_CHAIN_ID)`
 
 These actions MAY only be triggered if there is a diff to the value.
 
-### Interface
+Since the `OperatorFeeVault` is new in Isthmus, the `setConfig(SET_OPERATOR_FEE_VAULT_CONFIG)` MUST be emitted.
+
+`ConfigUpdate.OPERATOR_FEE_PARAMS` MAY be emitted. If it is not emitted, the `operatorFeeScalar` and
+`operatorFeeConstant` are set to 0 by default.
+
+### Modifying Operator Fee Parameters
+
+A new `SystemConfig` `UpdateType` is introduced that enables the modification of
+the `operatorFeeScalar` and `operatorFeeConstant` by the [`OperatorFeeManager`](../configurability.md#operator-fee-manager).
 
-#### Fee Vault Config
+### Interface
 
-For each `FeeVault`, there is a setter for its config. The arguments to the setter include
-the `RECIPIENT`, the `MIN_WITHDRAWAL_AMOUNT` and the `WithdrawalNetwork`.
-Each of these functions should be `public` and only callable by the chain governor.
+#### Operator fee parameters
 
-Each function calls `OptimismPortal.setConfig(ConfigType,bytes)` with its corresponding `ConfigType`.
+##### `operatorFeeScalar`
 
-##### `setBaseFeeVaultConfig`
+This function returns the currently configured operator fee scalar.
 
 ```solidity
-function setBaseFeeVaultConfig(address,uint256,WithdrawalNetwork)
+function operatorFeeScalar()(uint32)
 ```
 
-##### `setL1FeeVaultConfig`
+##### `operatorFeeConstant`
+
+This function returns the currently configured operator fee constant.
 
 ```solidity
-function setL1FeeVaultConfig(address,uint256,WithdrawalNetwork)
+function operatorFeeConstant()(uint64)
 ```
 
-##### `setSequencerFeeVaultConfig`
+##### `setOperatorFeeScalars`
+
+This function sets the `operatorFeeScalar` and `operatorFeeConstant`.
+
+This function MUST only be callable by the [`OperatorFeeManager`](../configurability.md#operator-fee-manager).
 
 ```solidity
-function setSequencerFeeVaultConfig(address,uint256,WithdrawalNetwork)
+function setOperatorFeeScalar(uint32 _operatorFeeScalar, uint64 _operatorFeeConstant)
 ```
 
 ## `OptimismPortal`