add L2GasPriceOracle and Version

contracts/docs/apis/L1ERC1155Gateway.md

@@ -366,6 +366,23 @@ Update layer 2 to layer 2 token mapping.
 | _l1Token | address | The address of corresponding ERC1155 token in layer 2. |
 | _l2Token | address | undefined |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 
 
 ## Events

contracts/docs/apis/L1ERC721Gateway.md

@@ -311,6 +311,23 @@ Update layer 2 to layer 2 token mapping.
 | _l1Token | address | The address of corresponding ERC721 token in layer 2. |
 | _l2Token | address | undefined |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 
 
 ## Events

contracts/docs/apis/L1GatewayRouter.md

@@ -380,6 +380,23 @@ function transferOwnership(address newOwner) external nonpayable
 |---|---|---|
 | newOwner | address | undefined |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 
 
 ## Events

contracts/docs/apis/L1ScrollMessenger.md

@@ -369,6 +369,23 @@ Update whitelist contract.
 |---|---|---|
 | _newWhitelist | address | The address of new whitelist contract. |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 ### whitelist
 
 ```solidity

contracts/docs/apis/L1StandardERC20Gateway.md

@@ -226,6 +226,23 @@ The address of L1GatewayRouter/L2GatewayRouter contract.
 |---|---|---|
 | _0 | address | undefined |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 
 
 ## Events

contracts/docs/apis/L1WETHGateway.md

@@ -226,6 +226,23 @@ The address of L1GatewayRouter/L2GatewayRouter contract.
 |---|---|---|
 | _0 | address | undefined |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 
 
 ## Events

contracts/docs/apis/L2ERC1155Gateway.md

@@ -327,6 +327,23 @@ Update layer 2 to layer 1 token mapping.
 | _l2Token | address | undefined |
 | _l1Token | address | The address of ERC1155 token in layer 1. |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 ### withdrawERC1155
 
 ```solidity

contracts/docs/apis/L2ERC721Gateway.md

@@ -274,6 +274,23 @@ Update layer 2 to layer 1 token mapping.
 | _l2Token | address | undefined |
 | _l1Token | address | The address of ERC721 token in layer 1. |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 ### withdrawERC721
 
 ```solidity

contracts/docs/apis/L2GatewayRouter.md

@@ -312,6 +312,23 @@ function transferOwnership(address newOwner) external nonpayable
 |---|---|---|
 | newOwner | address | undefined |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 ### withdrawERC20
 
 ```solidity

contracts/docs/apis/L2ScrollMessenger.md

@@ -295,6 +295,23 @@ Update whitelist contract.
 |---|---|---|
 | _newWhitelist | address | The address of new whitelist contract. |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 ### whitelist
 
 ```solidity

contracts/docs/apis/L2StandardERC20Gateway.md

@@ -173,6 +173,23 @@ The address of ScrollStandardERC20Factory.
 |---|---|---|
 | _0 | address | undefined |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 ### withdrawERC20
 
 ```solidity

contracts/docs/apis/L2WETHGateway.md

@@ -191,6 +191,23 @@ The address of L1GatewayRouter/L2GatewayRouter contract.
 |---|---|---|
 | _0 | address | undefined |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 ### withdrawERC20
 
 ```solidity

contracts/docs/apis/ZKRollup.md

@@ -364,6 +364,23 @@ Update the address of operator.
 |---|---|---|
 | _newOperator | address | The new operator address to update. |
 
+### version
+
+```solidity
+function version() external view returns (string)
+```
+
+the current contract version.
+
+
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | string | undefined |
+
 
 
 ## Events

contracts/integration-test/L1BlockContainer.spec.ts

@@ -129,6 +129,7 @@ describe("L1BlockContainer", async () => {
           test.parentHash,
           test.blockHeight - 1,
           test.blockTimestamp - 1,
+          test.baseFee,
           test.stateRoot
         );
         const Whitelist = await ethers.getContractFactory("Whitelist", deployer);
@@ -144,6 +145,7 @@ describe("L1BlockContainer", async () => {
           test.parentHash,
           test.blockHeight - 1,
           test.blockTimestamp - 1,
+          test.baseFee,
           test.stateRoot
         );
         const headerRLP = encodeHeader(test);
@@ -158,6 +160,7 @@ describe("L1BlockContainer", async () => {
           test.parentHash,
           test.blockHeight - 1,
           test.blockTimestamp - 1,
+          test.baseFee,
           test.stateRoot
         );
         const headerRLP = encodeHeader(test);
@@ -172,6 +175,7 @@ describe("L1BlockContainer", async () => {
           constants.HashZero,
           test.blockHeight - 1,
           test.blockTimestamp - 1,
+          test.baseFee,
           test.stateRoot
         );
         const headerRLP = encodeHeader(test);
@@ -184,6 +188,7 @@ describe("L1BlockContainer", async () => {
           test.parentHash,
           test.blockHeight,
           test.blockTimestamp - 1,
+          test.baseFee,
           test.stateRoot
         );
         const headerRLP = encodeHeader(test);
@@ -196,6 +201,7 @@ describe("L1BlockContainer", async () => {
           test.parentHash,
           test.blockHeight - 1,
           test.blockTimestamp + 1,
+          test.baseFee,
           test.stateRoot
         );
         const headerRLP = encodeHeader(test);
@@ -210,16 +216,20 @@ describe("L1BlockContainer", async () => {
           test.parentHash,
           test.blockHeight - 1,
           test.blockTimestamp - 1,
+          test.baseFee,
           test.stateRoot
         );
         expect(await container.latestBlockHash()).to.eq(test.parentHash);
         const headerRLP = encodeHeader(test);
         await expect(container.importBlockHeader(test.hash, headerRLP, "0x"))
           .to.emit(container, "ImportBlock")
-          .withArgs(test.hash, test.blockHeight, test.blockTimestamp, test.stateRoot);
+          .withArgs(test.hash, test.blockHeight, test.blockTimestamp, test.baseFee, test.stateRoot);
         expect(await container.getStateRoot(test.hash)).to.eq(test.stateRoot);
         expect(await container.getBlockTimestamp(test.hash)).to.eq(test.blockTimestamp);
         expect(await container.latestBlockHash()).to.eq(test.hash);
+        expect(await container.latestBaseFee()).to.eq(test.baseFee);
+        expect(await container.latestBlockNumber()).to.eq(test.blockHeight);
+        expect(await container.latestBlockTimestamp()).to.eq(test.blockTimestamp);
       });
     });
   }
@@ -238,7 +248,14 @@ describe("L1BlockContainer", async () => {
       await container.deployed();
 
       const block = await ethers.provider.getBlock("latest");
-      await container.initialize(deployer.address, block.hash, block.number, block.timestamp, block.hash);
+      await container.initialize(
+        deployer.address,
+        block.hash,
+        block.number,
+        block.timestamp,
+        block.baseFeePerGas!,
+        block.hash
+      );
     });
 
     it("should revert, when block not imported", async () => {

contracts/src/L1/L1ScrollMessenger.sol

@@ -8,6 +8,7 @@ import { PausableUpgradeable } from "@openzeppelin/contracts-upgradeable/securit
 import { IZKRollup } from "./rollup/IZKRollup.sol";
 import { L1MessageQueue } from "./rollup/L1MessageQueue.sol";
 import { IL1ScrollMessenger, IScrollMessenger } from "./IL1ScrollMessenger.sol";
+import { Version } from "../libraries/common/Version.sol";
 import { IGasOracle } from "../libraries/oracle/IGasOracle.sol";
 import { ScrollConstants } from "../libraries/ScrollConstants.sol";
 import { ScrollMessengerBase } from "../libraries/ScrollMessengerBase.sol";
@@ -23,7 +24,7 @@ import { ZkTrieVerifier } from "../libraries/verifier/ZkTrieVerifier.sol";
 ///
 /// @dev All deposited Ether (including `WETH` deposited throng `L1WETHGateway`) will locked in
 /// this contract.
-contract L1ScrollMessenger is OwnableUpgradeable, PausableUpgradeable, ScrollMessengerBase, IL1ScrollMessenger {
+contract L1ScrollMessenger is Version, OwnableUpgradeable, PausableUpgradeable, ScrollMessengerBase, IL1ScrollMessenger {
   /*************
    * Variables *
    *************/

contracts/src/L1/gateways/L1CustomERC20Gateway.sol

@@ -9,6 +9,7 @@ import { SafeERC20Upgradeable } from "@openzeppelin/contracts-upgradeable/token/
 import { IL1ERC20Gateway, L1ERC20Gateway } from "./L1ERC20Gateway.sol";
 import { IL1ScrollMessenger } from "../IL1ScrollMessenger.sol";
 import { IL2ERC20Gateway } from "../../L2/gateways/IL2ERC20Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/ScrollGatewayBase.sol";
 
 /// @title L1CustomERC20Gateway
@@ -16,7 +17,7 @@ import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/Scrol
 /// finalize withdraw the tokens from layer 2.
 /// @dev The deposited tokens are held in this gateway. On finalizing withdraw, the corresponding
 /// tokens will be transfer to the recipient directly.
-contract L1CustomERC20Gateway is OwnableUpgradeable, ScrollGatewayBase, L1ERC20Gateway {
+contract L1CustomERC20Gateway is Version, OwnableUpgradeable, ScrollGatewayBase, L1ERC20Gateway {
   using SafeERC20Upgradeable for IERC20Upgradeable;
 
   /**************************************** Events ****************************************/

contracts/src/L1/gateways/L1ERC1155Gateway.sol

@@ -9,6 +9,7 @@ import { ERC1155HolderUpgradeable } from "@openzeppelin/contracts-upgradeable/to
 import { IL1ERC1155Gateway } from "./IL1ERC1155Gateway.sol";
 import { IL1ScrollMessenger } from "../IL1ScrollMessenger.sol";
 import { IL2ERC1155Gateway } from "../../L2/gateways/IL2ERC1155Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/ScrollGatewayBase.sol";
 
 /// @title L1ERC1155Gateway
@@ -19,7 +20,7 @@ import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/Scrol
 ///
 /// This will be changed if we have more specific scenarios.
 // @todo Current implementation doesn't support calling from `L1GatewayRouter`.
-contract L1ERC1155Gateway is OwnableUpgradeable, ERC1155HolderUpgradeable, ScrollGatewayBase, IL1ERC1155Gateway {
+contract L1ERC1155Gateway is Version, OwnableUpgradeable, ERC1155HolderUpgradeable, ScrollGatewayBase, IL1ERC1155Gateway {
   /**************************************** Events ****************************************/
 
   /// @notice Emitted when token mapping for ERC1155 token is updated.

contracts/src/L1/gateways/L1ERC20Gateway.sol

@@ -2,11 +2,13 @@
 
 pragma solidity ^0.8.0;
 
+import { Version } from "../../libraries/common/Version.sol";
+
 import { IL1ERC20Gateway } from "./IL1ERC20Gateway.sol";
 
 // solhint-disable no-empty-blocks
 
-abstract contract L1ERC20Gateway is IL1ERC20Gateway {
+abstract contract L1ERC20Gateway is Version, IL1ERC20Gateway {
   /// @inheritdoc IL1ERC20Gateway
   function depositERC20(
     address _token,

contracts/src/L1/gateways/L1ERC721Gateway.sol

@@ -9,6 +9,7 @@ import { ERC721HolderUpgradeable } from "@openzeppelin/contracts-upgradeable/tok
 import { IL1ERC721Gateway } from "./IL1ERC721Gateway.sol";
 import { IL1ScrollMessenger } from "../IL1ScrollMessenger.sol";
 import { IL2ERC721Gateway } from "../../L2/gateways/IL2ERC721Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/ScrollGatewayBase.sol";
 
 /// @title L1ERC721Gateway
@@ -19,7 +20,7 @@ import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/Scrol
 ///
 /// This will be changed if we have more specific scenarios.
 // @todo Current implementation doesn't support calling from `L1GatewayRouter`.
-contract L1ERC721Gateway is OwnableUpgradeable, ERC721HolderUpgradeable, ScrollGatewayBase, IL1ERC721Gateway {
+contract L1ERC721Gateway is Version, OwnableUpgradeable, ERC721HolderUpgradeable, ScrollGatewayBase, IL1ERC721Gateway {
   /**************************************** Events ****************************************/
 
   /// @notice Emitted when token mapping for ERC721 token is updated.

contracts/src/L1/gateways/L1GatewayRouter.sol

@@ -8,6 +8,7 @@ import { IL1GatewayRouter } from "./IL1GatewayRouter.sol";
 import { IL1ERC20Gateway } from "./IL1ERC20Gateway.sol";
 import { IL1ScrollMessenger } from "../IL1ScrollMessenger.sol";
 import { IL2GatewayRouter } from "../../L2/gateways/IL2GatewayRouter.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { IScrollGateway } from "../../libraries/gateway/IScrollGateway.sol";
 import { ScrollGatewayBase } from "../../libraries/gateway/ScrollGatewayBase.sol";
 
@@ -16,7 +17,7 @@ import { ScrollGatewayBase } from "../../libraries/gateway/ScrollGatewayBase.sol
 /// All deposited tokens are routed to corresponding gateways.
 /// @dev One can also use this contract to query L1/L2 token address mapping.
 /// In the future, ERC-721 and ERC-1155 tokens will be added to the router too.
-contract L1GatewayRouter is OwnableUpgradeable, ScrollGatewayBase, IL1GatewayRouter {
+contract L1GatewayRouter is Version, OwnableUpgradeable, ScrollGatewayBase, IL1GatewayRouter {
   /**************************************** Events ****************************************/
 
   event SetDefaultERC20Gateway(address indexed _defaultERC20Gateway);

contracts/src/L1/gateways/L1StandardERC20Gateway.sol

@@ -11,6 +11,7 @@ import { L1ERC20Gateway, IL1ERC20Gateway } from "./L1ERC20Gateway.sol";
 import { IL1ScrollMessenger } from "../IL1ScrollMessenger.sol";
 import { IERC20Metadata } from "../../interfaces/IERC20Metadata.sol";
 import { IL2ERC20Gateway } from "../../L2/gateways/IL2ERC20Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/ScrollGatewayBase.sol";
 
 /// @title L1StandardERC20Gateway
@@ -19,7 +20,7 @@ import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/Scrol
 /// @dev The deposited ERC20 tokens are held in this gateway. On finalizing withdraw, the corresponding
 /// token will be transfer to the recipient directly. Any ERC20 that requires non-standard functionality
 /// should use a separate gateway.
-contract L1StandardERC20Gateway is Initializable, ScrollGatewayBase, L1ERC20Gateway {
+contract L1StandardERC20Gateway is Version, Initializable, ScrollGatewayBase, L1ERC20Gateway {
   using SafeERC20 for IERC20;
 
   /**************************************** Variables ****************************************/

contracts/src/L1/gateways/L1WETHGateway.sol

@@ -10,6 +10,7 @@ import { L1ERC20Gateway, IL1ERC20Gateway } from "./L1ERC20Gateway.sol";
 import { IL1ScrollMessenger } from "../IL1ScrollMessenger.sol";
 import { IWETH } from "../../interfaces/IWETH.sol";
 import { IL2ERC20Gateway } from "../../L2/gateways/IL2ERC20Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/ScrollGatewayBase.sol";
 
 /// @title L1WETHGateway
@@ -19,7 +20,7 @@ import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/Scrol
 /// as Ether and then the Ether will be sent to the `L1ScrollMessenger` contract.
 /// On finalizing withdraw, the Ether will be transfered from `L1ScrollMessenger`, then
 /// wrapped as WETH and finally transfer to recipient.
-contract L1WETHGateway is Initializable, ScrollGatewayBase, L1ERC20Gateway {
+contract L1WETHGateway is Version, Initializable, ScrollGatewayBase, L1ERC20Gateway {
   using SafeERC20 for IERC20;
 
   /**************************************** Variables ****************************************/

contracts/src/L1/rollup/L1MessageQueue.sol

@@ -2,12 +2,13 @@
 
 pragma solidity ^0.8.0;
 
+import { Version } from "../../libraries/common/Version.sol";
 import { IL1MessageQueue } from "./IL1MessageQueue.sol";
 
 /// @title L1MessageQueue
 /// @notice This contract will hold all L1 to L2 messages.
 /// Each appended message is assigned with a unique and increasing `uint256` index denoting the message nonce.
-contract L1MessageQueue is IL1MessageQueue {
+contract L1MessageQueue is Version, IL1MessageQueue {
   /*************
    * Constants *
    *************/

contracts/src/L1/rollup/ZKRollup.sol

@@ -5,6 +5,7 @@ pragma solidity ^0.8.0;
 import { OwnableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
 
 import { IZKRollup } from "./IZKRollup.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { RollupVerifier } from "../../libraries/verifier/RollupVerifier.sol";
 
 // solhint-disable reason-string
@@ -16,7 +17,7 @@ import { RollupVerifier } from "../../libraries/verifier/RollupVerifier.sol";
 /// 2. the block tree generated by layer 2 and it's status.
 ///
 /// @dev the message queue is not used yet, the offline relayer only use events in `L1ScrollMessenger`.
-contract ZKRollup is OwnableUpgradeable, IZKRollup {
+contract ZKRollup is Version, OwnableUpgradeable, IZKRollup {
   /**********
    * Events *
    **********/

contracts/src/L2/L2ScrollMessenger.sol

@@ -6,6 +6,7 @@ import { IL2ScrollMessenger, IScrollMessenger } from "./IL2ScrollMessenger.sol";
 import { L2MessageQueue } from "./predeploys/L2MessageQueue.sol";
 import { IL1BlockContainer } from "./predeploys/IL1BlockContainer.sol";
 import { OwnableBase } from "../libraries/common/OwnableBase.sol";
+import { Version } from "../libraries/common/Version.sol";
 import { IGasOracle } from "../libraries/oracle/IGasOracle.sol";
 import { ScrollConstants } from "../libraries/ScrollConstants.sol";
 import { ScrollMessengerBase } from "../libraries/ScrollMessengerBase.sol";
@@ -19,7 +20,7 @@ import { ScrollMessengerBase } from "../libraries/ScrollMessengerBase.sol";
 ///
 /// @dev It should be a predeployed contract in layer 2 and should hold infinite amount
 /// of Ether (Specifically, `uint256(-1)`), which can be initialized in Genesis Block.
-contract L2ScrollMessenger is ScrollMessengerBase, OwnableBase, IL2ScrollMessenger {
+contract L2ScrollMessenger is Version, ScrollMessengerBase, OwnableBase, IL2ScrollMessenger {
   /**************************************** Variables ****************************************/
 
   /// @notice Mapping from relay id to relay status.
@@ -36,7 +37,7 @@ contract L2ScrollMessenger is ScrollMessengerBase, OwnableBase, IL2ScrollMesseng
 
   constructor(address _owner) {
     ScrollMessengerBase._initialize();
-    owner = _owner;
+    _transferOwnership(_owner);
 
     // initialize to a nonzero value
     xDomainMessageSender = ScrollConstants.DEFAULT_XDOMAIN_MESSAGE_SENDER;

contracts/src/L2/gateways/L2CustomERC20Gateway.sol

@@ -8,6 +8,7 @@ import { IERC20Upgradeable } from "@openzeppelin/contracts-upgradeable/token/ERC
 import { IL2ERC20Gateway, L2ERC20Gateway } from "./L2ERC20Gateway.sol";
 import { IL2ScrollMessenger } from "../IL2ScrollMessenger.sol";
 import { IL1ERC20Gateway } from "../../L1/gateways/IL1ERC20Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/ScrollGatewayBase.sol";
 import { IScrollStandardERC20 } from "../../libraries/token/IScrollStandardERC20.sol";
 
@@ -16,7 +17,7 @@ import { IScrollStandardERC20 } from "../../libraries/token/IScrollStandardERC20
 /// finalize deposit the tokens from layer 1.
 /// @dev The withdrawn tokens tokens will be burned directly. On finalizing deposit, the corresponding
 /// tokens will be minted and transfered to the recipient.
-contract L2CustomERC20Gateway is OwnableUpgradeable, ScrollGatewayBase, L2ERC20Gateway {
+contract L2CustomERC20Gateway is Version, OwnableUpgradeable, ScrollGatewayBase, L2ERC20Gateway {
   /**************************************** Events ****************************************/
 
   /// @notice Emitted when token mapping for ERC20 token is updated.

contracts/src/L2/gateways/L2ERC1155Gateway.sol

@@ -9,6 +9,7 @@ import { ERC1155HolderUpgradeable } from "@openzeppelin/contracts-upgradeable/to
 import { IL2ERC1155Gateway } from "./IL2ERC1155Gateway.sol";
 import { IL2ScrollMessenger } from "../IL2ScrollMessenger.sol";
 import { IL1ERC1155Gateway } from "../../L1/gateways/IL1ERC1155Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/ScrollGatewayBase.sol";
 import { IScrollERC1155 } from "../../libraries/token/IScrollERC1155.sol";
 
@@ -20,7 +21,7 @@ import { IScrollERC1155 } from "../../libraries/token/IScrollERC1155.sol";
 ///
 /// This will be changed if we have more specific scenarios.
 // @todo Current implementation doesn't support calling from `L2GatewayRouter`.
-contract L2ERC1155Gateway is OwnableUpgradeable, ERC1155HolderUpgradeable, ScrollGatewayBase, IL2ERC1155Gateway {
+contract L2ERC1155Gateway is Version, OwnableUpgradeable, ERC1155HolderUpgradeable, ScrollGatewayBase, IL2ERC1155Gateway {
   /**************************************** Events ****************************************/
 
   /// @notice Emitted when token mapping for ERC1155 token is updated.

contracts/src/L2/gateways/L2ERC20Gateway.sol

@@ -3,10 +3,11 @@
 pragma solidity ^0.8.0;
 
 import { IL2ERC20Gateway } from "./IL2ERC20Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 
 // solhint-disable no-empty-blocks
 
-abstract contract L2ERC20Gateway is IL2ERC20Gateway {
+abstract contract L2ERC20Gateway is Version, IL2ERC20Gateway {
   /// @inheritdoc IL2ERC20Gateway
   function withdrawERC20(
     address _token,

contracts/src/L2/gateways/L2ERC721Gateway.sol

@@ -9,6 +9,7 @@ import { ERC721HolderUpgradeable } from "@openzeppelin/contracts-upgradeable/tok
 import { IL2ERC721Gateway } from "./IL2ERC721Gateway.sol";
 import { IL2ScrollMessenger } from "../IL2ScrollMessenger.sol";
 import { IL1ERC721Gateway } from "../../L1/gateways/IL1ERC721Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/ScrollGatewayBase.sol";
 import { IScrollERC721 } from "../../libraries/token/IScrollERC721.sol";
 
@@ -20,7 +21,7 @@ import { IScrollERC721 } from "../../libraries/token/IScrollERC721.sol";
 ///
 /// This will be changed if we have more specific scenarios.
 // @todo Current implementation doesn't support calling from `L2GatewayRouter`.
-contract L2ERC721Gateway is OwnableUpgradeable, ERC721HolderUpgradeable, ScrollGatewayBase, IL2ERC721Gateway {
+contract L2ERC721Gateway is Version, OwnableUpgradeable, ERC721HolderUpgradeable, ScrollGatewayBase, IL2ERC721Gateway {
   /**************************************** Events ****************************************/
 
   /// @notice Emitted when token mapping for ERC721 token is updated.

contracts/src/L2/gateways/L2GatewayRouter.sol

@@ -8,6 +8,7 @@ import { IL2GatewayRouter } from "./IL2GatewayRouter.sol";
 import { IL2ERC20Gateway } from "./IL2ERC20Gateway.sol";
 import { IL2ScrollMessenger } from "../IL2ScrollMessenger.sol";
 import { IL1GatewayRouter } from "../../L1/gateways/IL1GatewayRouter.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { IScrollGateway } from "../../libraries/gateway/IScrollGateway.sol";
 import { ScrollGatewayBase } from "../../libraries/gateway/ScrollGatewayBase.sol";
 import { IScrollStandardERC20 } from "../../libraries/token/IScrollStandardERC20.sol";
@@ -17,7 +18,7 @@ import { IScrollStandardERC20 } from "../../libraries/token/IScrollStandardERC20
 /// All deposited tokens are routed to corresponding gateways.
 /// @dev One can also use this contract to query L1/L2 token address mapping.
 /// In the future, ERC-721 and ERC-1155 tokens will be added to the router too.
-contract L2GatewayRouter is OwnableUpgradeable, ScrollGatewayBase, IL2GatewayRouter {
+contract L2GatewayRouter is Version, OwnableUpgradeable, ScrollGatewayBase, IL2GatewayRouter {
   /**************************************** Events ****************************************/
 
   event SetDefaultERC20Gateway(address indexed _defaultERC20Gateway);

contracts/src/L2/gateways/L2StandardERC20Gateway.sol

@@ -10,6 +10,7 @@ import { Address } from "@openzeppelin/contracts/utils/Address.sol";
 import { IL2ERC20Gateway, L2ERC20Gateway } from "./L2ERC20Gateway.sol";
 import { IL2ScrollMessenger } from "../IL2ScrollMessenger.sol";
 import { IL1ERC20Gateway } from "../../L1/gateways/IL1ERC20Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { IScrollStandardERC20 } from "../../libraries/token/IScrollStandardERC20.sol";
 import { ScrollStandardERC20 } from "../../libraries/token/ScrollStandardERC20.sol";
 import { IScrollStandardERC20Factory } from "../../libraries/token/IScrollStandardERC20Factory.sol";
@@ -21,7 +22,7 @@ import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/Scrol
 /// @dev The withdrawn ERC20 tokens will be burned directly. On finalizing deposit, the corresponding
 /// token will be minted and transfered to the recipient. Any ERC20 that requires non-standard functionality
 /// should use a separate gateway.
-contract L2StandardERC20Gateway is Initializable, ScrollGatewayBase, L2ERC20Gateway {
+contract L2StandardERC20Gateway is Version, Initializable, ScrollGatewayBase, L2ERC20Gateway {
   using SafeERC20 for IERC20;
   using Address for address;
 

contracts/src/L2/gateways/L2WETHGateway.sol

@@ -10,6 +10,7 @@ import { IL2ERC20Gateway, L2ERC20Gateway } from "./L2ERC20Gateway.sol";
 import { IL2ScrollMessenger } from "../IL2ScrollMessenger.sol";
 import { IWETH } from "../../interfaces/IWETH.sol";
 import { IL1ERC20Gateway } from "../../L1/gateways/IL1ERC20Gateway.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/ScrollGatewayBase.sol";
 
 /// @title L2WETHGateway
@@ -19,7 +20,7 @@ import { ScrollGatewayBase, IScrollGateway } from "../../libraries/gateway/Scrol
 /// then the Ether will be sent to the `L2ScrollMessenger` contract.
 /// On finalizing deposit, the Ether will be transfered from `L2ScrollMessenger`, then
 /// wrapped as WETH and finally transfer to recipient.
-contract L2WETHGateway is Initializable, ScrollGatewayBase, L2ERC20Gateway {
+contract L2WETHGateway is Version, Initializable, ScrollGatewayBase, L2ERC20Gateway {
   using SafeERC20 for IERC20;
 
   /**************************************** Variables ****************************************/

contracts/src/L2/predeploys/IL1BlockContainer.sol

@@ -11,27 +11,26 @@ interface IL1BlockContainer {
   /// @param blockHash The hash of the imported block.
   /// @param blockHeight The height of the imported block.
   /// @param blockTimestamp The timestamp of the imported block.
+  /// @param baseFee The base fee of the imported block.
   /// @param stateRoot The state root of the imported block.
-  event ImportBlock(bytes32 indexed blockHash, uint256 blockHeight, uint256 blockTimestamp, bytes32 stateRoot);
-
-  /***********
-   * Structs *
-   ***********/
-
-  /// @dev Compiler will pack this into single `uint256`.
-  struct BlockMetadata {
-    // The block height.
-    uint64 height;
-    // The block timestamp.
-    uint64 timestamp;
-    // The reserved field.
-    uint128 reserved;
-  }
+  event ImportBlock(bytes32 indexed blockHash, uint256 blockHeight, uint256 blockTimestamp, uint256 baseFee, bytes32 stateRoot);
 
   /*************************
    * Public View Functions *
    *************************/
 
+  /// @notice Return the latest imported block hash
+  function latestBlockHash() external view returns (bytes32);
+
+  /// @notice Return the latest imported L1 base fee
+  function latestBaseFee() external view returns (uint256);
+
+  /// @notice Return the latest imported block number
+  function latestBlockNumber() external view returns (uint256);
+
+  /// @notice Return the latest imported block timestamp
+  function latestBlockTimestamp() external view returns (uint256);
+
   /// @notice Check whether the message is included in the corresponding L1 block.
   /// @param blockHash The block hash where the message should in.
   /// @param msgHash The hash of the message to check.

contracts/src/L2/predeploys/IL2GasPriceOracle.sol

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+interface IL2GasPriceOracle {
+  /**********
+   * Events *
+   **********/
+
+  /// @notice Emitted when current fee overhead is updated.
+  /// @param overhead The current fee overhead updated.
+  event OverheadUpdated(uint256 overhead);
+
+  /// @notice Emitted when current fee scalar is updated.
+  /// @param scalar The current fee scalar updated.
+  event ScalarUpdated(uint256 scalar);
+
+  /*************************
+   * Public View Functions *
+   *************************/
+
+  /// @notice Return the current L2 base fee.
+  function baseFee() external view returns (uint256);
+
+  /// @notice Return the current L2 gas price (base fee).
+  function gasPrice() external view returns (uint256);
+
+  /// @notice Return the current l1 fee overhead.
+  function overhead() external view returns (uint256);
+
+  /// @notice Return the current l1 fee scalar.
+  function scalar() external view returns (uint256);
+
+  /// @notice Return the latest known l1 base fee.
+  function l1BaseFee() external view returns (uint256);
+
+  /// @notice Computes the L1 portion of the fee based on the size of the rlp encoded input
+  ///         transaction, the current L1 base fee, and the various dynamic parameters.
+  /// @param data Unsigned fully RLP-encoded transaction to get the L1 fee for.
+  /// @return L1 fee that should be paid for the tx
+  function getL1Fee(bytes memory data) external view returns (uint256);
+
+  /// @notice Computes the amount of L1 gas used for a transaction. Adds the overhead which
+  ///         represents the per-transaction gas overhead of posting the transaction and state
+  ///         roots to L1. Adds 68 bytes of padding to account for the fact that the input does
+  ///         not have a signature.
+  /// @param data Unsigned fully RLP-encoded transaction to get the L1 gas for.
+  /// @return Amount of L1 gas used to publish the transaction.
+  function getL1GasUsed(bytes memory data) external view returns (uint256);
+}

contracts/src/L2/predeploys/L1BlockContainer.sol

@@ -8,11 +8,12 @@ import { IL1BlockContainer } from "./IL1BlockContainer.sol";
 
 import { OwnableBase } from "../../libraries/common/OwnableBase.sol";
 import { IWhitelist } from "../../libraries/common/IWhitelist.sol";
+import { Version } from "../../libraries/common/Version.sol";
 import { PatriciaMerkleTrieVerifier } from "../../libraries/verifier/PatriciaMerkleTrieVerifier.sol";
 
 /// @title L1BlockContainer
 /// @notice This contract will maintain the list of blocks proposed in L1.
-contract L1BlockContainer is Initializable, OwnableBase, IL1BlockContainer {
+contract L1BlockContainer is Version, Initializable, OwnableBase, IL1BlockContainer {
   /**********
    * Events *
    **********/
@@ -32,6 +33,20 @@ contract L1BlockContainer is Initializable, OwnableBase, IL1BlockContainer {
   /// @notice The address of L1ScrollMessenger contract.
   address public immutable messenger;
 
+  /***********
+   * Structs *
+   ***********/
+
+  /// @dev Compiler will pack this into single `uint256`.
+  struct BlockMetadata {
+    // The block height.
+    uint64 height;
+    // The block timestamp.
+    uint64 timestamp;
+    // The base fee in the block.
+    uint128 baseFee;
+  }
+
   /*************
    * Variables *
    *************/
@@ -41,8 +56,8 @@ contract L1BlockContainer is Initializable, OwnableBase, IL1BlockContainer {
 
   // @todo change to ring buffer to save gas usage.
 
-  /// @notice The hash of last imported block.
-  bytes32 public latestBlockHash;
+  /// @inheritdoc IL1BlockContainer
+  bytes32 public override latestBlockHash;
 
   /// @notice Mapping from block hash to corresponding state root.
   mapping(bytes32 => bytes32) public stateRoot;
@@ -65,21 +80,37 @@ contract L1BlockContainer is Initializable, OwnableBase, IL1BlockContainer {
     bytes32 _startBlockHash,
     uint64 _startBlockHeight,
     uint64 _startBlockTimestamp,
+    uint128 _startBlockBaseFee,
     bytes32 _startStateRoot
   ) public initializer {
-    owner = _owner;
+    _transferOwnership(_owner);
 
     latestBlockHash = _startBlockHash;
     stateRoot[_startBlockHash] = _startStateRoot;
-    metadata[_startBlockHash] = BlockMetadata(_startBlockHeight, _startBlockTimestamp, 0);
+    metadata[_startBlockHash] = BlockMetadata(_startBlockHeight, _startBlockTimestamp, _startBlockBaseFee);
 
-    emit ImportBlock(_startBlockHash, _startBlockHeight, _startBlockTimestamp, _startStateRoot);
+    emit ImportBlock(_startBlockHash, _startBlockHeight, _startBlockTimestamp, _startBlockBaseFee, _startStateRoot);
   }
 
   /*************************
    * Public View Functions *
    *************************/
 
+  /// @inheritdoc IL1BlockContainer
+  function latestBaseFee() external override view returns (uint256) {
+    return metadata[latestBlockHash].baseFee;
+  }
+
+  /// @inheritdoc IL1BlockContainer
+  function latestBlockNumber() external override view returns (uint256) {
+    return metadata[latestBlockHash].height;
+  }
+
+  /// @inheritdoc IL1BlockContainer
+  function latestBlockTimestamp() external override view returns (uint256) {
+    return metadata[latestBlockHash].timestamp;
+  }
+
   /// @inheritdoc IL1BlockContainer
   function verifyMessageInclusionStatus(
     bytes32 _blockHash,
@@ -181,6 +212,7 @@ contract L1BlockContainer is Initializable, OwnableBase, IL1BlockContainer {
     bytes32 _stateRoot;
     uint64 _height;
     uint64 _timestamp;
+    uint128 _baseFee;
 
     assembly {
       // reverts with error `msg`.
@@ -304,6 +336,8 @@ contract L1BlockContainer is Initializable, OwnableBase, IL1BlockContainer {
       _height := mload(add(memPtr, 0x100))
       // load block timestamp, 12-th entry
       _timestamp := mload(add(memPtr, 0x160))
+      // load base fee, 16-th entry
+      _baseFee := mload(add(memPtr, 0x1e0))
     }
     require(stateRoot[_parentHash] != bytes32(0), "Parent not imported");
     BlockMetadata memory _parentMetadata = metadata[_parentHash];
@@ -312,9 +346,9 @@ contract L1BlockContainer is Initializable, OwnableBase, IL1BlockContainer {
 
     latestBlockHash = _blockHash;
     stateRoot[_blockHash] = _stateRoot;
-    metadata[_blockHash] = BlockMetadata(_height, _timestamp, 0);
+    metadata[_blockHash] = BlockMetadata(_height, _timestamp, _baseFee);
 
-    emit ImportBlock(_blockHash, _height, _timestamp, _stateRoot);
+    emit ImportBlock(_blockHash, _height, _timestamp, _baseFee, _stateRoot);
   }
 
   /************************

contracts/src/L2/predeploys/L2GasPriceOracle.sol

@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import { OwnableBase } from "../../libraries/common/OwnableBase.sol";
+import { Version } from "../../libraries/common/Version.sol";
+
+import "./IL1BlockContainer.sol";
+import "./IL2GasPriceOracle.sol";
+
+contract L2GasPriceOracle is Version, OwnableBase, IL2GasPriceOracle {
+  /*************
+   * Constants *
+   *************/
+
+  /// @dev The precision used in the scalar.
+  uint256 private constant PRECISION = 1e9;
+
+  /// @dev The maximum possible l1 fee overhead.
+  ///      Computed based on current l1 block gas limit.
+  uint256 private constant MAX_OVERHEAD = 30000000/16;
+
+  /// @dev The maximum possible l1 fee scale.
+  ///      x1000 should be enough.
+  uint256 private constant MAX_SCALE = 1000 * PRECISION;
+
+  /// @notice The address of L1BlockContainer contract.
+  address public immutable blockContainer;
+
+  /*************
+   * Variables *
+   *************/
+
+  /// @inheritdoc IL2GasPriceOracle
+  uint256 public override overhead;
+
+  /// @inheritdoc IL2GasPriceOracle
+  uint256 public override scalar;
+
+  /***************
+   * Constructor *
+   ***************/
+
+  constructor(address _owner, address _blockContainer) {
+    _transferOwnership(_owner);
+
+    blockContainer = _blockContainer;
+  }
+
+  /*************************
+   * Public View Functions *
+   *************************/
+
+  /// @inheritdoc IL2GasPriceOracle
+  function baseFee() external view override returns (uint256) {
+    return block.basefee;
+  }
+
+  /// @inheritdoc IL2GasPriceOracle
+  function gasPrice() external view override returns (uint256) {
+    return block.basefee;
+  }
+
+  /// @notice Return the latest known l1 base fee.
+  function l1BaseFee() public view override returns (uint256) {
+    return IL1BlockContainer(blockContainer).latestBaseFee();
+  }
+
+  /// @inheritdoc IL2GasPriceOracle
+  function getL1Fee(bytes memory _data) external view override returns (uint256) {
+    unchecked {
+      uint256 _l1GasUsed = getL1GasUsed(_data);
+      uint256 _l1Fee = _l1GasUsed * l1BaseFee();
+      return (_l1Fee * scalar) / PRECISION;
+    }
+  }
+
+  /// @inheritdoc IL2GasPriceOracle
+  /// @dev See the comments in `OVM_GasPriceOracle1` for more details
+  ///      https://github.com/ethereum-optimism/optimism/blob/develop/packages/contracts/contracts/L2/predeploys/OVM_GasPriceOracle.sol
+  function getL1GasUsed(bytes memory _data) public view override returns (uint256) {
+    uint256 _total = 0;
+    uint256 _length = _data.length;
+    unchecked {
+      for (uint256 i = 0; i < _length; i++) {
+        if (_data[i] == 0) {
+          _total += 4;
+        } else {
+          _total += 16;
+        }
+      }
+      uint256 _unsigned = _total + overhead;
+      return _unsigned + (68 * 16);
+    }
+  }
+
+  /************************
+   * Restricted Functions *
+   ************************/
+
+  /// @notice Allows the owner to modify the overhead.
+  /// @param _overhead New overhead
+  function setOverhead(uint256 _overhead) external onlyOwner {
+    require(_overhead <= MAX_OVERHEAD, "exceed maximum overhead");
+
+    overhead = _overhead;
+    emit OverheadUpdated(_overhead);
+  }
+
+  /// Allows the owner to modify the scalar.
+  /// @param _scalar New scalar
+  function setScalar(uint256 _scalar) external onlyOwner {
+    require(_scalar <= MAX_SCALE, "exceed maximum scale");
+
+    scalar = _scalar;
+    emit ScalarUpdated(_scalar);
+  }
+}

contracts/src/L2/predeploys/L2MessageQueue.sol

@@ -3,6 +3,7 @@
 pragma solidity ^0.8.0;
 
 import { AppendOnlyMerkleTree } from "../../libraries/common/AppendOnlyMerkleTree.sol";
+import { Version } from "../../libraries/common/Version.sol";
 
 /// @title L2MessageQueue
 /// @notice The original idea is from Optimism, see [OVM_L2ToL1MessagePasser](https://github.com/ethereum-optimism/optimism/blob/develop/packages/contracts/contracts/L2/predeploys/OVM_L2ToL1MessagePasser.sol).
@@ -10,7 +11,7 @@ import { AppendOnlyMerkleTree } from "../../libraries/common/AppendOnlyMerkleTre
 /// of a message on L2. The L1 Cross Domain Messenger performs this proof in its
 /// _verifyStorageProof function, which verifies the existence of the transaction hash in this
 /// contract's `sentMessages` mapping.
-contract L2MessageQueue is AppendOnlyMerkleTree {
+contract L2MessageQueue is Version, AppendOnlyMerkleTree {
   /// @notice Emitted when a new message is added to the merkle tree.
   /// @param index The index of the corresponding message.
   /// @param messageHash The hash of the corresponding message.

contracts/src/libraries/common/Version.sol

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+abstract contract Version {
+  /// @notice the current contract version.
+  string public constant version = "0.0.1";
+}

contracts/src/test/L2GasPriceOracle.t.sol

@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import { DSTestPlus } from "solmate/test/utils/DSTestPlus.sol";
+import { WETH } from "solmate/tokens/WETH.sol";
+
+import { L1BlockContainer } from "../L2/predeploys/L1BlockContainer.sol";
+import { L2GasPriceOracle } from "../L2/predeploys/L2GasPriceOracle.sol";
+
+contract L2GasPriceOracleTest is DSTestPlus {
+  uint256 private constant PRECISION = 1e9;
+  uint256 private constant MAX_OVERHEAD = 30000000 / 16;
+  uint256 private constant MAX_SCALE = 1000 * PRECISION;
+
+  L2GasPriceOracle private oracle;
+  L1BlockContainer private container;
+
+  function setUp() public {
+    container = new L1BlockContainer(address(0), address(0));
+    oracle = new L2GasPriceOracle(address(this), address(container));
+  }
+
+  function testSetOverhead(uint256 _overhead) external {
+    _overhead = bound(_overhead, 0, MAX_OVERHEAD);
+
+    // call by non-owner, should revert
+    hevm.startPrank(address(1));
+    hevm.expectRevert("caller is not the owner");
+    oracle.setOverhead(_overhead);
+    hevm.stopPrank();
+
+    // overhead is too large
+    hevm.expectRevert("exceed maximum overhead");
+    oracle.setOverhead(MAX_OVERHEAD + 1);
+
+    // call by owner, should succeed
+    assertEq(oracle.overhead(), 0);
+    oracle.setOverhead(_overhead);
+    assertEq(oracle.overhead(), _overhead);
+  }
+
+  function testSetScalar(uint256 _scalar) external {
+    _scalar = bound(_scalar, 0, MAX_SCALE);
+
+    // call by non-owner, should revert
+    hevm.startPrank(address(1));
+    hevm.expectRevert("caller is not the owner");
+    oracle.setScalar(_scalar);
+    hevm.stopPrank();
+
+    // scale is too large
+    hevm.expectRevert("exceed maximum scale");
+    oracle.setScalar(MAX_SCALE + 1);
+
+    // call by owner, should succeed
+    assertEq(oracle.scalar(), 0);
+    oracle.setScalar(_scalar);
+    assertEq(oracle.scalar(), _scalar);
+  }
+
+  function testGetL1GasUsed(uint256 _overhead, bytes memory _data) external {
+    _overhead = bound(_overhead, 0, MAX_OVERHEAD);
+
+    oracle.setOverhead(_overhead);
+
+    uint256 _gasUsed = _overhead + 68 * 16;
+    for (uint256 i = 0; i < _data.length; i++) {
+      if (_data[i] == 0) _gasUsed += 4;
+      else _gasUsed += 16;
+    }
+
+    assertEq(oracle.getL1GasUsed(_data), _gasUsed);
+  }
+
+  function testGetL1Fee(
+    uint256 _baseFee,
+    uint256 _overhead,
+    uint256 _scalar,
+    bytes memory _data
+  ) external {
+    _overhead = bound(_overhead, 0, MAX_OVERHEAD);
+    _scalar = bound(_scalar, 0, MAX_SCALE);
+    _baseFee = bound(_baseFee, 0, 1e9 * 20000); // max 20k gwei
+
+    oracle.setOverhead(_overhead);
+    oracle.setScalar(_scalar);
+    container.initialize(address(0), bytes32(0), 0, 0, uint128(_baseFee), bytes32(0));
+
+    uint256 _gasUsed = _overhead + 68 * 16;
+    for (uint256 i = 0; i < _data.length; i++) {
+      if (_data[i] == 0) _gasUsed += 4;
+      else _gasUsed += 16;
+    }
+
+    assertEq(oracle.getL1Fee(_data), (_gasUsed * _baseFee * _scalar) / PRECISION);
+  }
+}