feat: pay out arbitrary fee to coinbase on L1 (AztecProtocol#6436)

Fix AztecProtocol#5007

Just some basic plumbing to allow us to pay out fees to coinbase.

l1-contracts/src/core/Rollup.sol

@@ -8,6 +8,7 @@ import {IAvailabilityOracle} from "./interfaces/IAvailabilityOracle.sol";
 import {IInbox} from "./interfaces/messagebridge/IInbox.sol";
 import {IOutbox} from "./interfaces/messagebridge/IOutbox.sol";
 import {IRegistry} from "./interfaces/messagebridge/IRegistry.sol";
+import {IERC20} from "@oz/token/ERC20/IERC20.sol";
 
 // Libraries
 import {HeaderLib} from "./libraries/HeaderLib.sol";
@@ -33,17 +34,19 @@ contract Rollup is IRollup {
   IInbox public immutable INBOX;
   IOutbox public immutable OUTBOX;
   uint256 public immutable VERSION;
+  IERC20 public immutable GAS_TOKEN;
 
   bytes32 public archive; // Root of the archive tree
   uint256 public lastBlockTs;
   // Tracks the last time time was warped on L2 ("warp" is the testing cheatcode).
   // See https://github.com/AztecProtocol/aztec-packages/issues/1614
   uint256 public lastWarpedBlockTs;
 
-  constructor(IRegistry _registry, IAvailabilityOracle _availabilityOracle) {
+  constructor(IRegistry _registry, IAvailabilityOracle _availabilityOracle, IERC20 _gasToken) {
     VERIFIER = new MockVerifier();
     REGISTRY = _registry;
     AVAILABILITY_ORACLE = _availabilityOracle;
+    GAS_TOKEN = _gasToken;
     INBOX = new Inbox(address(this), Constants.L1_TO_L2_MSG_SUBTREE_HEIGHT);
     OUTBOX = new Outbox(address(this));
     VERSION = 1;
@@ -92,6 +95,11 @@ contract Rollup is IRollup {
       header.globalVariables.blockNumber, header.contentCommitment.outHash, l2ToL1TreeHeight
     );
 
+    // pay the coinbase 1 gas token if it is not empty
+    if (header.globalVariables.coinbase != address(0)) {
+      GAS_TOKEN.transfer(address(header.globalVariables.coinbase), 1);
+    }
+
     emit L2BlockProcessed(header.globalVariables.blockNumber);
   }
 

l1-contracts/test/Rollup.t.sol

@@ -2,6 +2,8 @@
 // Copyright 2023 Aztec Labs.
 pragma solidity >=0.8.18;
 
+import {IERC20} from "@oz/token/ERC20/IERC20.sol";
+
 import {DecoderBase} from "./decoders/Base.sol";
 
 import {DataStructures} from "../src/core/libraries/DataStructures.sol";
@@ -15,6 +17,7 @@ import {Rollup} from "../src/core/Rollup.sol";
 import {AvailabilityOracle} from "../src/core/availability_oracle/AvailabilityOracle.sol";
 import {NaiveMerkle} from "./merkle/Naive.sol";
 import {MerkleTestUtil} from "./merkle/TestUtil.sol";
+import {PortalERC20} from "./portals/PortalERC20.sol";
 
 import {TxsDecoderHelper} from "./decoders/helpers/TxsDecoderHelper.sol";
 
@@ -29,18 +32,23 @@ contract RollupTest is DecoderBase {
   Rollup internal rollup;
   MerkleTestUtil internal merkleTestUtil;
   TxsDecoderHelper internal txsHelper;
+  PortalERC20 internal portalERC20;
 
   AvailabilityOracle internal availabilityOracle;
 
   function setUp() public virtual {
     registry = new Registry();
     availabilityOracle = new AvailabilityOracle();
-    rollup = new Rollup(registry, availabilityOracle);
+    portalERC20 = new PortalERC20();
+    rollup = new Rollup(registry, availabilityOracle, IERC20(address(portalERC20)));
     inbox = Inbox(address(rollup.INBOX()));
     outbox = Outbox(address(rollup.OUTBOX()));
 
     registry.upgrade(address(rollup), address(inbox), address(outbox));
 
+    // mint some tokens to the rollup
+    portalERC20.mint(address(rollup), 1000000);
+
     merkleTestUtil = new MerkleTestUtil();
     txsHelper = new TxsDecoderHelper();
   }

l1-contracts/test/portals/TokenPortal.t.sol

@@ -14,6 +14,7 @@ import {Errors} from "../../src/core/libraries/Errors.sol";
 // Interfaces
 import {IInbox} from "../../src/core/interfaces/messagebridge/IInbox.sol";
 import {IOutbox} from "../../src/core/interfaces/messagebridge/IOutbox.sol";
+import {IERC20} from "@oz/token/ERC20/IERC20.sol";
 
 // Portal tokens
 import {TokenPortal} from "./TokenPortal.sol";
@@ -57,13 +58,14 @@ contract TokenPortalTest is Test {
 
   function setUp() public {
     registry = new Registry();
-    rollup = new Rollup(registry, new AvailabilityOracle());
+    portalERC20 = new PortalERC20();
+    rollup = new Rollup(registry, new AvailabilityOracle(), IERC20(address(portalERC20)));
     inbox = rollup.INBOX();
     outbox = rollup.OUTBOX();
 
     registry.upgrade(address(rollup), address(inbox), address(outbox));
 
-    portalERC20 = new PortalERC20();
+    portalERC20.mint(address(rollup), 1000000);
     tokenPortal = new TokenPortal();
 
     tokenPortal.initialize(address(registry), address(portalERC20), l2TokenAddress);

l1-contracts/test/portals/UniswapPortal.t.sol

@@ -20,6 +20,9 @@ import {NaiveMerkle} from "../merkle/Naive.sol";
 import {TokenPortal} from "./TokenPortal.sol";
 import {UniswapPortal} from "./UniswapPortal.sol";
 
+// Portal tokens
+import {PortalERC20} from "./PortalERC20.sol";
+
 contract UniswapPortalTest is Test {
   using Hash for DataStructures.L2ToL1Msg;
 
@@ -48,8 +51,10 @@ contract UniswapPortalTest is Test {
     vm.selectFork(forkId);
 
     registry = new Registry();
-    rollup = new Rollup(registry, new AvailabilityOracle());
+    PortalERC20 portalERC20 = new PortalERC20();
+    rollup = new Rollup(registry, new AvailabilityOracle(), IERC20(address(portalERC20)));
     registry.upgrade(address(rollup), address(rollup.INBOX()), address(rollup.OUTBOX()));
+    portalERC20.mint(address(rollup), 1000000);
 
     daiTokenPortal = new TokenPortal();
     daiTokenPortal.initialize(address(registry), address(DAI), l2TokenAddress);

yarn-project/end-to-end/src/e2e_fees/fees_test.ts

@@ -14,8 +14,9 @@ import {
   createDebugLogger,
 } from '@aztec/aztec.js';
 import { DefaultMultiCallEntrypoint } from '@aztec/aztec.js/entrypoint';
-import { GasSettings } from '@aztec/circuits.js';
+import { EthAddress, GasSettings } from '@aztec/circuits.js';
 import { createL1Clients } from '@aztec/ethereum';
+import { PortalERC20Abi } from '@aztec/l1-artifacts';
 import {
   AppSubscriptionContract,
   TokenContract as BananaCoin,
@@ -24,6 +25,8 @@ import {
   GasTokenContract,
 } from '@aztec/noir-contracts.js';
 
+import { getContract } from 'viem';
+
 import { MNEMONIC } from '../fixtures/fixtures.js';
 import {
   type ISnapshotManager,
@@ -58,6 +61,7 @@ export class FeesTest {
   public bobWallet!: AccountWallet;
   public bobAddress!: AztecAddress;
   public sequencerAddress!: AztecAddress;
+  public coinbase!: EthAddress;
 
   public gasSettings = GasSettings.default();
   public maxFee = this.gasSettings.getFeeLimit().toBigInt();
@@ -68,6 +72,7 @@ export class FeesTest {
   public counterContract!: CounterContract;
   public subscriptionContract!: AppSubscriptionContract;
 
+  public getCoinbaseBalance!: () => Promise<bigint>;
   public gasBalances!: BalancesFn;
   public bananaPublicBalances!: BalancesFn;
   public bananaPrivateBalances!: BalancesFn;
@@ -84,7 +89,7 @@ export class FeesTest {
 
   async setup() {
     const context = await this.snapshotManager.setup();
-    await context.aztecNode.setConfig({ feeRecipient: this.sequencerAddress });
+    await context.aztecNode.setConfig({ feeRecipient: this.sequencerAddress, coinbase: this.coinbase });
     ({ pxe: this.pxe, aztecNode: this.aztecNode } = context);
     return this;
   }
@@ -138,6 +143,7 @@ export class FeesTest {
         this.wallets.forEach((w, i) => this.logger.verbose(`Wallet ${i} address: ${w.getAddress()}`));
         [this.aliceWallet, this.bobWallet] = this.wallets.slice(0, 2);
         [this.aliceAddress, this.bobAddress, this.sequencerAddress] = this.wallets.map(w => w.getAddress());
+        this.coinbase = EthAddress.random();
       },
     );
   }
@@ -185,6 +191,8 @@ export class FeesTest {
           bananaCoinAddress: bananaCoin.address,
           bananaFPCAddress: bananaFPC.address,
           gasTokenAddress: gasTokenContract.address,
+          l1GasTokenAddress: harness.l1GasTokenAddress,
+          rpcUrl: context.aztecNodeConfig.rpcUrl,
         };
       },
       async data => {
@@ -199,6 +207,16 @@ export class FeesTest {
         this.bananaPublicBalances = getBalancesFn('🍌.public', bananaCoin.methods.balance_of_public, this.logger);
         this.bananaPrivateBalances = getBalancesFn('🍌.private', bananaCoin.methods.balance_of_private, this.logger);
         this.gasBalances = getBalancesFn('⛽', gasTokenContract.methods.balance_of_public, this.logger);
+
+        this.getCoinbaseBalance = async () => {
+          const { walletClient } = createL1Clients(data.rpcUrl, MNEMONIC);
+          const gasL1 = getContract({
+            address: data.l1GasTokenAddress.toString(),
+            abi: PortalERC20Abi,
+            client: walletClient,
+          });
+          return await gasL1.read.balanceOf([this.coinbase.toString()]);
+        };
       },
     );
   }

yarn-project/end-to-end/src/e2e_fees/private_payments.test.ts

@@ -36,6 +36,8 @@ describe('e2e_fees private_payment', () => {
     await t.teardown();
   });
 
+  let InitialSequencerL1Gas: bigint;
+
   let InitialAlicePublicBananas: bigint;
   let InitialAlicePrivateBananas: bigint;
   let InitialAliceGas: bigint;
@@ -59,6 +61,8 @@ describe('e2e_fees private_payment', () => {
 
     expect(gasSettings.getFeeLimit().toBigInt()).toEqual(maxFee);
 
+    InitialSequencerL1Gas = await t.getCoinbaseBalance();
+
     [
       [InitialAlicePrivateBananas, InitialBobPrivateBananas, InitialFPCPrivateBananas],
       [InitialAlicePublicBananas, InitialBobPublicBananas, InitialFPCPublicBananas],
@@ -104,7 +108,6 @@ describe('e2e_fees private_payment', () => {
      */
     const transferAmount = 5n;
     const interaction = bananaCoin.methods.transfer(aliceAddress, bobAddress, transferAmount, 0n);
-
     const localTx = await interaction.prove({
       fee: {
         gasSettings,
@@ -115,6 +118,8 @@ describe('e2e_fees private_payment', () => {
 
     const tx = await interaction.send().wait();
 
+    await expect(t.getCoinbaseBalance()).resolves.toEqual(InitialSequencerL1Gas + 1n);
+
     /**
      * at present the user is paying DA gas for:
      * 3 nullifiers = 3 * DA_BYTES_PER_FIELD * DA_GAS_PER_BYTE = 3 * 32 * 16 = 1536 DA gas

yarn-project/end-to-end/src/shared/gas_portal_test_harness.ts

@@ -23,8 +23,10 @@ import {
 } from 'viem';
 
 export interface IGasBridgingTestHarness {
+  getL1GasTokenBalance(address: EthAddress): Promise<bigint>;
   bridgeFromL1ToL2(l1TokenBalance: bigint, bridgeAmount: bigint, owner: AztecAddress): Promise<void>;
   l2Token: GasTokenContract;
+  l1GasTokenAddress: EthAddress;
 }
 
 export interface GasPortalTestingHarnessFactoryConfig {
@@ -49,7 +51,7 @@ export class GasPortalTestingHarnessFactory {
         contractAddressSalt: getCanonicalGasToken(EthAddress.ZERO).instance.salt,
       })
       .deployed();
-    return Promise.resolve(new MockGasBridgingTestHarness(gasL2));
+    return Promise.resolve(new MockGasBridgingTestHarness(gasL2, EthAddress.ZERO));
   }
 
   private async createReal() {
@@ -111,10 +113,13 @@ export class GasPortalTestingHarnessFactory {
 }
 
 class MockGasBridgingTestHarness implements IGasBridgingTestHarness {
-  constructor(public l2Token: GasTokenContract) {}
+  constructor(public l2Token: GasTokenContract, public l1GasTokenAddress: EthAddress) {}
   async bridgeFromL1ToL2(_l1TokenBalance: bigint, bridgeAmount: bigint, owner: AztecAddress): Promise<void> {
     await this.l2Token.methods.mint_public(owner, bridgeAmount).send().wait();
   }
+  getL1GasTokenBalance(_address: EthAddress): Promise<bigint> {
+    throw new Error('Cannot get gas token balance on mocked L1.');
+  }
 }
 
 /**
@@ -150,6 +155,10 @@ class GasBridgingTestHarness implements IGasBridgingTestHarness {
     public walletClient: WalletClient,
   ) {}
 
+  get l1GasTokenAddress() {
+    return EthAddress.fromString(this.underlyingERC20.address);
+  }
+
   generateClaimSecret(): [Fr, Fr] {
     this.logger.debug("Generating a claim secret using pedersen's hash function");
     const secret = Fr.random();
@@ -166,7 +175,7 @@ class GasBridgingTestHarness implements IGasBridgingTestHarness {
     expect(await this.underlyingERC20.read.balanceOf([this.ethAccount.toString()])).toBe(amount);
   }
 
-  async getL1BalanceOf(address: EthAddress) {
+  async getL1GasTokenBalance(address: EthAddress) {
     return await this.underlyingERC20.read.balanceOf([address.toString()]);
   }
 
@@ -211,7 +220,7 @@ class GasBridgingTestHarness implements IGasBridgingTestHarness {
 
     // 2. Deposit tokens to the TokenPortal
     const msgHash = await this.sendTokensToPortalPublic(bridgeAmount, owner, secretHash);
-    expect(await this.getL1BalanceOf(this.ethAccount)).toBe(l1TokenBalance - bridgeAmount);
+    expect(await this.getL1GasTokenBalance(this.ethAccount)).toBe(l1TokenBalance - bridgeAmount);
 
     // Perform an unrelated transactions on L2 to progress the rollup by 2 blocks.
     await this.l2Token.methods.check_balance(0).send().wait();

yarn-project/ethereum/src/deploy_l1_contracts.ts

@@ -158,12 +158,25 @@ export const deployL1Contracts = async (
   );
   logger.info(`Deployed AvailabilityOracle at ${availabilityOracleAddress}`);
 
+  const gasTokenAddress = await deployL1Contract(
+    walletClient,
+    publicClient,
+    contractsToDeploy.gasToken.contractAbi,
+    contractsToDeploy.gasToken.contractBytecode,
+  );
+
+  logger.info(`Deployed Gas Token at ${gasTokenAddress}`);
+
   const rollupAddress = await deployL1Contract(
     walletClient,
     publicClient,
     contractsToDeploy.rollup.contractAbi,
     contractsToDeploy.rollup.contractBytecode,
-    [getAddress(registryAddress.toString()), getAddress(availabilityOracleAddress.toString())],
+    [
+      getAddress(registryAddress.toString()),
+      getAddress(availabilityOracleAddress.toString()),
+      getAddress(gasTokenAddress.toString()),
+    ],
   );
   logger.info(`Deployed Rollup at ${rollupAddress}`);
 
@@ -201,16 +214,6 @@ export const deployL1Contracts = async (
     { account },
   );
 
-  // this contract remains uninitialized because at this point we don't know the address of the gas token on L2
-  const gasTokenAddress = await deployL1Contract(
-    walletClient,
-    publicClient,
-    contractsToDeploy.gasToken.contractAbi,
-    contractsToDeploy.gasToken.contractBytecode,
-  );
-
-  logger.info(`Deployed Gas Token at ${gasTokenAddress}`);
-
   // this contract remains uninitialized because at this point we don't know the address of the gas token on L2
   const gasPortalAddress = await deployL1Contract(
     walletClient,
@@ -221,6 +224,15 @@ export const deployL1Contracts = async (
 
   logger.info(`Deployed Gas Portal at ${gasPortalAddress}`);
 
+  // fund the rollup contract with gas tokens
+  const gasToken = getContract({
+    address: gasTokenAddress.toString(),
+    abi: contractsToDeploy.gasToken.contractAbi,
+    client: walletClient,
+  });
+  await gasToken.write.mint([rollupAddress.toString(), 100000000000000000000n], {} as any);
+  logger.info(`Funded rollup contract with gas tokens`);
+
   const l1Contracts: L1ContractAddresses = {
     availabilityOracleAddress,
     rollupAddress,