chore(rollup): add function to trigger seed snapshot for next epoch

l1-contracts/src/core/RollupCore.sol

@@ -218,6 +218,10 @@ contract RollupCore is
     ExtRollupLib.setupEpoch();
   }
 
+  function setupSeedSnapshotForNextEpoch() public override(IValidatorSelectionCore) {
+    ExtRollupLib.setupSeedSnapshotForNextEpoch();
+  }
+
   /**
    * @notice  Updates the l1 gas fee oracle
    * @dev     This function is called by the `propose` function

l1-contracts/src/core/interfaces/IValidatorSelection.sol

@@ -26,6 +26,7 @@ struct ValidatorSelectionStorage {
 
 interface IValidatorSelectionCore {
   function setupEpoch() external;
+  function setupSeedSnapshotForNextEpoch() external;
 }
 
 interface IValidatorSelection is IValidatorSelectionCore {

l1-contracts/src/core/libraries/rollup/ExtRollupLib.sol

@@ -37,6 +37,11 @@ library ExtRollupLib {
     ValidatorSelectionLib.setupEpoch(StakingLib.getStorage(), currentEpoch);
   }
 
+  function setupSeedSnapshotForNextEpoch() external {
+    Epoch currentEpoch = Timestamp.wrap(block.timestamp).epochFromTimestamp();
+    ValidatorSelectionLib.setSampleSeedForNextEpoch(currentEpoch);
+  }
+
   function getEpochProofPublicInputs(
     uint256 _start,
     uint256 _end,

l1-contracts/src/core/libraries/validator-selection/ValidatorSelectionLib.sol

@@ -55,7 +55,7 @@ library ValidatorSelectionLib {
 
     // Set the sample seed for the next epoch if required
     // function handles the case where it is already set
-    setSampleSeedForEpoch(_epochNumber + Epoch.wrap(1));
+    setSampleSeedForNextEpoch(_epochNumber);
 
     //################ Committee ################
     // If the committee is not set for this epoch, we need to sample it
@@ -226,6 +226,15 @@ library ValidatorSelectionLib {
     return epoch.committee;
   }
 
+  /**
+   * @notice  Sets the sample seed for the next epoch
+   *
+   * @param _epoch - The epoch to set the sample seed for
+   */
+  function setSampleSeedForNextEpoch(Epoch _epoch) internal {
+    setSampleSeedForEpoch(_epoch + Epoch.wrap(1));
+  }
+
   /**
    * @notice  Sets the sample seed for an epoch
    *

l1-contracts/test/scream-and-shout.t.sol

@@ -20,7 +20,7 @@ contract ScreamAndShoutTest is Test {
 
     assertEq(
       codeHash,
-      0x1d16acb8153d57a5977ea83c2adfd173c4299d2501a67084e54391b49f9e17a5,
+      0xf5661dc2c5fc8908f0046f7f5a4bad9f2bdd569e730ecc36db30d3bb4e6fb57b,
       "You have changed the rollup!"
     );
   }
@@ -42,7 +42,7 @@ contract ScreamAndShoutTest is Test {
 
     assertEq(
       codeHash,
-      0xc4ca2e1a154150d0d4d8686009de461a136716e70e1fffd561442b8bc29c7af5,
+      0x6d6f5c217adc349976fc5992f0e001f83b8674c9f2206384422f8328306bb550,
       "You have changed the registry!"
     );
   }

l1-contracts/test/validator-selection/setupSampleSeed.t.sol

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2025 Aztec Labs.
+pragma solidity >=0.8.27;
+
+import {ValidatorSelectionTestBase, CheatDepositArgs} from "./ValidatorSelectionBase.sol";
+import {Epoch, Timestamp} from "@aztec/core/libraries/TimeLib.sol";
+import {Checkpoints} from "@oz/utils/structs/Checkpoints.sol";
+import {IValidatorSelection} from "@aztec/core/interfaces/IValidatorSelection.sol";
+import {TestConstants} from "../harnesses/TestConstants.sol";
+
+contract SetupSampleSeedTest is ValidatorSelectionTestBase {
+  function test_setupSampleSeed(uint16 _epochToTest) public setup(4) {
+    // Check that the epoch is not set
+    _epochToTest = uint16(bound(_epochToTest, 2, type(uint16).max));
+
+    uint256 timejump =
+      _epochToTest * TestConstants.AZTEC_EPOCH_DURATION * TestConstants.AZTEC_SLOT_DURATION;
+    uint256 originalSampleSeed =
+      rollup.getSampleSeedAt(Timestamp.wrap(block.timestamp + timejump + 1));
+
+    // Jump to just before the epoch we are testing
+    vm.warp(
+      block.timestamp
+        + (_epochToTest - 1) * TestConstants.AZTEC_EPOCH_DURATION * TestConstants.AZTEC_SLOT_DURATION
+    );
+    rollup.setupSeedSnapshotForNextEpoch();
+
+    // The sample seed should have been updated
+    uint256 newSampleSeed = rollup.getSampleSeedAt(Timestamp.wrap(block.timestamp + timejump));
+    assertTrue(newSampleSeed != originalSampleSeed);
+  }
+}

yarn-project/cli/src/cmds/l1/index.ts

@@ -352,6 +352,30 @@ export function injectCommands(program: Command, log: LogFn, debugLogger: Logger
       });
     });
 
+  program
+    .command('trigger-seed-snapshot')
+    .description('Triggers a seed snapshot for the next epoch.')
+    .option('-pk, --private-key <string>', 'The private key to use for deployment', PRIVATE_KEY)
+    .option(
+      '-m, --mnemonic <string>',
+      'The mnemonic to use in deployment',
+      'test test test test test test test test test test test junk',
+    )
+    .option('--rollup <address>', 'ethereum address of the rollup contract', parseEthereumAddress)
+    .addOption(l1RpcUrlsOption)
+    .addOption(l1ChainIdOption)
+    .action(async options => {
+      const { triggerSeedSnapshot } = await import('./trigger_seed_snapshot.js');
+      await triggerSeedSnapshot({
+        rollupAddress: options.rollup,
+        rpcUrls: options.l1RpcUrls,
+        chainId: options.l1ChainId,
+        privateKey: options.privateKey,
+        mnemonic: options.mnemonic,
+        log,
+      });
+    });
+
   program
     .command('debug-rollup')
     .description('Debugs the rollup contract.')

yarn-project/cli/src/cmds/l1/trigger_seed_snapshot.ts

@@ -0,0 +1,31 @@
+import { createEthereumChain, createExtendedL1Client } from '@aztec/ethereum';
+import type { LogFn } from '@aztec/foundation/log';
+import { RollupAbi } from '@aztec/l1-artifacts/RollupAbi';
+
+import { getContract } from 'viem';
+
+import type { RollupCommandArgs } from './update_l1_validators.js';
+
+export async function triggerSeedSnapshot({
+  rpcUrls,
+  chainId,
+  privateKey,
+  mnemonic,
+  rollupAddress,
+  log,
+}: RollupCommandArgs & { log: LogFn }) {
+  const chain = createEthereumChain(rpcUrls, chainId);
+  const client = createExtendedL1Client(rpcUrls, privateKey ?? mnemonic!, chain.chainInfo);
+
+  const rollup = getContract({
+    address: rollupAddress.toString(),
+    abi: RollupAbi,
+    client,
+  });
+
+  log('Triggering seed snapshot for next epoch');
+  const txHash = await rollup.write.setupSeedSnapshotForNextEpoch();
+  log(`Sent! | Seed snapshot setup for next epoch | tx hash: ${txHash}`);
+  const receipt = await client.waitForTransactionReceipt({ hash: txHash });
+  log(`Done! | Seed snapshot setup for next epoch | tx hash: ${txHash} | status: ${receipt.status}`);
+}