add startafter to corn

Co-authored-by: tequ <git@tequ.dev>

.github/actions/xahau-ga-build/action.yml

@@ -21,7 +21,7 @@ inputs:
     required: false
     default: ''
   compiler-id:
-    description: 'Unique identifier for compiler/version combination used for cache keys'
+    description: 'Unique identifier: compiler-version-stdlib[-gccversion] (e.g. clang-14-libstdcxx-gcc11, gcc-13-libstdcxx)'
     required: false
     default: ''
   cache_version:
@@ -36,6 +36,17 @@ inputs:
     description: 'Main branch name for restore keys'
     required: false
     default: 'dev'
+  stdlib:
+    description: 'C++ standard library to use'
+    required: true
+    type: choice
+    options:
+      - libstdcxx
+      - libcxx
+  clang_gcc_toolchain:
+    description: 'GCC version to use for Clang toolchain (e.g. 11, 13)'
+    required: false
+    default: ''
 
 runs:
   using: 'composite'
@@ -93,6 +104,38 @@ runs:
           CCACHE_ARGS="-DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache"
         fi
         
+        # Configure C++ standard library if specified
+        # libstdcxx used for clang-14/16 to work around missing lexicographical_compare_three_way in libc++
+        # libcxx can be used with clang-17+ which has full C++20 support
+        # Note: -stdlib flag is Clang-specific, GCC always uses libstdc++
+        CMAKE_CXX_FLAGS=""
+        if [[ "${{ inputs.cxx }}" == clang* ]]; then
+          # Only Clang needs the -stdlib flag
+          if [ "${{ inputs.stdlib }}" = "libstdcxx" ]; then
+            CMAKE_CXX_FLAGS="-stdlib=libstdc++"
+          elif [ "${{ inputs.stdlib }}" = "libcxx" ]; then
+            CMAKE_CXX_FLAGS="-stdlib=libc++"
+          fi
+        fi
+        # GCC always uses libstdc++ and doesn't need/support the -stdlib flag
+        
+        # Configure GCC toolchain for Clang if specified
+        if [ -n "${{ inputs.clang_gcc_toolchain }}" ] && [[ "${{ inputs.cxx }}" == clang* ]]; then
+          # Extract Clang version from compiler executable name (e.g., clang++-14 -> 14)
+          clang_version=$(echo "${{ inputs.cxx }}" | grep -oE '[0-9]+$')
+          
+          # Clang 16+ supports --gcc-install-dir (precise path specification)
+          # Clang <16 only has --gcc-toolchain (uses discovery heuristics)
+          if [ -n "$clang_version" ] && [ "$clang_version" -ge "16" ]; then
+            # Clang 16+ uses --gcc-install-dir (canonical, precise)
+            CMAKE_CXX_FLAGS="$CMAKE_CXX_FLAGS --gcc-install-dir=/usr/lib/gcc/x86_64-linux-gnu/${{ inputs.clang_gcc_toolchain }}"
+          else
+            # Clang 14-15 uses --gcc-toolchain (deprecated but necessary)
+            # Note: This still uses discovery, so we hide newer GCC versions in the workflow
+            CMAKE_CXX_FLAGS="$CMAKE_CXX_FLAGS --gcc-toolchain=/usr"
+          fi
+        fi
+        
         # Run CMake configure
         # Note: conanfile.py hardcodes 'build/generators' as the output path.
         # If we're in a 'build' folder, Conan detects this and uses just 'generators/'
@@ -101,6 +144,7 @@ runs:
         cmake .. \
           -G "${{ inputs.generator }}" \
           $CCACHE_ARGS \
+          ${CMAKE_CXX_FLAGS:+-DCMAKE_CXX_FLAGS="$CMAKE_CXX_FLAGS"} \
           -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake \
           -DCMAKE_BUILD_TYPE=${{ inputs.configuration }}
 

.github/actions/xahau-ga-dependencies/action.yml

@@ -10,7 +10,7 @@ inputs:
     required: false
     default: '.build'
   compiler-id:
-    description: 'Unique identifier for compiler/version combination used for cache keys'
+    description: 'Unique identifier: compiler-version-stdlib[-gccversion] (e.g. clang-14-libstdcxx-gcc11, gcc-13-libstdcxx)'
     required: false
     default: ''
   cache_version:
@@ -25,6 +25,13 @@ inputs:
     description: 'Main branch name for restore keys'
     required: false
     default: 'dev'
+  stdlib:
+    description: 'C++ standard library for Conan configuration (note: also in compiler-id)'
+    required: true
+    type: choice
+    options:
+      - libstdcxx
+      - libcxx
 
 outputs:
   cache-hit:
@@ -70,6 +77,7 @@ runs:
         path: |
           ~/.conan
           ~/.conan2
+        # Note: compiler-id format is compiler-version-stdlib[-gccversion]
         key: ${{ runner.os }}-conan-v${{ inputs.cache_version }}-${{ inputs.compiler-id }}-${{ hashFiles('**/conanfile.txt', '**/conanfile.py') }}-${{ inputs.configuration }}
         restore-keys: |
           ${{ runner.os }}-conan-v${{ inputs.cache_version }}-${{ inputs.compiler-id }}-${{ hashFiles('**/conanfile.txt', '**/conanfile.py') }}-

.github/workflows/xahau-ga-nix.yml

@@ -13,21 +13,146 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  build-job:
+  matrix-setup:
+    runs-on: ubuntu-latest
+    container: python:3-slim
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      - name: Generate build matrix
+        id: set-matrix
+        shell: python
+        run: |
+          import json
+          import os
+          
+          # Full matrix with all 6 compiler configurations
+          # Each configuration includes all parameters needed by the build job
+          full_matrix = [
+              {
+                  "compiler_id": "gcc-11-libstdcxx",
+                  "compiler": "gcc",
+                  "cc": "gcc-11",
+                  "cxx": "g++-11",
+                  "compiler_version": 11,
+                  "stdlib": "libstdcxx",
+                  "configuration": "Debug"
+              },
+              {
+                  "compiler_id": "gcc-13-libstdcxx",
+                  "compiler": "gcc",
+                  "cc": "gcc-13",
+                  "cxx": "g++-13",
+                  "compiler_version": 13,
+                  "stdlib": "libstdcxx",
+                  "configuration": "Debug"
+              },
+              {
+                  "compiler_id": "clang-14-libstdcxx-gcc11",
+                  "compiler": "clang",
+                  "cc": "clang-14",
+                  "cxx": "clang++-14",
+                  "compiler_version": 14,
+                  "stdlib": "libstdcxx",
+                  "clang_gcc_toolchain": 11,
+                  "configuration": "Debug"
+              },
+              {
+                  "compiler_id": "clang-16-libstdcxx-gcc13",
+                  "compiler": "clang",
+                  "cc": "clang-16",
+                  "cxx": "clang++-16",
+                  "compiler_version": 16,
+                  "stdlib": "libstdcxx",
+                  "clang_gcc_toolchain": 13,
+                  "configuration": "Debug"
+              },
+              {
+                  "compiler_id": "clang-17-libcxx",
+                  "compiler": "clang",
+                  "cc": "clang-17",
+                  "cxx": "clang++-17",
+                  "compiler_version": 17,
+                  "stdlib": "libcxx",
+                  "configuration": "Debug"
+              },
+              {
+                  # Clang 18 - testing if it's faster than Clang 17 with libc++
+                  # Requires patching Conan v1 settings.yml to add version 18
+                  "compiler_id": "clang-18-libcxx",
+                  "compiler": "clang",
+                  "cc": "clang-18",
+                  "cxx": "clang++-18",
+                  "compiler_version": 18,
+                  "stdlib": "libcxx",
+                  "configuration": "Debug"
+              }
+          ]
+          
+          # Minimal matrix for PRs and feature branches
+          minimal_matrix = [
+              full_matrix[1],  # gcc-13 (middle-ground gcc)
+              full_matrix[2]   # clang-14 (mature, stable clang)
+          ]
+          
+          # Determine which matrix to use based on the target branch
+          ref = "${{ github.ref }}"
+          base_ref = "${{ github.base_ref }}"  # For PRs, this is the target branch
+          event_name = "${{ github.event_name }}"
+          commit_message = """${{ github.event.head_commit.message }}"""
+          pr_title = """${{ github.event.pull_request.title }}"""
+          
+          # Debug logging
+          print(f"Event: {event_name}")
+          print(f"Ref: {ref}")
+          print(f"Base ref: {base_ref}")
+          print(f"PR title: {pr_title}")
+          print(f"Commit message: {commit_message}")
+          
+          # Check for override tags in commit message or PR title
+          force_full = "[ci-nix-full-matrix]" in commit_message or "[ci-nix-full-matrix]" in pr_title
+          print(f"Force full matrix: {force_full}")
+          
+          # Check if this is targeting a main branch
+          # For PRs: check base_ref (target branch)
+          # For pushes: check ref (current branch)
+          main_branches = ["refs/heads/dev", "refs/heads/release", "refs/heads/candidate"]
+          
+          if force_full:
+              # Override: always use full matrix if tag is present
+              use_full = True
+          elif event_name == "pull_request":
+              # For PRs, base_ref is just the branch name (e.g., "dev", not "refs/heads/dev")
+              # Check if the PR targets release or candidate (more critical branches)
+              use_full = base_ref in ["release", "candidate"]
+          else:
+              # For pushes, ref is the full reference (e.g., "refs/heads/dev")
+              use_full = ref in main_branches
+          
+          # Select the appropriate matrix
+          if use_full:
+              if force_full:
+                  print(f"Using FULL matrix (6 configs) - forced by [ci-nix-full-matrix] tag")
+              else:
+                  print(f"Using FULL matrix (6 configs) - targeting main branch")
+              matrix = full_matrix
+          else:
+              print(f"Using MINIMAL matrix (2 configs) - feature branch/PR")
+              matrix = minimal_matrix
+          
+          # Output the matrix as JSON
+          output = json.dumps({"include": matrix})
+          with open(os.environ['GITHUB_OUTPUT'], 'a') as f:
+              f.write(f"matrix={output}\n")
+
+  build:
+    needs: matrix-setup
     runs-on: ubuntu-latest
     outputs:
       artifact_name: ${{ steps.set-artifact-name.outputs.artifact_name }}
     strategy:
       fail-fast: false
-      matrix:
-        compiler: [gcc]
-        configuration: [Debug]
-        include:
-          - compiler: gcc
-            cc: gcc-13
-            cxx: g++-13
-            compiler_id: gcc-13
-            compiler_version: 13
+      matrix: ${{ fromJSON(needs.matrix-setup.outputs.matrix) }}
     env:
       build_dir: .build
       # Bump this number to invalidate all caches globally.
@@ -41,8 +166,70 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y ninja-build ${{ matrix.cc }} ${{ matrix.cxx }} ccache
+
+          # Install the specific GCC version needed for Clang
+          if [ -n "${{ matrix.clang_gcc_toolchain }}" ]; then
+            echo "=== Installing GCC ${{ matrix.clang_gcc_toolchain }} for Clang ==="
+            sudo apt-get install -y gcc-${{ matrix.clang_gcc_toolchain }} g++-${{ matrix.clang_gcc_toolchain }} libstdc++-${{ matrix.clang_gcc_toolchain }}-dev
+
+            echo "=== GCC versions available after installation ==="
+            ls -la /usr/lib/gcc/x86_64-linux-gnu/ | grep -E "^d"
+          fi
+
+          # For Clang < 16 with --gcc-toolchain, hide newer GCC versions
+          # This is needed because --gcc-toolchain still picks the highest version
+          #
+          # THE GREAT GCC HIDING TRICK (for Clang < 16):
+          # Clang versions before 16 don't have --gcc-install-dir, only --gcc-toolchain
+          # which is deprecated and still uses discovery heuristics that ALWAYS pick
+          # the highest version number. So we play a sneaky game...
+          #
+          # We rename newer GCC versions to very low integers (1, 2, 3...) which makes
+          # Clang think they're ancient GCC versions. Since 11 > 3 > 2 > 1, Clang will
+          # pick GCC 11 over our renamed versions. It's dumb but it works!
+          #
+          # Example: GCC 12→1, GCC 13→2, GCC 14→3, so Clang picks 11 (highest number)
+          if [ -n "${{ matrix.clang_gcc_toolchain }}" ] && [ "${{ matrix.compiler_version }}" -lt "16" ]; then
+            echo "=== Hiding GCC versions newer than ${{ matrix.clang_gcc_toolchain }} for Clang < 16 ==="
+            target_version=${{ matrix.clang_gcc_toolchain }}
+            counter=1  # Start with 1 - these will be seen as "GCC version 1, 2, 3" etc
+            for dir in /usr/lib/gcc/x86_64-linux-gnu/*/; do
+              if [ -d "$dir" ]; then
+                version=$(basename "$dir")
+                # Check if version is numeric and greater than target
+                if [[ "$version" =~ ^[0-9]+$ ]] && [ "$version" -gt "$target_version" ]; then
+                  echo "Hiding GCC $version -> renaming to $counter (will be seen as GCC version $counter)"
+                  # Safety check: ensure target doesn't already exist
+                  if [ ! -e "/usr/lib/gcc/x86_64-linux-gnu/$counter" ]; then
+                    sudo mv "$dir" "/usr/lib/gcc/x86_64-linux-gnu/$counter"
+                  else
+                    echo "ERROR: Cannot rename GCC $version - /usr/lib/gcc/x86_64-linux-gnu/$counter already exists"
+                    exit 1
+                  fi
+                  counter=$((counter + 1))
+                fi
+              fi
+            done
+          fi
+
+          # Verify what Clang will use
+          if [ -n "${{ matrix.clang_gcc_toolchain }}" ]; then
+            echo "=== Verifying GCC toolchain selection ==="
+            echo "Available GCC versions:"
+            ls -la /usr/lib/gcc/x86_64-linux-gnu/ | grep -E "^d.*[0-9]+$" || true
+
+            echo ""
+            echo "Clang's detected GCC installation:"
+            ${{ matrix.cxx }} -v -E -x c++ /dev/null -o /dev/null 2>&1 | grep "Found candidate GCC installation" || true
+          fi
+
+          # Install libc++ dev packages if using libc++ (not needed for libstdc++)
+          if [ "${{ matrix.stdlib }}" = "libcxx" ]; then
+            sudo apt-get install -y libc++-${{ matrix.compiler_version }}-dev libc++abi-${{ matrix.compiler_version }}-dev
+          fi
+
           # Install Conan 2
-          pip install --upgrade "conan>=2.0"
+          pip install --upgrade "conan>=2.0,<3"
 
       - name: Configure ccache
         uses: ./.github/actions/xahau-configure-ccache
@@ -57,14 +244,21 @@ jobs:
           # Create the default profile directory if it doesn't exist
           mkdir -p ~/.conan2/profiles
 
+          # Determine the correct libcxx based on stdlib parameter
+          if [ "${{ matrix.stdlib }}" = "libcxx" ]; then
+            LIBCXX="libc++"
+          else
+            LIBCXX="libstdc++11"
+          fi
+
           # Create profile with our specific settings
           cat > ~/.conan2/profiles/default <<EOF
           [settings]
           arch=x86_64
-          build_type=Release
+          build_type=${{ matrix.configuration }}
           compiler=${{ matrix.compiler }}
           compiler.cppstd=20
-          compiler.libcxx=libstdc++11
+          compiler.libcxx=${LIBCXX}
           compiler.version=${{ matrix.compiler_version }}
           os=Linux
 
@@ -99,6 +293,7 @@ jobs:
           compiler-id: ${{ matrix.compiler_id }}
           cache_version: ${{ env.CACHE_VERSION }}
           main_branch: ${{ env.MAIN_BRANCH_NAME }}
+          stdlib: ${{ matrix.stdlib }}
 
       - name: Build
         uses: ./.github/actions/xahau-ga-build
@@ -111,6 +306,8 @@ jobs:
           compiler-id: ${{ matrix.compiler_id }}
           cache_version: ${{ env.CACHE_VERSION }}
           main_branch: ${{ env.MAIN_BRANCH_NAME }}
+          stdlib: ${{ matrix.stdlib }}
+          clang_gcc_toolchain: ${{ matrix.clang_gcc_toolchain || '' }}
 
       - name: Set artifact name
         id: set-artifact-name

Builds/CMake/RippledCore.cmake

@@ -457,6 +457,7 @@ target_sources (rippled PRIVATE
   src/ripple/app/tx/impl/CreateCheck.cpp
   src/ripple/app/tx/impl/CreateOffer.cpp
   src/ripple/app/tx/impl/CreateTicket.cpp
+  src/ripple/app/tx/impl/Cron.cpp
   src/ripple/app/tx/impl/DeleteAccount.cpp
   src/ripple/app/tx/impl/DepositPreauth.cpp
   src/ripple/app/tx/impl/Escrow.cpp
@@ -474,6 +475,7 @@ target_sources (rippled PRIVATE
   src/ripple/app/tx/impl/Payment.cpp
   src/ripple/app/tx/impl/Remit.cpp
   src/ripple/app/tx/impl/SetAccount.cpp
+  src/ripple/app/tx/impl/SetCron.cpp
   src/ripple/app/tx/impl/SetHook.cpp
   src/ripple/app/tx/impl/SetRemarks.cpp
   src/ripple/app/tx/impl/SetRegularKey.cpp
@@ -734,6 +736,7 @@ if (tests)
     src/test/app/BaseFee_test.cpp
     src/test/app/Check_test.cpp
     src/test/app/ClaimReward_test.cpp
+    src/test/app/Cron_test.cpp
     src/test/app/Clawback_test.cpp
     src/test/app/CrossingLimits_test.cpp
     src/test/app/DeliverMin_test.cpp
@@ -898,6 +901,7 @@ if (tests)
     src/test/jtx/impl/amount.cpp
     src/test/jtx/impl/balance.cpp
     src/test/jtx/impl/check.cpp
+    src/test/jtx/impl/cron.cpp
     src/test/jtx/impl/delivermin.cpp
     src/test/jtx/impl/deposit.cpp
     src/test/jtx/impl/envconfig.cpp

src/ripple/app/hook/impl/applyHook.cpp

@@ -75,6 +75,11 @@ getTransactionalStakeHolders(STTx const& tx, ReadView const& rv)
 
     switch (tt)
     {
+        case ttCRON: {
+            ADD_TSH(tx.getAccountID(sfOwner), tshWEAK);
+            break;
+        }
+
         case ttREMIT: {
             if (destAcc)
                 ADD_TSH(*destAcc, tshSTRONG);
@@ -3577,7 +3582,7 @@ DEFINE_HOOK_FUNCTION(
     {
         JLOG(j.trace()) << "HookEmit[" << HC_ACC()
                         << "]: Transaction preflight failure: "
-                        << preflightResult.ter;
+                        << transHuman(preflightResult.ter);
         return EMISSION_FAILURE;
     }
 

src/ripple/app/misc/impl/TxQ.cpp

@@ -1477,6 +1477,64 @@ TxQ::accept(Application& app, OpenView& view)
         }
     }
 
+    // Inject cron transactions, if any
+    if (view.rules().enabled(featureCron))
+    {
+        uint32_t currentTime =
+            view.parentCloseTime().time_since_epoch().count();
+        uint256 klStart = keylet::cron(0, AccountID(beast::zero)).key;
+        uint256 const klEnd =
+            keylet::cron(currentTime + 1, AccountID(beast::zero)).key;
+
+        std::set<AccountID> cronAccs;
+
+        auto counter = 0;
+        // include max 128 cron txns in the ledger
+        while (++counter < 129 && klStart < klEnd)
+        {
+            std::optional<uint256 const> next = view.succ(klStart, klEnd);
+            if (!next.has_value())
+                break;
+
+            Keylet kl{ltANY, *next};
+
+            if (view.exists(kl))
+            {
+                auto sle = view.read(kl);
+                if (safe_cast<LedgerEntryType>(
+                        sle->getFieldU16(sfLedgerEntryType)) == ltCRON)
+                {
+                    // valid cron object, add it to the list
+                    cronAccs.emplace(sle->getAccountID(sfOwner));
+                }
+            }
+
+            klStart = *next;
+        }
+
+        auto const seq = view.info().seq;
+
+        // insert Cron pseudos for each of the accs we need to ping
+        for (AccountID const& id : cronAccs)
+        {
+            STTx cronTx(ttCRON, [=](auto& obj) {
+                obj[sfAccount] = AccountID();
+                obj[sfLedgerSequence] = seq;
+                obj[sfOwner] = id;
+            });
+
+            uint256 txID = cronTx.getTransactionID();
+
+            auto s = std::make_shared<ripple::Serializer>();
+            cronTx.add(*s);
+
+            app.getHashRouter().setFlags(txID, SF_PRIVATE2);
+            app.getHashRouter().setFlags(txID, SF_EMITTED);
+            view.rawTxInsert(txID, std::move(s), nullptr);
+            ledgerChanged = true;
+        }
+    }
+
     // Inject emitted transactions if any
     if (view.rules().enabled(featureHooks))
         do

src/ripple/app/tx/impl/Cron.cpp

@@ -0,0 +1,188 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2024 XRPL-Labs
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <ripple/app/tx/impl/Cron.h>
+#include <ripple/basics/Log.h>
+#include <ripple/core/Config.h>
+#include <ripple/ledger/View.h>
+#include <ripple/protocol/Feature.h>
+#include <ripple/protocol/Indexes.h>
+#include <ripple/protocol/PublicKey.h>
+#include <ripple/protocol/Quality.h>
+#include <ripple/protocol/TxFlags.h>
+#include <ripple/protocol/st.h>
+
+namespace ripple {
+
+TxConsequences
+Cron::makeTxConsequences(PreflightContext const& ctx)
+{
+    return TxConsequences{ctx.tx, TxConsequences::normal};
+}
+
+NotTEC
+Cron::preflight(PreflightContext const& ctx)
+{
+    if (!ctx.rules.enabled(featureCron))
+        return temDISABLED;
+
+    auto const ret = preflight0(ctx);
+    if (!isTesSuccess(ret))
+        return ret;
+
+    auto account = ctx.tx.getAccountID(sfAccount);
+    if (account != beast::zero)
+    {
+        JLOG(ctx.j.warn()) << "Cron: Bad source id";
+        return temBAD_SRC_ACCOUNT;
+    }
+
+    // No point in going any further if the transaction fee is malformed.
+    auto const fee = ctx.tx.getFieldAmount(sfFee);
+    if (!fee.native() || fee != beast::zero)
+    {
+        JLOG(ctx.j.warn()) << "Cron: invalid fee";
+        return temBAD_FEE;
+    }
+
+    if (!ctx.tx.getSigningPubKey().empty() || !ctx.tx.getSignature().empty() ||
+        ctx.tx.isFieldPresent(sfSigners))
+    {
+        JLOG(ctx.j.warn()) << "Cron: Bad signature";
+        return temBAD_SIGNATURE;
+    }
+
+    if (ctx.tx.getFieldU32(sfSequence) != 0 ||
+        ctx.tx.isFieldPresent(sfPreviousTxnID))
+    {
+        JLOG(ctx.j.warn()) << "Cron: Bad sequence";
+        return temBAD_SEQUENCE;
+    }
+
+    return tesSUCCESS;
+}
+
+TER
+Cron::preclaim(PreclaimContext const& ctx)
+{
+    if (!ctx.view.rules().enabled(featureCron))
+        return temDISABLED;
+
+    return tesSUCCESS;
+}
+
+TER
+Cron::doApply()
+{
+    auto& view = ctx_.view();
+    auto const& tx = ctx_.tx;
+
+    AccountID const& id = tx.getAccountID(sfOwner);
+
+    auto sle = view.peek(keylet::account(id));
+    if (!sle)
+    {
+        // should never happen... but might in a race condition with acc delete
+        JLOG(j_.warn()) << "Cron: sfOwner account missing. " << id;
+        return tesSUCCESS;
+    }
+
+    if (!sle->isFieldPresent(sfCron))
+    {
+        JLOG(j_.warn()) << "Cron: sfCron missing from account " << id;
+        return tefINTERNAL;
+    }
+
+    uint256 ptr = sle->getFieldH256(sfCron);
+    Keylet klOld{ltCRON, ptr};
+    auto sleCron = view.peek(klOld);
+    if (!sleCron)
+    {
+        JLOG(j_.warn()) << "Cron: Cron object missing for account " << id;
+        return tesSUCCESS;
+    }
+
+    uint32_t delay = sleCron->getFieldU32(sfDelaySeconds);
+    uint32_t recur = sleCron->getFieldU32(sfRepeatCount);
+
+    uint32_t currentTime = view.parentCloseTime().time_since_epoch().count();
+
+    // do all this sanity checking before we modify the ledger...
+    uint32_t afterTime = currentTime + delay;
+    if (afterTime < currentTime)
+        return tefINTERNAL;
+
+    // in all circumstances the Cron object is deleted...
+    // if there are further crons to do then a new one is created at the next
+    // time point
+
+    if (!view.dirRemove(
+            keylet::ownerDir(id), (*sleCron)[sfOwnerNode], klOld, false))
+        return tefBAD_LEDGER;
+
+    view.erase(sleCron);
+
+    if (recur == 0)
+    {
+        // already at last execution, stop here
+        adjustOwnerCount(view, sle, -1, j_);
+        sle->makeFieldAbsent(sfCron);
+        view.update(sle);
+        return tesSUCCESS;
+    }
+
+    // more executions remain, so create a new object
+
+    Keylet klCron = keylet::cron(afterTime, id);
+
+    // insert into owner dir, we don't need to check reserve because we've just
+    // deleted an object
+    auto const page =
+        view.dirInsert(keylet::ownerDir(id), klCron, describeOwnerDir(id));
+    if (!page)
+        return tecDIR_FULL;
+
+    sleCron = std::make_shared<SLE>(klCron);
+
+    sleCron->setFieldU64(sfOwnerNode, *page);
+    sleCron->setFieldU32(sfDelaySeconds, delay);
+    sleCron->setFieldU32(sfRepeatCount, recur - 1);
+    sleCron->setAccountID(sfOwner, id);
+
+    sle->setFieldH256(sfCron, klCron.key);
+
+    view.insert(sleCron);
+    view.update(sle);
+
+    return tesSUCCESS;
+}
+
+void
+Cron::preCompute()
+{
+    assert(account_ == beast::zero);
+}
+
+XRPAmount
+Cron::calculateBaseFee(ReadView const& view, STTx const& tx)
+{
+    return XRPAmount{0};
+}
+
+}  // namespace ripple

src/ripple/app/tx/impl/Cron.h

@@ -0,0 +1,60 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2024 XRPL-Labs
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_TX_CRON_H_INCLUDED
+#define RIPPLE_TX_CRON_H_INCLUDED
+
+#include <ripple/app/tx/impl/Transactor.h>
+#include <ripple/basics/Log.h>
+#include <ripple/core/Config.h>
+#include <ripple/protocol/Indexes.h>
+
+namespace ripple {
+
+class Cron : public Transactor
+{
+public:
+    static constexpr ConsequencesFactoryType ConsequencesFactory{Custom};
+
+    explicit Cron(ApplyContext& ctx) : Transactor(ctx)
+    {
+    }
+
+    static XRPAmount
+    calculateBaseFee(ReadView const& view, STTx const& tx);
+
+    static TxConsequences
+    makeTxConsequences(PreflightContext const& ctx);
+
+    static NotTEC
+    preflight(PreflightContext const& ctx);
+
+    static TER
+    preclaim(PreclaimContext const&);
+
+    TER
+    doApply() override;
+
+    void
+    preCompute() override;
+};
+
+}  // namespace ripple
+
+#endif

src/ripple/app/tx/impl/InvariantCheck.cpp

@@ -491,6 +491,7 @@ LedgerEntryTypesMatch::visitEntry(
             case ltNFTOKEN_PAGE:
             case ltNFTOKEN_OFFER:
             case ltURI_TOKEN:
+            case ltCRON:
             case ltIMPORT_VLSEQ:
             case ltUNL_REPORT:
                 break;

src/ripple/app/tx/impl/SetCron.cpp

@@ -0,0 +1,317 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2024 XRPL-Labs
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <ripple/app/tx/impl/SetCron.h>
+#include <ripple/basics/Log.h>
+#include <ripple/ledger/View.h>
+#include <ripple/protocol/Feature.h>
+#include <ripple/protocol/Indexes.h>
+#include <ripple/protocol/TxFlags.h>
+#include <ripple/protocol/st.h>
+
+namespace ripple {
+
+TxConsequences
+SetCron::makeTxConsequences(PreflightContext const& ctx)
+{
+    return TxConsequences{ctx.tx, TxConsequences::normal};
+}
+
+NotTEC
+SetCron::preflight(PreflightContext const& ctx)
+{
+    if (!ctx.rules.enabled(featureCron))
+        return temDISABLED;
+
+    if (auto const ret = preflight1(ctx); !isTesSuccess(ret))
+        return ret;
+
+    auto& tx = ctx.tx;
+    auto& j = ctx.j;
+
+    if (tx.getFlags() & tfCronSetMask)
+    {
+        JLOG(j.warn()) << "SetCron: Invalid flags set.";
+        return temINVALID_FLAG;
+    }
+
+    // StartAfter(s) DelaySeconds (D), RepeatCount (R)
+
+    // SDR - Set Cron with After, Delay and Repeat
+    // SD- - Invalid, if repeat count isn't included then only start or delay
+    // S-R - Invalid
+    // S-- - Set Cron with After for a once off execution
+
+    // -DR - Set Cron with Delay and Repeat
+    // -D- - Set Cron (once off) with Delay only (repat implicitly 0)
+    // --R - Invalid
+    // --- - Clear any existing cron (succeeds even if there isn't one) / with
+    // tfCronUnset flag set
+
+    bool const hasStart = tx.isFieldPresent(sfStartAfter);
+    bool const hasDelay = tx.isFieldPresent(sfDelaySeconds);
+    bool const hasRepeat = tx.isFieldPresent(sfRepeatCount);
+
+    // unset is a special case, handle first
+    if (tx.isFlag(tfCronUnset))
+    {
+        if (hasDelay || hasRepeat || hasStart)
+        {
+            JLOG(j.debug()) << "SetCron: tfCronUnset flag cannot be used with "
+                               "DelaySeconds or RepeatCount.";
+            return temMALFORMED;
+        }
+
+        return preflight2(ctx);
+    }
+
+    if (hasStart)
+    {
+        if (hasRepeat && hasDelay)
+        {
+            // valid, this is a fully specified cron
+            // fall through to validate other fields
+        }
+        else if (!hasRepeat && !hasDelay)
+        {
+            // valid this is a once off cron
+            // no other fields to validate, done
+            return preflight2(ctx);
+        }
+        else
+        {
+            // invalid, must specify both or neither repeat and delay count with
+            // startafter
+            JLOG(j.debug()) << "SetCron: StartAfter can only be used with "
+                               "either both or neither of "
+                               "DelaySeconds and RepeatCount.";
+            return temMALFORMED;
+        }
+    }
+
+    if (!hasDelay)
+    {
+        JLOG(j.debug()) << "SetCron: DelaySeconds or StartAfter must be "
+                           "specified to create a cron.";
+        return temMALFORMED;
+    }
+
+    // check delay is not too high
+    auto delay = tx.getFieldU32(sfDelaySeconds);
+    if (delay > 31536000UL /* 365 days in seconds */)
+    {
+        JLOG(j.debug()) << "SetCron: DelaySeconds was too high. (max 365 "
+                           "days in seconds).";
+        return temMALFORMED;
+    }
+
+    // check repeat is not too high
+    if (hasRepeat)
+    {
+        auto recur = tx.getFieldU32(sfRepeatCount);
+        if (recur > 256)
+        {
+            JLOG(j.debug())
+                << "SetCron: RepeatCount too high. Limit is 256. Issue "
+                   "new SetCron to increase.";
+            return temMALFORMED;
+        }
+    }
+
+    return preflight2(ctx);
+}
+
+TER
+SetCron::preclaim(PreclaimContext const& ctx)
+{
+    if (ctx.tx.isFieldPresent(sfStartAfter))
+    {
+        uint32_t currentTime =
+            ctx.view.parentCloseTime().time_since_epoch().count();
+        uint32_t afterTime = ctx.tx.getFieldU32(sfStartAfter);
+
+        if (afterTime <= currentTime)
+        {
+            // we'll pass this as though they meant execute asap, similar to a
+            // delay of 0
+            return tesSUCCESS;
+        }
+
+        uint32_t waitSeconds = afterTime - currentTime;
+
+        if (waitSeconds > afterTime)
+            return tefINTERNAL;
+
+        if (waitSeconds >> 31536000UL /* 365 days in seconds */)
+        {
+            JLOG(ctx.j.debug())
+                << "SetCron: DelaySeconds was too high. (max 365 "
+                   "days in seconds).";
+            return tecSTART_AFTER_TOO_HIGH;
+        }
+    }
+    return tesSUCCESS;
+}
+
+TER
+SetCron::doApply()
+{
+    auto& view = ctx_.view();
+    auto const& tx = ctx_.tx;
+
+    bool const isDelete = tx.isFlag(tfCronUnset);
+
+    // delay can be zero, in which case the cron will usually execute next
+    // ledger.
+    uint32_t delay{0};
+    uint32_t recur{0};
+    uint32_t after{0};
+
+    if (!isDelete)
+    {
+        if (tx.isFieldPresent(sfDelaySeconds))
+            delay = tx.getFieldU32(sfDelaySeconds);
+        if (tx.isFieldPresent(sfRepeatCount))
+            recur = tx.getFieldU32(sfRepeatCount);
+    }
+
+    uint32_t currentTime = view.parentCloseTime().time_since_epoch().count();
+
+    // do all this sanity checking before we modify the ledger...
+    // even for a delete operation this will fall through without incident
+
+    uint32_t afterTime = tx.isFieldPresent(sfStartAfter)
+        ? tx.getFieldU32(sfStartAfter)
+        : currentTime + delay;
+
+    if (afterTime < currentTime)
+        return tefINTERNAL;
+
+    AccountID const& id = tx.getAccountID(sfAccount);
+    auto sle = view.peek(keylet::account(id));
+    if (!sle)
+        return tefINTERNAL;
+
+    // in all cases whatsoever, this transaction will delete an existing
+    // old cron object and return the owner reserve to the owner.
+
+    if (sle->isFieldPresent(sfCron))
+    {
+        Keylet klOld{ltCRON, sle->getFieldH256(sfCron)};
+
+        auto sleCron = view.peek(klOld);
+        if (!sleCron)
+        {
+            JLOG(j_.warn()) << "SetCron: Cron object didn't exist.";
+            return tefBAD_LEDGER;
+        }
+
+        if (safe_cast<LedgerEntryType>(
+                sleCron->getFieldU16(sfLedgerEntryType)) != ltCRON)
+        {
+            JLOG(j_.warn()) << "SetCron: sfCron pointed to non-cron object!!";
+            return tefBAD_LEDGER;
+        }
+
+        if (!view.dirRemove(
+                keylet::ownerDir(id), (*sleCron)[sfOwnerNode], klOld, false))
+        {
+            JLOG(j_.warn()) << "SetCron: Ownerdir bad. " << id;
+            return tefBAD_LEDGER;
+        }
+
+        view.erase(sleCron);
+        adjustOwnerCount(view, sle, -1, j_);
+        sle->makeFieldAbsent(sfCron);
+    }
+
+    // if the operation is a delete (no delay or recur specified then stop
+    // here.)
+    if (isDelete)
+    {
+        view.update(sle);
+        return tesSUCCESS;
+    }
+
+    // execution to here means we're creating a new Cron object and adding it to
+    // the user's owner dir
+
+    Keylet klCron = keylet::cron(afterTime, id);
+
+    std::shared_ptr<SLE> sleCron = std::make_shared<SLE>(klCron);
+
+    STAmount const reserve{
+        view.fees().accountReserve(sle->getFieldU32(sfOwnerCount) + 1)};
+
+    STAmount const afterFee =
+        mPriorBalance - ctx_.tx.getFieldAmount(sfFee).xrp();
+
+    if (afterFee > mPriorBalance || afterFee < reserve)
+        return tecINSUFFICIENT_RESERVE;
+
+    // add to owner dir
+    auto const page =
+        view.dirInsert(keylet::ownerDir(id), klCron, describeOwnerDir(id));
+    if (!page)
+        return tecDIR_FULL;
+
+    sleCron->setFieldU64(sfOwnerNode, *page);
+
+    adjustOwnerCount(view, sle, 1, j_);
+
+    // set the fields
+    sleCron->setFieldU32(sfDelaySeconds, delay);
+    sleCron->setFieldU32(sfRepeatCount, recur);
+    sleCron->setAccountID(sfOwner, id);
+
+    sle->setFieldH256(sfCron, klCron.key);
+
+    view.update(sle);
+
+    view.insert(sleCron);
+
+    return tesSUCCESS;
+}
+
+XRPAmount
+SetCron::calculateBaseFee(ReadView const& view, STTx const& tx)
+{
+    auto const baseFee = Transactor::calculateBaseFee(view, tx);
+
+    auto const hasRepeat = tx.isFieldPresent(sfRepeatCount);
+
+    if (tx.isFlag(tfCronUnset))
+        // delete cron
+        return baseFee;
+
+    // factor a cost based on the total number of txns expected
+    // for RepeatCount of 0 we have this txn (SetCron) and the
+    // single Cron txn (2). For a RepeatCount of 1 we have this txn,
+    // the first time the cron executes, and the second time (3).
+    uint32_t const additionalExpectedExecutions =
+        hasRepeat ? tx.getFieldU32(sfRepeatCount) + 1 : 1;
+    auto const additionalFee = baseFee * additionalExpectedExecutions;
+
+    if (baseFee + additionalFee < baseFee)
+        return baseFee;
+
+    return baseFee + additionalFee;
+}
+
+}  // namespace ripple

src/ripple/app/tx/impl/SetCron.h

@@ -0,0 +1,56 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2024 XRPL-Labs
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_TX_SETCRON_H_INCLUDED
+#define RIPPLE_TX_SETCRON_H_INCLUDED
+
+#include <ripple/app/tx/impl/Transactor.h>
+#include <ripple/basics/Log.h>
+#include <ripple/protocol/Indexes.h>
+
+namespace ripple {
+
+class SetCron : public Transactor
+{
+public:
+    static constexpr ConsequencesFactoryType ConsequencesFactory{Custom};
+
+    explicit SetCron(ApplyContext& ctx) : Transactor(ctx)
+    {
+    }
+
+    static XRPAmount
+    calculateBaseFee(ReadView const& view, STTx const& tx);
+
+    static TxConsequences
+    makeTxConsequences(PreflightContext const& ctx);
+
+    static NotTEC
+    preflight(PreflightContext const& ctx);
+
+    static TER
+    preclaim(PreclaimContext const&);
+
+    TER
+    doApply() override;
+};
+
+}  // namespace ripple
+
+#endif

src/ripple/app/tx/impl/applySteps.cpp

@@ -28,6 +28,7 @@
 #include <ripple/app/tx/impl/CreateCheck.h>
 #include <ripple/app/tx/impl/CreateOffer.h>
 #include <ripple/app/tx/impl/CreateTicket.h>
+#include <ripple/app/tx/impl/Cron.h>
 #include <ripple/app/tx/impl/DeleteAccount.h>
 #include <ripple/app/tx/impl/DepositPreauth.h>
 #include <ripple/app/tx/impl/Escrow.h>
@@ -43,6 +44,7 @@
 #include <ripple/app/tx/impl/Payment.h>
 #include <ripple/app/tx/impl/Remit.h>
 #include <ripple/app/tx/impl/SetAccount.h>
+#include <ripple/app/tx/impl/SetCron.h>
 #include <ripple/app/tx/impl/SetHook.h>
 #include <ripple/app/tx/impl/SetRegularKey.h>
 #include <ripple/app/tx/impl/SetRemarks.h>
@@ -181,6 +183,10 @@ invoke_preflight(PreflightContext const& ctx)
         case ttURITOKEN_CREATE_SELL_OFFER:
         case ttURITOKEN_CANCEL_SELL_OFFER:
             return invoke_preflight_helper<URIToken>(ctx);
+        case ttCRON_SET:
+            return invoke_preflight_helper<SetCron>(ctx);
+        case ttCRON:
+            return invoke_preflight_helper<Cron>(ctx);
         default:
             assert(false);
             return {temUNKNOWN, TxConsequences{temUNKNOWN}};
@@ -306,6 +312,10 @@ invoke_preclaim(PreclaimContext const& ctx)
         case ttURITOKEN_CREATE_SELL_OFFER:
         case ttURITOKEN_CANCEL_SELL_OFFER:
             return invoke_preclaim<URIToken>(ctx);
+        case ttCRON_SET:
+            return invoke_preclaim<SetCron>(ctx);
+        case ttCRON:
+            return invoke_preclaim<Cron>(ctx);
         default:
             assert(false);
             return temUNKNOWN;
@@ -393,6 +403,10 @@ invoke_calculateBaseFee(ReadView const& view, STTx const& tx)
         case ttURITOKEN_CREATE_SELL_OFFER:
         case ttURITOKEN_CANCEL_SELL_OFFER:
             return URIToken::calculateBaseFee(view, tx);
+        case ttCRON_SET:
+            return SetCron::calculateBaseFee(view, tx);
+        case ttCRON:
+            return Cron::calculateBaseFee(view, tx);
         default:
             return XRPAmount{0};
     }
@@ -586,6 +600,14 @@ invoke_apply(ApplyContext& ctx)
             URIToken p(ctx);
             return p();
         }
+        case ttCRON_SET: {
+            SetCron p(ctx);
+            return p();
+        }
+        case ttCRON: {
+            Cron p(ctx);
+            return p();
+        }
         default:
             assert(false);
             return {temUNKNOWN, false};

src/ripple/protocol/Feature.h

@@ -74,7 +74,7 @@ namespace detail {
 // Feature.cpp. Because it's only used to reserve storage, and determine how
 // large to make the FeatureBitset, it MAY be larger. It MUST NOT be less than
 // the actual number of amendments. A LogicError on startup will verify this.
-static constexpr std::size_t numFeatures = 86;
+static constexpr std::size_t numFeatures = 87;
 
 /** Amendments that this server supports and the default voting behavior.
    Whether they are enabled depends on the Rules defined in the validated
@@ -373,6 +373,7 @@ extern uint256 const fixProvisionalDoubleThreading;
 extern uint256 const featureClawback;
 extern uint256 const featureDeepFreeze;
 extern uint256 const featureIOUIssuerWeakTSH;
+extern uint256 const featureCron;
 extern uint256 const fixInvalidTxFlags;
 
 }  // namespace ripple

src/ripple/protocol/Indexes.h

@@ -297,6 +297,9 @@ import_vlseq(PublicKey const& key) noexcept;
 Keylet
 uritoken(AccountID const& issuer, Blob const& uri);
 
+Keylet
+cron(uint32_t timestamp, AccountID const& id);
+
 }  // namespace keylet
 
 // Everything below is deprecated and should be removed in favor of keylets:

src/ripple/protocol/LedgerFormats.h

@@ -58,6 +58,12 @@ enum LedgerEntryType : std::uint16_t
      */
     ltACCOUNT_ROOT = 0x0061,
 
+    /** A ledger object representing a scheduled cron execution on an account.
+     
+        \sa keylet::cron
+    */
+    ltCRON = 0x0041,
+
     /** A ledger object which contains a list of object identifiers.
 
         \sa keylet::page, keylet::quality, keylet::book, keylet::next and

src/ripple/protocol/SField.h

@@ -410,6 +410,9 @@ extern SF_UINT32 const sfRewardLgrLast;
 extern SF_UINT32 const sfFirstNFTokenSequence;
 extern SF_UINT32 const sfImportSequence;
 extern SF_UINT32 const sfXahauActivationLgrSeq;
+extern SF_UINT32 const sfDelaySeconds;
+extern SF_UINT32 const sfRepeatCount;
+extern SF_UINT32 const sfStartAfter;
 
 // 64-bit integers (common)
 extern SF_UINT64 const sfIndexNext;
@@ -486,6 +489,7 @@ extern SF_UINT256 const sfURITokenID;
 extern SF_UINT256 const sfGovernanceFlags;
 extern SF_UINT256 const sfGovernanceMarks;
 extern SF_UINT256 const sfEmittedTxnID;
+extern SF_UINT256 const sfCron;
 
 // currency amount (common)
 extern SF_AMOUNT const sfAmount;

src/ripple/protocol/TER.h

@@ -343,6 +343,7 @@ enum TECcodes : TERUnderlyingType {
     tecINSUF_RESERVE_SELLER = 187,
     tecIMMUTABLE = 188,
     tecTOO_MANY_REMARKS = 189,
+    tecSTART_AFTER_TOO_HIGH = 190,
     tecLAST_POSSIBLE_ENTRY = 255,
 };
 

src/ripple/protocol/TxFlags.h

@@ -200,6 +200,12 @@ constexpr std::uint32_t const tfImmutable = 1;
 // Clawback flags:
 constexpr std::uint32_t const tfClawbackMask = ~tfUniversal;
 
+// CronSet Flags:
+enum CronSetFlags : uint32_t {
+    tfCronUnset = 0x00000001,
+};
+constexpr std::uint32_t const tfCronSetMask = ~(tfUniversal | tfCronUnset);
+
 // clang-format on
 
 }  // namespace ripple

src/ripple/protocol/TxFormats.h

@@ -149,6 +149,12 @@ enum TxType : std::uint16_t
     ttURITOKEN_CREATE_SELL_OFFER = 48,
     ttURITOKEN_CANCEL_SELL_OFFER = 49,
 
+    /* A pseudo-txn alarm signal for invoking a hook, emitted by validators after alarm set conditions are met */
+    ttCRON = 92,
+
+    /* Sechedule an alarm for later */
+    ttCRON_SET = 93,
+
     /* A note attaching transactor that allows the owner or issuer (on a object by object basis) to attach remarks */
     ttREMARKS_SET = 94,
 

src/ripple/protocol/impl/Feature.cpp

@@ -479,6 +479,7 @@ REGISTER_FEATURE(Clawback,                      Supported::yes, VoteBehavior::De
 REGISTER_FIX    (fixProvisionalDoubleThreading, Supported::yes, VoteBehavior::DefaultYes);
 REGISTER_FEATURE(DeepFreeze,                    Supported::yes, VoteBehavior::DefaultNo);
 REGISTER_FEATURE(IOUIssuerWeakTSH,              Supported::yes, VoteBehavior::DefaultNo);
+REGISTER_FEATURE(Cron,                          Supported::yes, VoteBehavior::DefaultNo);
 REGISTER_FIX    (fixInvalidTxFlags,             Supported::yes, VoteBehavior::DefaultYes);
 
 // The following amendments are obsolete, but must remain supported

src/ripple/protocol/impl/Indexes.cpp

@@ -72,6 +72,7 @@ enum class LedgerNameSpace : std::uint16_t {
     URI_TOKEN = 'U',
     IMPORT_VLSEQ = 'I',
     UNL_REPORT = 'R',
+    CRON = 'A',
 
     // No longer used or supported. Left here to reserve the space
     // to avoid accidental reuse.
@@ -443,6 +444,51 @@ uritoken(AccountID const& issuer, Blob const& uri)
             LedgerNameSpace::URI_TOKEN, issuer, Slice{uri.data(), uri.size()})};
 }
 
+// Constructs an ordered CRON keylet (32 bytes):
+//   [8-byte namespace][4-byte timestamp (big-endian, seconds)][20-byte
+//   AccountID]
+//
+// Properties
+// - Namespacing: first 8 bytes are the most-significant bytes of
+// indexHash(LedgerNameSpace::CRON).
+// - Uniqueness (per ts,acct): exactly ONE cron per (timestamp, AccountID).
+// Insert is upsert (last-write-wins).
+//   This is fine because we only ever allow one cron per account at a time—if
+//   the same (ts,acct) is written, it’s simply an update to that single entry
+//   (idempotent; no duplicate leaves).
+// - Iteration order: chronological by timestamp (BE), then by raw AccountID
+// bytes.
+//   NOTE: raw AccountID ordering may bias priority; consider hashing AccountID
+//   for uniform per-timestamp spread.
+// - Expected accidental prefix collisions (foreign objects sharing the 8-byte
+// namespace): n / 2^64,
+//   assuming uniform high-64-bit distribution of other objects.
+//   Examples: 100M → ~5.4e-12, 1B → ~5.4e-11, 10B → ~5.4e-10, 100B → ~5.4e-9
+//   (negligible).
+Keylet
+cron(uint32_t timestamp, AccountID const& id)
+{
+    static const uint256 ns = indexHash(LedgerNameSpace::CRON);
+
+    uint8_t h[32];
+
+    // first 8 bytes are the namespacing
+    std::memcpy(h, ns.data(), 8);
+
+    // next 4 bytes are the timestamp in BE
+    h[8] = static_cast<uint8_t>((timestamp >> 24) & 0xFFU);
+    h[9] = static_cast<uint8_t>((timestamp >> 16) & 0xFFU);
+    h[10] = static_cast<uint8_t>((timestamp >> 8) & 0xFFU);
+    h[11] = static_cast<uint8_t>((timestamp >> 0) & 0xFFU);
+
+    const uint256 accHash = indexHash(LedgerNameSpace::CRON, timestamp, id);
+
+    // final 20 bytes are account ID
+    std::memcpy(h + 12, accHash.cdata(), 20);
+
+    return {ltCRON, uint256::fromVoid(h)};
+}
+
 }  // namespace keylet
 
 }  // namespace ripple

src/ripple/protocol/impl/LedgerFormats.cpp

@@ -68,6 +68,7 @@ LedgerFormats::LedgerFormats()
             {sfGovernanceMarks,      soeOPTIONAL},
             {sfAccountIndex,         soeOPTIONAL},
             {sfTouchCount,           soeOPTIONAL},
+            {sfCron,                 soeOPTIONAL},
         },
         commonFields);
 
@@ -366,6 +367,16 @@ LedgerFormats::LedgerFormats()
         },
         commonFields);
 
+    add(jss::Cron,
+        ltCRON,
+        {
+            {sfOwner,                soeREQUIRED},
+            {sfDelaySeconds,         soeREQUIRED},
+            {sfRepeatCount,          soeREQUIRED},
+            {sfOwnerNode,            soeREQUIRED},
+        },
+        commonFields);
+
     // clang-format on
 }
 

src/ripple/protocol/impl/SField.cpp

@@ -157,6 +157,9 @@ CONSTRUCT_TYPED_SFIELD(sfLockCount,             "LockCount",            UINT32,
 
 CONSTRUCT_TYPED_SFIELD(sfFirstNFTokenSequence,  "FirstNFTokenSequence", UINT32,    50);
 
+CONSTRUCT_TYPED_SFIELD(sfStartAfter,            "StartAfter",           UINT32,    93);
+CONSTRUCT_TYPED_SFIELD(sfRepeatCount,           "RepeatCount",          UINT32,    94);
+CONSTRUCT_TYPED_SFIELD(sfDelaySeconds,          "DelaySeconds",         UINT32,    95);
 CONSTRUCT_TYPED_SFIELD(sfXahauActivationLgrSeq, "XahauActivationLgrSeq",UINT32,    96);
 CONSTRUCT_TYPED_SFIELD(sfImportSequence,        "ImportSequence",       UINT32,    97);
 CONSTRUCT_TYPED_SFIELD(sfRewardTime,            "RewardTime",           UINT32,    98);
@@ -239,6 +242,7 @@ CONSTRUCT_TYPED_SFIELD(sfGovernanceFlags,       "GovernanceFlags",      UINT256,
 CONSTRUCT_TYPED_SFIELD(sfGovernanceMarks,       "GovernanceMarks",      UINT256,   98);
 CONSTRUCT_TYPED_SFIELD(sfEmittedTxnID,          "EmittedTxnID",         UINT256,   97);
 CONSTRUCT_TYPED_SFIELD(sfHookCanEmit,           "HookCanEmit",          UINT256,   96);
+CONSTRUCT_TYPED_SFIELD(sfCron,                  "Cron",                 UINT256,   95);
 
 // currency amount (common)
 CONSTRUCT_TYPED_SFIELD(sfAmount,                "Amount",               AMOUNT,     1);

src/ripple/protocol/impl/STTx.cpp

@@ -615,7 +615,7 @@ isPseudoTx(STObject const& tx)
 
     auto tt = safe_cast<TxType>(*t);
     return tt == ttAMENDMENT || tt == ttFEE || tt == ttUNL_MODIFY ||
-        tt == ttEMIT_FAILURE || tt == ttUNL_REPORT;
+        tt == ttEMIT_FAILURE || tt == ttUNL_REPORT || tt == ttCRON;
 }
 
 }  // namespace ripple

src/ripple/protocol/impl/TER.cpp

@@ -94,6 +94,7 @@ transResults()
         MAKE_ERROR(tecINSUF_RESERVE_SELLER,          "The seller of an object has insufficient reserves, and thus cannot complete the sale."),
         MAKE_ERROR(tecIMMUTABLE,                     "The remark is marked immutable on the object, and therefore cannot be updated."),
         MAKE_ERROR(tecTOO_MANY_REMARKS,              "The number of remarks on the object would exceed the limit of 32."),
+        MAKE_ERROR(tecSTART_AFTER_TOO_HIGH,          "The proposed StartAfter time is greater than one year away."),
         MAKE_ERROR(tefALREADY,                     "The exact transaction was already in this ledger."),
         MAKE_ERROR(tefBAD_ADD_AUTH,                "Not authorized to add account."),
         MAKE_ERROR(tefBAD_AUTH,                    "Transaction's public key is not authorized."),

src/ripple/protocol/impl/TxFormats.cpp

@@ -472,6 +472,23 @@ TxFormats::TxFormats()
             {sfTicketSequence, soeOPTIONAL},
         },
         commonFields);
+
+    add(jss::Cron,
+        ttCRON,
+        {
+            {sfOwner, soeREQUIRED},
+            {sfLedgerSequence, soeREQUIRED},
+        },
+        commonFields);
+
+    add(jss::CronSet,
+        ttCRON_SET,
+        {
+            {sfDelaySeconds, soeOPTIONAL},
+            {sfRepeatCount, soeOPTIONAL},
+            {sfStartAfter, soeOPTIONAL},
+        },
+        commonFields);
 }
 
 TxFormats const&

src/ripple/protocol/jss.h

@@ -51,14 +51,16 @@ JSS(Amendments);     // ledger type.
 JSS(Amount);         // in: TransactionSign; field.
 JSS(Authorize);      // field
 JSS(Blob);
-JSS(Check);              // ledger type.
-JSS(CheckCancel);        // transaction type.
-JSS(CheckCash);          // transaction type.
-JSS(CheckCreate);        // transaction type.
-JSS(ClaimReward);        // transaction type.
-JSS(Clawback);           // transaction type.
-JSS(ClearFlag);          // field.
-JSS(CreateCode);         // field.
+JSS(Check);        // ledger type.
+JSS(CheckCancel);  // transaction type.
+JSS(CheckCash);    // transaction type.
+JSS(CheckCreate);  // transaction type.
+JSS(ClaimReward);  // transaction type.
+JSS(Clawback);     // transaction type.
+JSS(ClearFlag);    // field.
+JSS(CreateCode);   // field.
+JSS(Cron);
+JSS(CronSet);
 JSS(DeliverMin);         // in: TransactionSign
 JSS(DepositPreauth);     // transaction and ledger type.
 JSS(Destination);        // in: TransactionSign; field.

src/ripple/rpc/handlers/ServerDefinitions.cpp

@@ -423,6 +423,7 @@ private:
         addFlagsToJson<NFTokenMintFlags>(ret, "NFTokenMint");
         addFlagsToJson<NFTokenCreateOfferFlags>(ret, "NFTokenCreateOffer");
         addFlagsToJson<ClaimRewardFlags>(ret, "ClaimReward");
+        addFlagsToJson<CronSetFlags>(ret, "CronSet");
         struct FlagData
         {
             std::string name;

src/test/app/Cron_test.cpp

@@ -0,0 +1,461 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2025 XRPL Labs
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <ripple/app/ledger/LedgerMaster.h>
+#include <ripple/protocol/Feature.h>
+#include <ripple/protocol/jss.h>
+#include <test/jtx.h>
+
+namespace ripple {
+namespace test {
+struct Cron_test : public beast::unit_test::suite
+{
+    void
+    testEnabled(FeatureBitset features)
+    {
+        testcase("enabled");
+        using namespace jtx;
+        using namespace std::literals::chrono_literals;
+
+        // setup env
+        auto const alice = Account("alice");
+        auto const issuer = Account("issuer");
+
+        for (bool const withCron : {false, true})
+        {
+            auto const amend = withCron ? features : features - featureCron;
+            Env env{*this, amend};
+
+            env.fund(XRP(1000), alice, issuer);
+            env.close();
+
+            auto const expectResult =
+                withCron ? ter(tesSUCCESS) : ter(temDISABLED);
+
+            auto tx = cron::set(alice);
+            // CLAIM
+            env(cron::set(alice), cron::delay(100), fee(XRP(1)), expectResult);
+            env.close();
+        }
+    }
+
+    void
+    testFee(FeatureBitset features)
+    {
+        testcase("fee");
+        using namespace jtx;
+        using namespace std::literals::chrono_literals;
+
+        auto const alice = Account("alice");
+        Env env{*this, features | featureCron};
+
+        auto const baseFee = env.current()->fees().base;
+
+        env.fund(XRP(1000), alice);
+        env.close();
+
+        // create with RepeatCount
+        auto expected = baseFee * 2 + baseFee * 256;
+        env(cron::set(alice),
+            cron::delay(356 * 24 * 60 * 60),
+            cron::repeat(256),
+            fee(expected - 1),
+            ter(telINSUF_FEE_P));
+        env.close();
+
+        env(cron::set(alice),
+            cron::delay(356 * 24 * 60 * 60),
+            cron::repeat(256),
+            fee(expected),
+            ter(tesSUCCESS));
+        env.close();
+
+        // create with no RepeatCount
+        expected = baseFee * 2;
+        env(cron::set(alice),
+            cron::delay(356 * 24 * 60 * 60),
+            fee(expected - 1),
+            ter(telINSUF_FEE_P));
+        env.close();
+
+        env(cron::set(alice),
+            cron::delay(356 * 24 * 60 * 60),
+            fee(expected),
+            ter(tesSUCCESS));
+        env.close();
+
+        // delete
+        expected = baseFee;
+        env(cron::set(alice),
+            txflags(tfCronUnset),
+            fee(expected - 1),
+            ter(telINSUF_FEE_P));
+        env.close();
+
+        env(cron::set(alice),
+            txflags(tfCronUnset),
+            fee(expected),
+            ter(tesSUCCESS));
+        env.close();
+    }
+
+    void
+    testInvalidPreflight(FeatureBitset features)
+    {
+        testcase("invalid preflight");
+        using namespace test::jtx;
+        using namespace std::literals;
+
+        auto const alice = Account("alice");
+
+        test::jtx::Env env{
+            *this, network::makeNetworkConfig(21337), features | featureCron};
+
+        env.fund(XRP(1000), alice);
+        env.close();
+
+        //----------------------------------------------------------------------
+        // preflight
+
+        // temINVALID_FLAG
+        {
+            env(cron::set(alice), txflags(tfClose), ter(temINVALID_FLAG));
+            env(cron::set(alice),
+                txflags(tfUniversalMask),
+                ter(temINVALID_FLAG));
+        }
+
+        // temMALFORMED
+        {
+            // Invalid both DelaySeconds and RepeatCount are not specified
+            env(cron::set(alice), ter(temMALFORMED));
+
+            // Invalid DelaySeconds and RepeatCount combination
+            // (only RepeatCount specified)
+            env(cron::set(alice), cron::repeat(256), ter(temMALFORMED));
+
+            // Invalid DelaySeconds
+            env(cron::set(alice),
+                cron::delay(365 * 24 * 60 * 60 + 1),
+                cron::repeat(256),
+                ter(temMALFORMED));
+
+            // Invalid RepeatCount
+            env(cron::set(alice),
+                cron::delay(365 * 24 * 60 * 60),
+                cron::repeat(257),
+                ter(temMALFORMED));
+
+            // Invalid tfCronUnset flag
+            env(cron::set(alice),
+                cron::delay(365 * 24 * 60 * 60),
+                txflags(tfCronUnset),
+                ter(temMALFORMED));
+        }
+    }
+
+    void
+    testInvalidPreclaim(FeatureBitset features)
+    {
+        testcase("invalid preclaim");
+        using namespace test::jtx;
+        using namespace std::literals;
+
+        auto const alice = Account("alice");
+        Env env{*this, features | featureCron};
+
+        // there is no check in preclaim
+        BEAST_EXPECT(true);
+    }
+
+    void
+    testDoApply(FeatureBitset features)
+    {
+        testcase("doApply");
+        using namespace jtx;
+        using namespace std::literals::chrono_literals;
+        auto const alice = Account("alice");
+        Env env{*this, features | featureCron};
+
+        env.fund(XRP(1000), alice);
+        env.close();
+
+        auto const aliceOwnerCount = ownerCount(env, alice);
+
+        // create cron
+        env(cron::set(alice),
+            cron::delay(356 * 24 * 60 * 60),
+            cron::repeat(256),
+            fee(XRP(1)),
+            ter(tesSUCCESS));
+        env.close();
+
+        // increment owner count
+        BEAST_EXPECT(ownerCount(env, alice) == aliceOwnerCount + 1);
+
+        auto const accSle = env.le(keylet::account(alice.id()));
+        BEAST_EXPECT(accSle);
+        BEAST_EXPECT(accSle->isFieldPresent(sfCron));
+
+        auto const cronKey = keylet::child(accSle->getFieldH256(sfCron));
+        auto const cronSle = env.le(cronKey);
+        BEAST_EXPECT(cronSle);
+        BEAST_EXPECT(
+            cronSle->getFieldU32(sfDelaySeconds) == 356 * 24 * 60 * 60);
+        BEAST_EXPECT(cronSle->getFieldU32(sfRepeatCount) == 256);
+
+        // update cron
+        env(cron::set(alice),
+            cron::delay(100),
+            cron::repeat(10),
+            fee(XRP(1)),
+            ter(tesSUCCESS));
+        env.close();
+
+        // owner count does not change
+        BEAST_EXPECT(ownerCount(env, alice) == aliceOwnerCount + 1);
+
+        auto const accSle2 = env.le(keylet::account(alice.id()));
+        BEAST_EXPECT(accSle2);
+        BEAST_EXPECT(accSle2->isFieldPresent(sfCron));
+
+        // old cron sle is deleted
+        BEAST_EXPECT(!env.le(cronKey));
+
+        auto const cronKey2 = keylet::child(accSle2->getFieldH256(sfCron));
+        auto const cronSle2 = env.le(cronKey2);
+        BEAST_EXPECT(cronSle2);
+        BEAST_EXPECT(cronSle2->getFieldU32(sfDelaySeconds) == 100);
+        BEAST_EXPECT(cronSle2->getFieldU32(sfRepeatCount) == 10);
+
+        // delete cron
+        env(cron::set(alice),
+            fee(XRP(1)),
+            txflags(tfCronUnset),
+            ter(tesSUCCESS));
+        env.close();
+
+        // owner count decremented
+        BEAST_EXPECT(ownerCount(env, alice) == aliceOwnerCount);
+
+        auto const accSle3 = env.le(keylet::account(alice.id()));
+        BEAST_EXPECT(accSle3);
+        BEAST_EXPECT(!accSle3->isFieldPresent(sfCron));
+
+        // old cron sle is deleted
+        BEAST_EXPECT(!env.le(cronKey2));
+
+        // delete cron without object will succeed
+        env(cron::set(alice),
+            fee(XRP(1)),
+            txflags(tfCronUnset),
+            ter(tesSUCCESS));
+        env.close();
+    }
+
+    void
+    testCronExecution(FeatureBitset features)
+    {
+        testcase("cron execution");
+        using namespace jtx;
+        using namespace std::literals::chrono_literals;
+        auto const alice = Account("alice");
+
+        {
+            // test ttCron execution and repeatCount
+            Env env{*this, features | featureCron};
+
+            env.fund(XRP(1000), alice);
+            env.close();
+
+            auto baseTime = env.timeKeeper().now().time_since_epoch().count();
+
+            auto repeatCount = 10;
+
+            env(cron::set(alice),
+                cron::delay(100),
+                cron::repeat(repeatCount),
+                fee(XRP(1)));
+            env.close(10s);
+
+            auto lastCronKeylet =
+                keylet::child(env.le(alice)->getFieldH256(sfCron));
+
+            while (repeatCount >= 0)
+            {
+                // close ledger until 100 seconds has passed
+                while (env.timeKeeper().now().time_since_epoch().count() -
+                           baseTime <
+                       100)
+                {
+                    env.close(10s);
+                    auto txns = env.closed()->txs;
+                    auto size = std::distance(txns.begin(), txns.end());
+                    BEAST_EXPECT(size == 0);
+                }
+
+                // close after 100 seconds passed
+                env.close();
+
+                auto txns = env.closed()->txs;
+                auto size = std::distance(txns.begin(), txns.end());
+                BEAST_EXPECT(size == 1);
+                for (auto it = txns.begin(); it != txns.end(); ++it)
+                {
+                    auto const& tx = *it->first;
+                    // check pseudo txn format
+                    BEAST_EXPECT(tx.getTxnType() == ttCRON);
+                    BEAST_EXPECT(tx.getAccountID(sfAccount) == AccountID());
+                    BEAST_EXPECT(tx.getAccountID(sfOwner) == alice.id());
+                    BEAST_EXPECT(
+                        tx.getFieldU32(sfLedgerSequence) ==
+                        env.closed()->info().seq);
+                    BEAST_EXPECT(tx.getFieldAmount(sfFee) == XRP(0));
+                    BEAST_EXPECT(tx.getFieldVL(sfSigningPubKey).size() == 0);
+
+                    // check old Cron object is deleted
+                    BEAST_EXPECT(!env.le(lastCronKeylet));
+
+                    if (repeatCount > 0)
+                    {
+                        // check new Cron object
+                        auto const cronKeylet =
+                            keylet::child(env.le(alice)->getFieldH256(sfCron));
+                        auto const cronSle = env.le(cronKeylet);
+                        BEAST_EXPECT(cronSle);
+                        BEAST_EXPECT(
+                            cronSle->getFieldU32(sfDelaySeconds) == 100);
+                        BEAST_EXPECT(
+                            cronSle->getFieldU32(sfRepeatCount) ==
+                            --repeatCount);
+                        BEAST_EXPECT(
+                            cronSle->getAccountID(sfOwner) == alice.id());
+
+                        // set new base time
+                        baseTime =
+                            env.timeKeeper().now().time_since_epoch().count();
+                        lastCronKeylet = cronKeylet;
+                    }
+                    else
+                    {
+                        // after all executions, the cron object should be
+                        // deleted
+                        BEAST_EXPECT(!env.le(alice)->isFieldPresent(sfCron));
+                        BEAST_EXPECT(!env.le(lastCronKeylet));
+                        --repeatCount;  // decrement for break double loop
+                    }
+                }
+            }
+        }
+
+        {
+            // test ttCron limit in a ledger
+            Env env{*this, features | featureCron};
+            std::vector<Account> accounts;
+            accounts.reserve(300);
+            for (int i = 0; i < 300; ++i)
+            {
+                auto const& account = accounts.emplace_back(
+                    Account("account_" + std::to_string(i)));
+                accounts.emplace_back(account);
+                env.fund(XRP(10000), account);
+            }
+            env.close();
+
+            for (auto const& account : accounts)
+            {
+                env(cron::set(account), cron::delay(0), fee(XRP(1)));
+            }
+            env.close();
+
+            // proceed ledger
+            env.close();
+            {
+                auto const txns = env.closed()->txs;
+                auto size = std::distance(txns.begin(), txns.end());
+                BEAST_EXPECT(size == 128);
+                for (auto it = txns.begin(); it != txns.end(); ++it)
+                {
+                    auto const& tx = *it->first;
+                    BEAST_EXPECT(tx.getTxnType() == ttCRON);
+                }
+            }
+
+            // proceed ledger
+            env.close();
+            {
+                auto const txns = env.closed()->txs;
+                auto size = std::distance(txns.begin(), txns.end());
+                BEAST_EXPECT(size == 128);
+                for (auto it = txns.begin(); it != txns.end(); ++it)
+                {
+                    auto const& tx = *it->first;
+                    BEAST_EXPECT(tx.getTxnType() == ttCRON);
+                }
+            }
+
+            // proceed ledger
+            env.close();
+            {
+                auto const txns = env.closed()->txs;
+                auto size = std::distance(txns.begin(), txns.end());
+                BEAST_EXPECT(size == 44);
+                for (auto it = txns.begin(); it != txns.end(); ++it)
+                {
+                    auto const& tx = *it->first;
+                    BEAST_EXPECT(tx.getTxnType() == ttCRON);
+                }
+            }
+
+            // proceed ledger
+            env.close();
+            {
+                auto const txns = env.closed()->txs;
+                auto size = std::distance(txns.begin(), txns.end());
+                BEAST_EXPECT(size == 0);
+            }
+        }
+    }
+
+    void
+    testWithFeats(FeatureBitset features)
+    {
+        testEnabled(features);
+        testFee(features);
+        testInvalidPreflight(features);
+        testInvalidPreclaim(features);
+        testDoApply(features);
+
+        testCronExecution(features);
+    }
+
+public:
+    void
+    run() override
+    {
+        using namespace test::jtx;
+        auto const sa = supported_amendments();
+        testWithFeats(sa);
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(Cron, app, ripple);
+
+}  // namespace test
+}  // namespace ripple

src/test/app/MultiSign_test.cpp

@@ -1675,7 +1675,6 @@ public:
             env.fund(XRP(1000), alice);
             env.close();
 
-            bool const enabled = features[fixInvalidTxFlags];
             testcase(
                 std::string("SignerListSet flag, fix ") +
                 (withFixInvalidTxFlags ? "enabled" : "disabled"));

src/test/app/SetHookTSH_test.cpp

@@ -22,6 +22,7 @@
 #include <ripple/app/misc/HashRouter.h>
 #include <ripple/app/misc/TxQ.h>
 #include <ripple/app/tx/apply.h>
+#include <ripple/basics/StringUtilities.h>
 #include <ripple/protocol/Feature.h>
 #include <ripple/protocol/PayChan.h>
 #include <ripple/protocol/jss.h>
@@ -748,10 +749,22 @@ private:
         jtx::Env& env,
         int const& expected,
         uint64_t const& lineno)
+    {
+        auto const hashStr =
+            env.tx()->getJson(JsonOptions::none)[jss::hash].asString();
+        uint256 const txHash = uint256::fromVoid(strUnHex(hashStr)->data());
+        testTSHStrongWeak(env, txHash, expected, lineno);
+    }
+
+    void
+    testTSHStrongWeak(
+        jtx::Env& env,
+        uint256 const& txHash,
+        int const& expected,
+        uint64_t const& lineno)
     {
         Json::Value params;
-        params[jss::transaction] =
-            env.tx()->getJson(JsonOptions::none)[jss::hash];
+        params[jss::transaction] = strHex(txHash);
         auto const jrr = env.rpc("json", "tx", to_string(params));
         auto const meta = jrr[jss::result][jss::meta];
         validateTSHStrongWeak(meta, expected, lineno);
@@ -6251,6 +6264,103 @@ private:
         }
     }
 
+    // CronSet
+    // | otxn | tsh | cset |
+    // |   A  |  A  |  S   |
+    void
+    testCronSetTSH(FeatureBitset features)
+    {
+        testcase("cron set tsh");
+
+        using namespace test::jtx;
+        using namespace std::literals;
+
+        // otxn: account
+        // tsh account
+        // w/s: strong
+        for (bool const testStrong : {true, false})
+        {
+            test::jtx::Env env{
+                *this,
+                network::makeNetworkConfig(21337, "10", "1000000", "200000"),
+                features};
+
+            auto const account = Account("alice");
+            env.fund(XRP(1000), account);
+            env.close();
+
+            if (!testStrong)
+                addWeakTSH(env, account);
+
+            // set tsh hook
+            setTSHHook(env, account, testStrong);
+
+            // cron set
+            env(cron::set(account),
+                cron::delay(100),
+                cron::repeat(1),
+                fee(XRP(1)),
+                ter(tesSUCCESS));
+            env.close();
+
+            // verify tsh hook triggered
+            testTSHStrongWeak(env, tshSTRONG, __LINE__);
+        }
+    }
+
+    // | otxn | tsh | cron |
+    // |   -  |  O  |  W   |
+    void
+    testCronTSH(FeatureBitset features)
+    {
+        testcase("cron tsh");
+
+        using namespace test::jtx;
+        using namespace std::literals;
+
+        // otxn: -
+        // tsh owner
+        // w/s: weak
+        for (bool const testStrong : {true, false})
+        {
+            test::jtx::Env env{
+                *this,
+                network::makeNetworkConfig(21337, "10", "1000000", "200000"),
+                features};
+
+            auto const account = Account("alice");
+            env.fund(XRP(1000), account);
+            env.close();
+
+            // cron set
+            env(cron::set(account),
+                cron::delay(100),
+                cron::repeat(1),
+                fee(XRP(1)),
+                ter(tesSUCCESS));
+            env.close();
+
+            if (!testStrong)
+                addWeakTSH(env, account);
+
+            // set tsh hook
+            setTSHHook(env, account, testStrong);
+
+            // proceed ledger
+            env.close(100s);
+
+            // close ledger
+            env.close();
+
+            // verify tsh hook triggered
+            auto const expected = testStrong ? tshNONE : tshWEAK;
+            auto const txs = env.closed()->txs;
+            BEAST_EXPECT(std::distance(txs.begin(), txs.end()) == 1);
+            auto const tx = txs.begin()->first;
+            BEAST_EXPECT(tx->getTxnType() == ttCRON);
+            testTSHStrongWeak(env, tx->getTransactionID(), expected, __LINE__);
+        }
+    }
     void
     testEmissionOrdering(FeatureBitset features)
     {
@@ -6398,6 +6508,8 @@ private:
         testURITokenCancelSellOfferTSH(features);
         testURITokenCreateSellOfferTSH(features);
         testRemitTSH(features);
+        testCronSetTSH(features);
+        testCronTSH(features);
     }
 
     void

src/test/jtx.h

@@ -33,6 +33,7 @@
 #include <test/jtx/amount.h>
 #include <test/jtx/balance.h>
 #include <test/jtx/check.h>
+#include <test/jtx/cron.h>
 #include <test/jtx/delivermin.h>
 #include <test/jtx/deposit.h>
 #include <test/jtx/escrow.h>

src/test/jtx/cron.h

@@ -0,0 +1,74 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2025 XRPL Labs
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_TEST_JTX_CRON_H_INCLUDED
+#define RIPPLE_TEST_JTX_CRON_H_INCLUDED
+
+#include <test/jtx/Account.h>
+#include <test/jtx/Env.h>
+
+namespace ripple {
+namespace test {
+namespace jtx {
+
+/** Cron operations. */
+namespace cron {
+
+/** Set a cron. */
+Json::Value
+set(jtx::Account const& account);
+
+/** Sets the optional DelaySeconds on a JTx. */
+class delay
+{
+private:
+    uint32_t delay_;
+
+public:
+    explicit delay(uint32_t delay) : delay_(delay)
+    {
+    }
+
+    void
+    operator()(Env&, JTx& jtx) const;
+};
+
+/** Sets the optional RepeatCount on a JTx. */
+class repeat
+{
+private:
+    uint32_t repeat_;
+
+public:
+    explicit repeat(uint32_t repeat) : repeat_(repeat)
+    {
+    }
+
+    void
+    operator()(Env&, JTx& jtx) const;
+};
+
+}  // namespace cron
+
+}  // namespace jtx
+
+}  // namespace test
+}  // namespace ripple
+
+#endif  // RIPPLE_TEST_JTX_CRON_H_INCLUDED

src/test/jtx/impl/cron.cpp

@@ -0,0 +1,56 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2025 XRPL Labs
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <ripple/protocol/jss.h>
+#include <test/jtx/cron.h>
+
+namespace ripple {
+namespace test {
+namespace jtx {
+
+namespace cron {
+
+// Set a cron.
+Json::Value
+set(jtx::Account const& account)
+{
+    using namespace jtx;
+    Json::Value jv;
+    jv[jss::TransactionType] = jss::CronSet;
+    jv[jss::Account] = account.human();
+    return jv;
+}
+
+void
+delay::operator()(Env& env, JTx& jt) const
+{
+    jt.jv[sfDelaySeconds.jsonName] = delay_;
+}
+
+void
+repeat::operator()(Env& env, JTx& jt) const
+{
+    jt.jv[sfRepeatCount.jsonName] = repeat_;
+}
+
+}  // namespace cron
+
+}  // namespace jtx
+}  // namespace test
+}  // namespace ripple