Make ApplyFlags a scoped enumeration

Convert ApplyFlags to a scoped enum, drop the now-redundant `Tap`
prefix from its enumerators and replace the hand-written bitwise
operators by opting in to enum_bitops.

No functional change.

.cspell.config.yaml

@@ -103,6 +103,7 @@ words:
   - dearmor
   - decryptor
   - dedented
+  - dedup
   - deleteme
   - demultiplexer
   - deserializaton
@@ -344,6 +345,7 @@ words:
   - unambiguity
   - unauthorizes
   - unauthorizing
+  - undeserializable
   - unergonomic
   - unfetched
   - unfindable

.github/dependabot.yml

@@ -36,3 +36,18 @@ updates:
       rust-dependencies:
         patterns:
           - "*"
+
+  - package-ecosystem: uv
+    directory: /cmake/scripts/codegen
+    schedule:
+      interval: weekly
+      day: monday
+      time: "04:00"
+      timezone: Etc/GMT
+    commit-message:
+      prefix: "chore: [DEPENDABOT] "
+    target-branch: develop
+    groups:
+      codegen-dependencies:
+        patterns:
+          - "*"

.github/scripts/levelization/results/ordering.txt

@@ -62,6 +62,7 @@ libxrpl.tx > xrpl.protocol
 libxrpl.tx > xrpl.server
 libxrpl.tx > xrpl.tx
 test.app > test.jtx
+test.app > tests.libxrpl
 test.app > test.unit_test
 test.app > xrpl.basics
 test.app > xrpl.config
@@ -174,7 +175,6 @@ test.server > xrpl.basics
 test.server > xrpl.config
 test.server > xrpld.app
 test.server > xrpld.core
-test.server > xrpld.rpc
 test.server > xrpl.json
 test.server > xrpl.protocol
 test.server > xrpl.server

.github/workflows/cargo-audit.yml

@@ -8,6 +8,7 @@ on:
     branches:
       - "develop"
       - "release/*"
+      - "staging/*"
     paths:
       - "crates/**/Cargo.toml"
       - "crates/Cargo.lock"

.github/workflows/on-pr.yml

@@ -243,7 +243,7 @@ jobs:
       - should-run
       - build-test
     # Only run when committing to a PR that targets a release branch.
-    if: ${{ github.repository == 'XRPLF/rippled' && needs.should-run.outputs.go == 'true' && github.event_name == 'pull_request' && startsWith(github.event.pull_request.base.ref, 'release') }}
+    if: ${{ github.repository == 'XRPLF/rippled' && needs.should-run.outputs.go == 'true' && github.event_name == 'pull_request' && startsWith(github.event.pull_request.base.ref, 'release/') }}
     uses: ./.github/workflows/reusable-upload-recipe.yml
     secrets:
       remote_username: ${{ secrets.NEXUS_REMOTE_USERNAME }}

.github/workflows/on-trigger.yml

@@ -1,14 +1,16 @@
 # This workflow runs all workflows to build and test the code on various Linux
 # flavors, as well as on MacOS and Windows, on a scheduled basis, on merge into
-# the 'develop' or 'release*' branches, or when requested manually. Upon pushes
-# to the develop branch it also uploads the libxrpl recipe to the Conan remote.
+# the 'develop', 'release/*' or 'staging/*' branches, or when requested
+# manually. Upon pushes to the develop branch, it also uploads the libxrpl
+# recipe to the Conan remote.
 name: Trigger
 
 on:
   push:
     branches:
       - "develop"
-      - "release*"
+      - "release/*"
+      - "staging/*"
     paths:
       # These paths are unique to `on-trigger.yml`.
       - ".github/workflows/on-trigger.yml"
@@ -62,9 +64,9 @@ on:
   workflow_dispatch:
 
 concurrency:
-  # When a PR is merged into the develop branch it will be assigned a unique
+  # When a PR is merged into the develop branch, it will be assigned a unique
   # group identifier, so execution will continue even if another PR is merged
-  # while it is still running. In all other cases the group identifier is shared
+  # while it is still running. In all other cases, the group identifier is shared
   # per branch, so that any in-progress runs are cancelled when a new commit is
   # pushed.
   group: ${{ github.workflow }}-${{ github.event_name == 'push' && github.ref == 'refs/heads/develop' && github.sha || github.ref }}
@@ -98,7 +100,7 @@ jobs:
       # However, we do not enable ccache for events targeting a release branch,
       # to protect against the rare case that the output produced by ccache is
       # not identical to a regular compilation.
-      ccache_enabled: ${{ github.repository_owner == 'XRPLF' && !startsWith(github.ref, 'refs/heads/release') }}
+      ccache_enabled: ${{ github.repository_owner == 'XRPLF' && !startsWith(github.ref, 'refs/heads/release/') }}
       os: ${{ matrix.os }}
     secrets:
       CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}

.github/workflows/pre-commit.yml

@@ -8,7 +8,8 @@ on:
   push:
     branches:
       - "develop"
-      - "release*"
+      - "release/*"
+      - "staging/*"
   workflow_dispatch:
 
 jobs:

.github/workflows/reusable-clang-tidy.yml

@@ -123,13 +123,19 @@ jobs:
 
       - name: Fix style
         if: ${{ steps.files_changed.outcome != 'success' }}
+        # pre-commit installs every hook's environment, even for hooks that match
+        # no files, and node-based hooks need libatomic, which this image lacks.
+        # Exit code 1 just means hooks modified files or found issues.
+        env:
+          SKIP: prettier,cspell
         run: |
-          pre-commit run --all-files || true
+          git add --update
+          pre-commit run || [ $? -eq 1 ]
 
       - name: Generate git diff
         if: ${{ steps.files_changed.outcome != 'success' }}
         run: |
-          git diff | tee "${DIFF_FILE}"
+          git diff HEAD | tee "${DIFF_FILE}"
 
       - name: Upload clang-tidy diff output
         if: ${{ github.event.repository.visibility == 'public' && steps.files_changed.outcome != 'success' }}

.github/workflows/reusable-package-test-install.yml

@@ -95,11 +95,15 @@ jobs:
           apt-get update -qq
           apt-get install -y "./${PACKAGE}"
 
+      # Rocky Linux and AlmaLinux pick a mirror from a mirrorlist, and now and
+      # then get one that serves the repository metadata at a few hundred kB/s,
+      # which alone outlasts the job's timeout. dnf only abandons a mirror below
+      # 1000 B/s for 30 s, so raise that floor to fail over to the next one fast.
       - name: Install the RPM
         if: ${{ inputs.package_type == 'rpm' }}
         env:
           PACKAGE: ${{ steps.find.outputs.package }}
-        run: dnf install -y "./${PACKAGE}"
+        run: dnf install -y --setopt=minrate=1M --setopt=timeout=10 "./${PACKAGE}"
 
       - name: Run xrpld
         run: xrpld --version

API-CHANGELOG.md

@@ -22,15 +22,6 @@ API version 2 is available in `xrpld` version 2.0.0 and later. See [API-VERSION-
 
 This version is supported by all `xrpld` versions. For WebSocket and HTTP JSON-RPC requests, it is currently the default API version used when no `api_version` is specified.
 
-## Unreleased
-
-### Bugfixes
-
-- A request echoed back in an error reply now has every credential-bearing field masked: `admin_password`, `admin_user`, `passphrase`, `password`, `secret`, `seed`, `seed_hex`, `url_password`, `url_username` and `username`. Nesting no longer matters, so a credential inside `params` is masked too. The same masking is applied to every request and reply written to the log, and it covers six further names that only a reply carries: `master_key`, `master_seed`, `master_seed_hex`, `validation_key`, `validation_private_key` and `validation_seed`, which is how `wallet_propose` and `validation_create` used to write a live private key to the log. A request or reply written to the log is truncated at 10,000 characters. An `[rpc_startup]` line that does not parse is reported by its position in the section and the parser's message, never by its text, and no command runs for it.
-- The command line client no longer prints a credential the operator did not type. A failing command echoes the request it built under `request_sent`, which carries the `admin_password` the client copies out of `[port_rpc]` in the config, so `./xrpld account_info rBogus` printed that password to stdout and into any captured output. `request_sent` is now masked. The `rpc` member beside it, which echoes the arguments as they were typed, is unchanged. The command line client also no longer writes an unparsed `json` or `ripple_path_find` argument to its trace log before parsing it, where a `secret` inside that argument could not be masked; it logs the parsed request instead, masked. The reply it receives is logged the same way, parsed and masked, where the raw body was written before, a `validation_create` answer included.
-- A WebSocket frame that does not parse, or exceeds the request size limit, is answered `{"type": "error", "error": "jsonInvalid", "size": <bytes>}`. The frame's body is reported by size rather than echoed back in a `value` member, since a body that does not parse has no fields to mask. A client that read `value` gets `size` instead.
-- Four error codes that named no HTTP status of their own, and so answered 200 on a reply reporting an error, now name one: `actMalformed`, `alreadyMultisig` and `alreadySingleSig` answer 400, and `actNotFound` answers 404. **No shipped envelope reports these four.** A request sending `ripplerpc: "3.0"` still receives 200 for all four, as it always has, so `account_info` on a malformed account or one the ledger does not hold answers 200 exactly as before.
-
 ## XRP Ledger server version 3.5.0
 
 Version 3.5.0 is not yet released.
@@ -44,6 +35,9 @@ Version 3.5.0 is not yet released.
 
 - `channel_authorize`: The `channel_id` field now returns an `invalidParams` error if the value is not a string. [#7582](https://github.com/XRPLF/rippled/pull/7582)
 - `channel_verify`: The `channel_id` and `signature` fields now return an `invalidParams` error if the value is not a string. [#7582](https://github.com/XRPLF/rippled/pull/7582)
+- `account_currencies`, `account_nfts`, `account_offers`: A request with more than one problem may now report a different one of them. An invalid `ledger_hash` or `ledger_index` is reported before an invalid or missing `account`. An invalid `limit` or `marker` is reported before `lgrNotFound` or `actNotFound`, and for `account_offers` also before `actMalformed`. A request with a single problem returns the same error as before. [#8561](https://github.com/XRPLF/rippled/pull/8561)
+- `deposit_authorized`: A `credentials` entry that is all zeros (for example `"0"` or 64 `0` characters) now returns a `badCredentials` error instead of looking up a credential that can never exist.
+- `account_info`, `account_lines`, `account_channels`: A request with more than one problem may now report a different one of them. An invalid `ledger_hash` or `ledger_index` is reported before a missing or invalid `account`, or `ident` for `account_info`. For `account_lines`, a `peer` that is not a string, or an invalid `limit` or `marker`, is reported before `lgrNotFound`, `actNotFound` or a malformed `account`, and an invalid `limit` or `marker` also before a malformed `peer`. For `account_channels`, a malformed `account` is reported before `lgrNotFound`, and an invalid `destination_account`, `limit` or `marker` before `lgrNotFound` or `actNotFound`. A request with a single problem returns the same error as before. [#8573](https://github.com/XRPLF/rippled/pull/8573)
 
 ### Bugfixes in 3.5.0
 

BUILD.md

@@ -2,33 +2,12 @@
 | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | These instructions assume you have a C++ development environment ready with Git, Python, Conan, CMake, and a C++ compiler. For help setting one up on Linux, macOS, or Windows, [see this guide](./docs/build/environment.md).<br><br>These instructions also assume a basic familiarity with Conan and CMake. If you are unfamiliar with Conan, you can read our [crash course](./docs/build/conan.md) or the official [Getting Started][conan-getting-started] walkthrough. |
 
-## Minimum Requirements
+## Supported platforms
 
-For the hardware needed to run a node, see
-[System Requirements](https://xrpl.org/system-requirements.html).
-
-For the software needed to build xrpld, see the
-[environment setup guide](./docs/build/environment.md).
-
-## Operating Systems
-
-### Linux
-
-The Ubuntu Linux distribution has received the highest level of quality
-assurance, testing, and support. We also support Red Hat and use Debian
-internally.
-Our Linux CI tooling is distro-independent and uses a Nix-based environment, so it should be possible to build on other Linux distributions as well, although we have not tested them.
-
-### macOS
-
-Many `xrpld` engineers use macOS for development.
-The minimum supported version is macOS 15 (Sequoia).
-CI testing is done in macOS 26 (Tahoe), but the build defaults `CMAKE_OSX_DEPLOYMENT_TARGET` to 15.
-
-### Windows
-
-Windows is used by some engineers for development only, and is not recommended
-for production use.
+Building and testing are supported on Linux, macOS, and (best effort) Windows;
+see [Supported development platforms](./docs/build/environment.md#supported-development-platforms).
+Running `xrpld` is officially supported on Linux only;
+see [Requirements](./docs/install.md#requirements).
 
 ## Steps
 

CMakeLists.txt

@@ -42,7 +42,7 @@ if(is_gcc)
     # GCC-specific fixes
     add_compile_options(-Wno-unknown-pragmas -Wno-subobject-linkage)
     # -Wno-subobject-linkage can be removed when we upgrade GCC version to at least 13.3
-elseif(is_clang)
+elseif(is_any_clang)
     # Clang-specific fixes
     add_compile_options(-Wno-unknown-warning-option) # Ignore unknown warning options
 elseif(is_msvc)

CONTRIBUTING.md

@@ -332,7 +332,7 @@ This ensures that configuration changes don't introduce new warnings across the
 
 ### Installing clang-tidy
 
-See the [environment setup guide](./docs/build/environment.md#clang-tidy) for how to get clang-tidy.
+The [Nix development shell](./docs/build/nix.md) provides `clang-tidy` at the [tested version](./docs/build/environment.md#tested-compiler-versions).
 
 ### Running clang-tidy locally
 

RELEASING.md

@@ -34,7 +34,7 @@ so tools can filter them and protection rules can target `release/*` and `stagin
 - **Branches only move forward.**
   `develop`, `staging/X.Y.x`, and `release/X.Y.x` are never rewritten.
 - **Cherry-picking only goes from `develop` to a staging branch**,
-  for fixes that must get into a release after the code freeze
+  for fixes that must get into a release after the [code freeze](#release-candidates)
   (see [Emergency Fixes From `develop`](#emergency-fixes-from-develop)).
 - **Security fixes are prepared privately and published with the release that contains them**,
   so vulnerabilities are not disclosed prematurely.
@@ -49,6 +49,7 @@ develop                            staging/X.Y.x & release/X.Y.x
    │
    ├── Tag: X.Y.0-b1
    ├── Tag: X.Y.0-bN
+   │  (2 weeks before rc1: freeze on large changes starts)
    ├── Tag: X.Y.0-rc1 ───────────────┐ (branches created)
    │                                 │
    │  (development continues)        ├── Fixes
@@ -75,16 +76,20 @@ develop                            staging/X.Y.x & release/X.Y.x
 3. **Branches:** `staging/X.Y.x` and `release/X.Y.x` are created from `develop`
    at the commit tagged `X.Y.0-rc1`.
    The first RC also kicks off the QE process.
-4. **Code freeze:** No new features or unrelated changes are pulled from `develop`
-   into `staging/X.Y.x` or `release/X.Y.x`.
-   Only critical stabilization fixes go into the line.
-5. **No large changes on `develop`:** Until `X.Y.0` is [merged back](#merging-back-into-develop),
-   large changes (e.g., big refactors, moving or renaming many files, mass reformatting)
-   are not merged into `develop`,
-   so that fixes on the line and the merge back don't run into conflicts.
+
+### Freeze on Large Changes
+
+From two weeks before `X.Y.0-rc1` until `X.Y.0` is [merged back](#merging-back-into-develop),
+large changes (e.g., big refactors, moving or renaming many files, mass reformatting)
+are not merged into `develop`.
 
 ### Release Candidates
 
+After branching, the line is in code freeze:
+no new features or unrelated changes are pulled from `develop`
+into `staging/X.Y.x` or `release/X.Y.x`.
+Only critical stabilization fixes go into the line.
+
 1. Fixes are developed against `staging/X.Y.x`.
 2. When ready, a new RC is created on `staging/X.Y.x`,
    and `release/X.Y.x` is fast-forwarded to it.
@@ -106,7 +111,8 @@ one right after the other.
 2. `release/X.Y.x` is fast-forwarded to `staging/X.Y.x`,
    and the release is tagged on it.
 3. The release is immediately [merged back into `develop`](#merging-back-into-develop).
-   For a major-minor release, this lifts the freeze on large changes in `develop`.
+   For a major-minor release, this lifts the [freeze on large changes](#freeze-on-large-changes)
+   in `develop`.
 
 ### Merging Back Into `develop`
 
@@ -127,7 +133,7 @@ After the merge, `git log develop..<tag>` must be empty.
 ### Emergency Fixes From `develop`
 
 If a commit was merged to `develop`
-and needs to be included in a release after the code freeze:
+and needs to be included in a release after the [code freeze](#release-candidates):
 
 1. Create a PR that cherry-picks the commit onto `staging/X.Y.x`.
 2. Leave `develop` as it is, with no reverts.

cfg/xrpld-example.cfg

@@ -1360,6 +1360,39 @@
 #       Example:
 #           owner_reserve = 200000      # 0.2 XRP
 #
+#   gas_limit = <gas>
+#
+#       The gas limit is the maximum amount of gas that can be
+#       consumed by a single transaction. The gas limit is used to prevent
+#       transactions from consuming too many resources.
+#
+#       If this parameter is unspecified, xrpld will use an internal
+#       default. Don't change this without understanding the consequences.
+#
+#       Example:
+#           gas_limit = 1000000      # 1 million gas
+#
+#   bytecode_size_limit = <bytes>
+#
+#       The bytecode size limit is the maximum size of a WASM extension in
+#       bytes. The size limit is used to prevent extensions from consuming
+#       too many resources.
+#
+#       If this parameter is unspecified, xrpld will use an internal
+#       default. Don't change this without understanding the consequences.
+#
+#       Example:
+#           bytecode_size_limit = 100000      # 100 kb
+#
+#   gas_price = <micro-drops>
+#
+#       The gas price is the conversion between WASM gas and its price in drops.
+#
+#       If this parameter is unspecified, xrpld will use an internal
+#       default. Don't change this without understanding the consequences.
+#
+#       Example:
+#           gas_price = 1000000      # 1 drop per gas
 #-------------------------------------------------------------------------------
 #
 # 9. Misc Settings

cmake/CompilationEnv.cmake

@@ -9,13 +9,21 @@ include_guard(GLOBAL)
 # --------------------------------------------------------------------
 # Compiler detection (C++)
 # --------------------------------------------------------------------
-set(is_clang FALSE)
+# is_any_clang is true for both LLVM Clang and AppleClang. Their version numbers
+# and feature sets differ, so use is_llvm_clang or is_apple_clang when it matters.
+set(is_any_clang FALSE)
+set(is_llvm_clang FALSE)
+set(is_apple_clang FALSE)
 set(is_gcc FALSE)
 set(is_msvc FALSE)
 set(is_xcode FALSE)
 
-if(CMAKE_CXX_COMPILER_ID MATCHES ".*Clang") # Clang or AppleClang
-    set(is_clang TRUE)
+if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    set(is_any_clang TRUE)
+    set(is_llvm_clang TRUE)
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+    set(is_any_clang TRUE)
+    set(is_apple_clang TRUE)
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     set(is_gcc TRUE)
 elseif(MSVC)

cmake/XrplCompiler.cmake

@@ -130,7 +130,7 @@ else()
         INTERFACE
             -Wall
             -Wdeprecated
-            $<$<BOOL:${is_clang}>:-Wno-deprecated-declarations>
+            $<$<BOOL:${is_any_clang}>:-Wno-deprecated-declarations>
             $<$<BOOL:${wextra}>:-Wextra
             -Wno-unused-parameter>
             $<$<BOOL:${werr}>:-Werror>
@@ -177,7 +177,7 @@ else()
     if(
         is_nix_compiler
         AND is_linux
-        AND is_clang
+        AND is_any_clang
         AND CMAKE_CXX_FLAGS MATCHES "stdlib=libstdc"
     )
         string(
@@ -204,7 +204,10 @@ if(voidstar)
             "Antithesis instrumentation requires Linux, aborting..."
         )
     elseif(
-        NOT (is_clang AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 16.0)
+        NOT (
+            is_llvm_clang
+            AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 16.0
+        )
     )
         message(
             FATAL_ERROR

cmake/XrplCore.cmake

@@ -296,7 +296,16 @@ if(xrpld)
         OUT_VAR rpcspec_instantiations
         VALUE_TYPE "::json::Value"
         VIEW_HEADER "xrpld/rpc/detail/JsonObjectView.hpp"
-        HANDLERS book_changes ledger transaction_entry
+        HANDLERS
+            account_channels
+            account_currencies
+            account_info
+            account_lines
+            account_nfts
+            account_offers
+            book_changes
+            ledger
+            transaction_entry
     )
     target_sources(xrpld PRIVATE ${rpcspec_instantiations})
 

cmake/XrplSanitizers.cmake

@@ -58,7 +58,7 @@ target_link_options(common INTERFACE ${sanitizers_linker_flags})
 # This module appends -fsanitize-ignorelist=<path> for Clang builds.
 # The ignorelist path contains CMAKE_SOURCE_DIR, so it must be set here, rather than in the Conan profile.
 # GCC does not support -fsanitize-ignorelist.
-if(is_clang)
+if(is_any_clang)
     set(ignorelist_path
         "${CMAKE_SOURCE_DIR}/sanitizers/suppressions/sanitizer-ignorelist.txt"
     )

cmake/XrplSanity.cmake

@@ -23,11 +23,8 @@ if(NOT is_multiconfig)
     endif()
 endif()
 
-if(is_clang) # both Clang and AppleClang
-    if(
-        "${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang"
-        AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 16.0
-    )
+if(is_llvm_clang)
+    if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 16.0)
         message(FATAL_ERROR "This project requires clang 16 or later")
     endif()
 elseif(is_gcc)

cmake/XrplSettings.cmake

@@ -62,11 +62,11 @@ if(unity)
     set(CMAKE_UNITY_BUILD ON CACHE BOOL "Do a unity build")
 endif()
 
-if(is_clang AND is_linux)
+if(is_llvm_clang AND is_linux)
     option(voidstar "Enable Antithesis instrumentation." OFF)
 endif()
 
-if(is_gcc OR is_clang)
+if(is_gcc OR is_any_clang)
     include(ProcessorCount)
     ProcessorCount(PROCESSOR_COUNT)
 
@@ -125,7 +125,7 @@ else()
     set(use_mold OFF CACHE BOOL "mold linker, linux only" FORCE)
 endif()
 
-if(is_clang)
+if(is_any_clang)
     option(use_lld "enables detection of lld linker" ON)
 else()
     set(use_lld OFF CACHE BOOL "try lld linker, clang only" FORCE)

cmake/scripts/codegen/requirements.in

@@ -7,7 +7,7 @@
 pcpp>=1.30
 
 # Parser combinator library - used to parse the macro DSL
-pyparsing>=3.0.0
+pyparsing>=3.3.3
 
 # Template engine - used to generate C++ code from templates
-Mako>=1.2.2
+Mako>=1.4.2

cmake/scripts/codegen/requirements.txt

@@ -1,8 +1,8 @@
 # This file was autogenerated by uv via the following command:
 #    uv pip compile requirements.in --generate-hashes --output-file requirements.txt
-mako==1.3.12 \
-    --hash=sha256:8f61569480282dbf557145ce441e4ba888be453c30989f879f0d652e39f53ea9 \
-    --hash=sha256:9f778e93289bd410bb35daadeb4fc66d95a746f0b75777b942088b7fd7af550a
+mako==1.4.3 \
+    --hash=sha256:723296007c870bfd6b3f0c3230dba7198096e5269297ebf5e4eff9e7ffa39d4f \
+    --hash=sha256:cd6537fe88d5fec315c55c2f8529bc4ce7a9a352ad7db3eeaa6a66e2dd4ec37a
     # via -r requirements.in
 markupsafe==3.0.3 \
     --hash=sha256:0303439a41979d9e74d18ff5e2dd8c43ed6c6001fd40e5bf2e43f7bd9bbc523f \
@@ -99,7 +99,7 @@ pcpp==1.30 \
     --hash=sha256:05fe08292b6da57f385001c891a87f40d6aa7f46787b03e8ba326d20a3297c6e \
     --hash=sha256:5af9fbce55f136d7931ae915fae03c34030a3b36c496e72d9636cedc8e2543a1
     # via -r requirements.in
-pyparsing==3.3.2 \
-    --hash=sha256:850ba148bd908d7e2411587e247a1e4f0327839c40e2e5e6d05a007ecc69911d \
-    --hash=sha256:c777f4d763f140633dcb6d8a3eda953bf7a214dc4eff598413c070bcdc117cbc
+pyparsing==3.3.3 \
+    --hash=sha256:928ae7e20211f3b6f3915a72f06a0cfd29ab9d24279dd6346b6b1a7146397d36 \
+    --hash=sha256:ece8c00a69cf01b45d0b1dedabb469c90d8caf996d4fda40f147627a122849a4
     # via -r requirements.in

conan.lock

@@ -3,7 +3,7 @@
     "requires": [
         "zlib/1.3.2#1cb806da49011867778ffb6ac7190fcb%1782392402.122708",
         "xxhash/0.8.3#681d36a0a6111fc56e5e45ea182c19cc%1782392402.420688",
-        "xrpl-rpc-spec/0.1.21#d536f87a2ae7d313452746cfa3ac4404%1790869005.122975",
+        "xrpl-rpc-spec/0.1.25#2daa763e2d86ccc4ad0a0fa4d1983e9f%1791907455.579992",
         "sqlite3/3.53.0#324ada52333108388a9a6108bfa96734%1782392403.185447",
         "soci/4.0.3#e726491a03468795453f7c83fc924a96%1782392402.679521",
         "snappy/1.1.10#968fef506ff261592ec30c574d4a7809%1782307151.633168",

conanfile.py

@@ -40,7 +40,7 @@ class Xrpl(ConanFile):
         "nudb/2.0.9",
         "openssl/3.6.3",
         "soci/4.0.3",
-        "xrpl-rpc-spec/0.1.21",
+        "xrpl-rpc-spec/0.1.25",
         "zlib/1.3.2",
     ]
 

docs/build/environment.md

@@ -4,6 +4,18 @@ This document explains how to set one up.
 
 [BUILD.md]: ../../BUILD.md
 
+## Supported development platforms
+
+- **Linux**: the [Nix development shell](./nix.md),
+  which provides the same toolchain CI uses on any distribution.
+- **macOS** 15 (Sequoia) or newer: the [Nix development shell](./nix.md),
+  or the system [Apple Clang](#macos-apple-clang).
+  CI runs on macOS 26 (Tahoe), but the build defaults `CMAKE_OSX_DEPLOYMENT_TARGET` to 15.
+- **Windows**: best effort, see [Windows](#windows).
+
+For the platforms supported for running `xrpld`,
+see [Requirements](../install.md#requirements).
+
 ## Tested compiler versions
 
 `xrpld` is built in the **C++23** dialect by default, so your toolchain has to
@@ -35,20 +47,16 @@ compiler building. Treat support for anything outside the table as best-effort.
 
 ## Required tools
 
-Besides a compiler, building `xrpld` requires:
-
-| Tool                                        | Minimum version |
-| ------------------------------------------- | --------------- |
-| [Git](https://git-scm.com/downloads)        | any recent      |
-| [Python](https://www.python.org/downloads/) | 3.11            |
-| [Conan](https://conan.io/downloads.html)    | 2.17            |
-| [CMake](https://cmake.org/download/)        | 3.16            |
+Besides a compiler, building `xrpld` requires
+[Git](https://git-scm.com/downloads),
+[Python](https://www.python.org/downloads/),
+[Conan](https://conan.io/downloads.html),
+and [CMake](https://cmake.org/download/).
+Building with `-Drust=ON` additionally requires a Rust toolchain,
+see [Rust](#rust).
 
 On Linux and macOS, the [Nix development shell](./nix.md) provides all of them
-(see below). On Windows they have to be installed manually.
-
-Building with `-Drust=ON` additionally requires a Rust toolchain, see
-[Rust](#rust). A default build does not, so it is not in the table above.
+at the versions CI uses, recorded in [`nix/check-tools/`](../../nix/check-tools).
 
 Once they are in place, verify that everything is installed and runnable with:
 
@@ -58,60 +66,19 @@ Once they are in place, verify that everything is installed and runnable with:
 
 ## Linux and macOS
 
-The **recommended way** to get a development environment on Linux and macOS is
-the Nix development shell. It provides the exact tooling used in CI — `git`,
-`python`, `conan`, `cmake`, `clang-tidy`, `clang-format`, and everything else —
-with a single command and without installing anything system-wide:
+Use the [Nix development shell](./nix.md):
+it provides the compiler and every tool CI uses,
+without installing anything system-wide.
 
-```bash
-nix --experimental-features 'nix-command flakes' develop
-```
+### macOS: Apple Clang
 
-On **Linux**, Nix also provides the compiler (GCC); on **macOS**, it provides
-Clang. If you instead opt to use your system-wide Apple Clang (via
-`nix develop .#apple-clang`), you need to manage its version yourself (see
-below).
-
-See [Using the Nix development shell](./nix.md) for installation and usage
-details, including how to select a different compiler and why we recommend Nix
-over a hand-maintained environment.
-
-### macOS: managing the Apple Clang version
-
-If you use your system-wide Apple Clang on macOS (via `nix develop .#apple-clang`),
-the compiler version is whatever your installed Xcode (or Command Line Tools)
-provides. The following command should return a version greater than or equal to
-the [tested one](#tested-compiler-versions):
-
-```bash
-clang --version
-```
-
-If you develop other applications using Xcode, you might be consistently
-updating to the newest version of Apple Clang, which will likely cause issues
-building xrpld. You may want to install and pin a specific version of Xcode:
-
-1. **Download Xcode**
-   - Visit [Apple Developer Downloads](https://developer.apple.com/download/more/)
-   - Sign in with your Apple Developer account
-   - Search for an Xcode version that includes the expected Apple Clang version
-   - Download the `.xip` file
-
-2. **Install and configure Xcode**
-
-   ```bash
-   # Extract the .xip file and rename for version management
-   # Example: Xcode_16.2.app
-
-   # Move to Applications directory
-   sudo mv Xcode_16.2.app /Applications/
-
-   # Set as default toolchain (persistent)
-   sudo xcode-select -s /Applications/Xcode_16.2.app/Contents/Developer
-
-   # Set as environment variable (temporary)
-   export DEVELOPER_DIR=/Applications/Xcode_16.2.app/Contents/Developer
-   ```
+You can also build with the system Apple Clang,
+installing the other [required tools](#required-tools) any way you like
+(or getting them from `nix develop .#apple-clang`).
+Its version is whatever your installed Xcode (or Command Line Tools) provides,
+so check that `clang --version` is at least the [tested one](#tested-compiler-versions).
+If several Xcode versions are installed,
+select one with `sudo xcode-select -s <path>` or the `DEVELOPER_DIR` environment variable.
 
 ## Windows
 
@@ -123,8 +90,7 @@ manually:
   "x64 Native Tools Command Prompt". CI configures CMake with the
   `Visual Studio 18 2026` generator.
 - [Git for Windows](https://git-scm.com/download/win)
-- Python, Conan, and CMake, at the versions listed in
-  [Required tools](#required-tools).
+- recent releases of Python, Conan, and CMake
 - a [Rust toolchain](https://rustup.rs) — only needed to build with
   `-Drust=ON`, see [Rust](#rust)
 
@@ -145,16 +111,5 @@ version.
 Everything else the Rust build needs on the CMake side comes from Conan along
 with the rest of the dependencies, so there is nothing further to install.
 
-## Clang-tidy
-
-`clang-tidy` is required to run static analysis checks locally (see
-[CONTRIBUTING.md](../../CONTRIBUTING.md)). It is not required to build the
-project. The version this project uses is listed in
-[Tested compiler versions](#tested-compiler-versions).
-
-On Linux and macOS, the [Nix development shell](./nix.md) provides that exact
-version out of the box — run it via `run-clang-tidy`. No separate installation
-is needed.
-
 [cpp23-support]: https://en.cppreference.com/w/cpp/compiler_support/23
 [packages.nix]: ../../nix/packages.nix

docs/build/nix.md

@@ -9,9 +9,7 @@ This guide explains how to use Nix to set up a reproducible development environm
 - **Reproducible environment**: Everyone gets the same versions of tools and compilers
 - **Matches CI**: The Linux CI runs in Docker images built from this exact Nix environment, and CI builds some macOS configurations in it as well
 - **No system pollution**: Dependencies are isolated and don't affect your system packages
-- **Consistent compilers**: The GCC and Clang shells use the same versions as CI
 - **Quick setup**: Get started with a single command
-- **Works on Linux and macOS**: Consistent experience across platforms
 
 ## Install Nix
 
@@ -27,13 +25,8 @@ From the root of the xrpld repository, enter the default development shell:
 nix --experimental-features 'nix-command flakes' develop
 ```
 
-This will:
-
-- Download and set up all required development tools (CMake, Ninja, Conan, etc.)
-- Configure the appropriate compiler for your platform:
-  - **Linux**: GCC (provided by Nix)
-  - **macOS**: Clang (provided by Nix)
-
+This downloads and sets up all required development tools (CMake, Ninja, Conan, etc.)
+and the compiler for your platform (see [Platform notes](#platform-notes)).
 The first time you run this command, it will take a few minutes to download and build the environment. Subsequent runs will be much faster.
 
 ### Platform notes

docs/install.md

@@ -10,6 +10,19 @@ and DNF on Red Hat-based distributions such as RHEL, AlmaLinux, and Rocky Linux,
 where `yum` is a symlink to `dnf`.
 To build from source instead, see [BUILD.md](../BUILD.md).
 
+## Requirements
+
+Linux is the only operating system officially supported for running `xrpld`;
+macOS and Windows builds are for development only.
+
+Any x86-64 Linux distribution with APT or DNF and glibc 2.31 or newer should work
+(see [How libc is handled](../nix/docker/README.md#how-libc-is-handled)).
+CI tests the packages on Debian 11–13, Ubuntu 20.04–26.04,
+RHEL (UBI) 9–10, AlmaLinux 9–10, and Rocky Linux 9–10.
+
+For the hardware needed to run a node,
+see [System Requirements](https://xrpl.org/system-requirements.html).
+
 ## Release channels
 
 Packages are published to four channels:

include/xrpl/basics/MathUtilities.h

@@ -39,6 +39,31 @@ checkedSub(std::int64_t a, std::int64_t b) noexcept
     return a - b;
 }
 
+/**
+ * Multiply two signed 64-bit integers, returning std::nullopt when the exact
+ * mathematical product is not representable in std::int64_t.
+ */
+[[nodiscard]] constexpr std::optional<std::int64_t>
+checkedMul(std::int64_t a, std::int64_t b) noexcept
+{
+    using L = std::numeric_limits<std::int64_t>;
+
+    if (a == 0 || b == 0)
+        return 0;
+
+    if (a > 0)
+    {
+        if (b > 0 ? a > L::max() / b : b < L::min() / a)
+            return std::nullopt;
+    }
+    else if (b > 0 ? a < L::min() / b : b < L::max() / a)
+    {
+        return std::nullopt;
+    }
+
+    return a * b;
+}
+
 static_assert(checkedAdd(0, 0) == 0);
 static_assert(checkedAdd(1, -1) == 0);
 static_assert(checkedAdd(-5, 2) == -3);
@@ -81,6 +106,53 @@ static_assert(
     !checkedSub(std::numeric_limits<std::int64_t>::min(), std::numeric_limits<std::int64_t>::max())
          .has_value());
 
+static_assert(checkedMul(0, std::numeric_limits<std::int64_t>::min()) == 0);
+static_assert(checkedMul(std::numeric_limits<std::int64_t>::min(), 0) == 0);
+static_assert(checkedMul(-1, -1) == 1);
+// a > 0, b > 0
+static_assert(
+    checkedMul(std::numeric_limits<std::int64_t>::max(), 1) ==
+    std::numeric_limits<std::int64_t>::max());
+static_assert(
+    checkedMul(std::numeric_limits<std::int64_t>::max() / 2, 2) ==
+    std::numeric_limits<std::int64_t>::max() - 1);
+static_assert(!checkedMul((std::numeric_limits<std::int64_t>::max() / 2) + 1, 2).has_value());
+static_assert(!checkedMul(2, (std::numeric_limits<std::int64_t>::max() / 2) + 1).has_value());
+// a > 0, b < 0
+static_assert(
+    checkedMul(std::numeric_limits<std::int64_t>::max(), -1) ==
+    -std::numeric_limits<std::int64_t>::max());
+static_assert(
+    checkedMul((std::numeric_limits<std::int64_t>::max() / 2) + 1, -2) ==
+    std::numeric_limits<std::int64_t>::min());
+static_assert(!checkedMul((std::numeric_limits<std::int64_t>::max() / 2) + 2, -2).has_value());
+static_assert(
+    checkedMul(1, std::numeric_limits<std::int64_t>::min()) ==
+    std::numeric_limits<std::int64_t>::min());
+static_assert(
+    checkedMul(2, std::numeric_limits<std::int64_t>::min() / 2) ==
+    std::numeric_limits<std::int64_t>::min());
+static_assert(!checkedMul(2, (std::numeric_limits<std::int64_t>::min() / 2) - 1).has_value());
+// a < 0, b > 0
+static_assert(
+    checkedMul(std::numeric_limits<std::int64_t>::min(), 1) ==
+    std::numeric_limits<std::int64_t>::min());
+static_assert(
+    checkedMul(std::numeric_limits<std::int64_t>::min() / 2, 2) ==
+    std::numeric_limits<std::int64_t>::min());
+static_assert(!checkedMul((std::numeric_limits<std::int64_t>::min() / 2) - 1, 2).has_value());
+static_assert(!checkedMul(std::numeric_limits<std::int64_t>::min(), 2).has_value());
+// a < 0, b < 0
+static_assert(
+    checkedMul(-(std::numeric_limits<std::int64_t>::max() / 2), -2) ==
+    std::numeric_limits<std::int64_t>::max() - 1);
+static_assert(!checkedMul(std::numeric_limits<std::int64_t>::min() / 2, -2).has_value());
+static_assert(
+    checkedMul(-1, -std::numeric_limits<std::int64_t>::max()) ==
+    std::numeric_limits<std::int64_t>::max());
+static_assert(!checkedMul(std::numeric_limits<std::int64_t>::min(), -1).has_value());
+static_assert(!checkedMul(-1, std::numeric_limits<std::int64_t>::min()).has_value());
+
 /**
  * Calculate one number divided by another number in percentage.
  * The result is rounded up to the next integer, and capped in the range [0,100]

include/xrpl/basics/Number.h

@@ -352,9 +352,9 @@ class Number final
     using rep = std::int64_t;
     using InternalRep = MantissaRange::rep;
 
-    bool negative_{false};
     InternalRep mantissa_{0};
     int exponent_{std::numeric_limits<int>::lowest()};
+    bool negative_{false};
 
 public:
     // The range for the exponent when normalized
@@ -650,8 +650,12 @@ private:
     shiftExponent(int exponentDelta) const;
 };
 
+// The number class currently has 3 tail padding bytes. If you are adding new
+// members, try to fit them there before expanding the size of the class.
+static_assert(sizeof(Number) == 16);
+
 constexpr Number::Number(bool negative, InternalRep mantissa, int exponent, Unchecked) noexcept
-    : negative_(negative), mantissa_{mantissa}, exponent_{exponent}
+    : mantissa_{mantissa}, exponent_{exponent}, negative_(negative)
 {
 }
 

include/xrpl/basics/TaggedCache.h

@@ -153,6 +153,24 @@ private:
         Policy policy,
         Callback&& replaceCallback = nullptr);
 
+    /**
+     * canonicalizeImpl variant for callers that already hold `mutex_`.
+     *
+     * The unnamed `scoped_lock<MutexType> const&` parameter is proof of
+     * ownership; this overload does not acquire the lock. Use it from other
+     * methods (e.g. fetchAndModify) that need to compose canonicalize with
+     * additional work under a single critical section, without relying on
+     * recursive-mutex re-entry.
+     */
+    template <class Policy, class Callback = std::nullptr_t>
+    bool
+    canonicalizeImpl(
+        std::scoped_lock<MutexType> const&,
+        key_type const& key,
+        CanonicalizeClientPointerType<Policy> data,
+        Policy policy,
+        Callback&& replaceCallback = nullptr);
+
 public:
     /**
      * Replace aliased objects with originals.
@@ -239,9 +257,6 @@ public:
     bool
     retrieve(key_type const& key, T& data);
 
-    MutexType&
-    peekMutex();
-
     std::vector<key_type>
     getKeys() const;
 
@@ -263,6 +278,22 @@ public:
     fetch(key_type const& digest, Handler const& h);
     // End CachedSLEs functions.
 
+    /**
+     * Fetch or create an entry and execute a callback while holding the lock.
+     *
+     * The entry for the given key is fetched from the cache or created if it
+     * doesn't exist. The callback is then invoked with a reference to the
+     * entry while the cache mutex is still held, allowing safe modification
+     * of the cached object.
+     *
+     * @param key The key to fetch or create
+     * @param callback Function to call with the entry under lock.
+     *                 Signature: void(T&)
+     */
+    template <class Callback>
+    void
+    fetchAndModify(key_type const& key, Callback&& callback);
+
 private:
     SharedPointerType
     initialFetch(key_type const& key, std::scoped_lock<MutexType> const& l);

include/xrpl/basics/TaggedCache.ipp

@@ -4,6 +4,7 @@
 #include <xrpl/basics/Log.h>  // IWYU pragma: keep
 #include <xrpl/basics/TaggedCache.h>
 #include <xrpl/basics/scope.h>
+#include <xrpl/beast/utility/instrumentation.h>
 
 #include <algorithm>
 
@@ -335,6 +336,29 @@ template <class Policy, class Callback>
 inline bool
 TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash, KeyEqual, Mutex>::
     canonicalizeImpl(
+        key_type const& key,
+        CanonicalizeClientPointerType<Policy> data,
+        Policy policy,
+        Callback&& replaceCallback)
+{
+    std::scoped_lock<MutexType> const lock(mutex_);
+    return canonicalizeImpl(lock, key, data, policy, std::forward<Callback>(replaceCallback));
+}
+
+template <
+    class Key,
+    class T,
+    bool IsKeyCache,
+    class SharedWeakUnionPointer,
+    class SharedPointerType,
+    class Hash,
+    class KeyEqual,
+    class Mutex>
+template <class Policy, class Callback>
+inline bool
+TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash, KeyEqual, Mutex>::
+    canonicalizeImpl(
+        std::scoped_lock<MutexType> const&,
         key_type const& key,
         CanonicalizeClientPointerType<Policy> data,
         [[maybe_unused]] Policy policy,
@@ -354,8 +378,6 @@ TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash,
     // passing a const argument is a compile error.
     constexpr bool replaceCached = std::is_same_v<Policy, detail::ReplaceCached>;
 
-    std::scoped_lock const lock(mutex_);
-
     auto const cit = cache_.find(key);
 
     if (cit == cache_.end())
@@ -572,22 +594,6 @@ TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash,
     return true;
 }
 
-template <
-    class Key,
-    class T,
-    bool IsKeyCache,
-    class SharedWeakUnionPointer,
-    class SharedPointerType,
-    class Hash,
-    class KeyEqual,
-    class Mutex>
-inline auto
-TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash, KeyEqual, Mutex>::
-    peekMutex() -> MutexType&
-{
-    return mutex_;
-}
-
 template <
     class Key,
     class T,
@@ -700,6 +706,49 @@ TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash,
 }
 // End CachedSLEs functions.
 
+template <
+    class Key,
+    class T,
+    bool IsKeyCache,
+    class SharedWeakUnionPointer,
+    class SharedPointerType,
+    class Hash,
+    class KeyEqual,
+    class Mutex>
+template <class Callback>
+inline void
+TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash, KeyEqual, Mutex>::
+    fetchAndModify(key_type const& key, Callback&& callback)
+{
+    static_assert(
+        !IsKeyCache, "fetchAndModify is only supported for value caches, not key-only caches");
+    static_assert(
+        std::is_same_v<std::shared_ptr<T>, SharedPointerType> ||
+            std::is_same_v<intr_ptr::SharedPtr<T>, SharedPointerType>,
+        "fetchAndModify requires std::shared_ptr<T> or intr_ptr::SharedPtr<T>");
+
+    std::scoped_lock<MutexType> const lock(mutex_);
+
+    // Same pointer-type dispatch as insert(): the placeholder must have exactly
+    // SharedPointerType so canonicalizeImpl can write the cached pointer back.
+    SharedPointerType entry = [] {
+        if constexpr (std::is_same_v<std::shared_ptr<T>, SharedPointerType>)
+        {
+            return std::make_shared<T>();
+        }
+        else
+        {
+            return intr_ptr::makeShared<T>();
+        }
+    }();
+    canonicalizeImpl(lock, key, entry, detail::ReplaceClient{});
+
+    ALWAYS(
+        entry != nullptr, "xrpl::TaggedCache::fetchAndModify : entry present after canonicalize");
+
+    callback(*entry);
+}
+
 template <
     class Key,
     class T,

include/xrpl/basics/enum_bitops.h

@@ -0,0 +1,200 @@
+#pragma once
+
+#include <concepts>
+#include <type_traits>
+#include <utility>
+
+namespace xrpl {
+
+/**
+ * Opt-in bitwise operators for scoped enumerations.
+ *
+ * Provides `&`, `|`, `^`, `~` and the corresponding compound assignment forms
+ * for any scoped enumeration with an unsigned underlying type that opts in by
+ * specializing @ref OptIn:
+ *
+ * @code
+ * namespace xrpl {
+ *
+ * enum class MyFlags : std::uint32_t { a = 1, b = 2, c = 4 };
+ *
+ * template <>
+ * struct enum_bitops::OptIn<MyFlags> : std::true_type {};
+ *
+ * }  // namespace xrpl
+ * @endcode
+ *
+ * The operators are constexpr and noexcept, and return the enumeration type.
+ *
+ * @par Where the specialization may be declared
+ *   In namespace xrpl, or at global scope with full qualification, and after
+ *   the enumeration is defined but before the operators are first used. This
+ *   cannot be done in a nested namespace or at class scope; for enumerations
+ *   nested in a class this means after the class definition.
+ *
+ * @par Where the operators are found
+ *   The operators are declared in namespace xrpl, so argument-dependent lookup
+ *   will find them only for enumerations declared in xrpl or nested in a class
+ *   declared directly in xrpl. Enumerations in a nested namespace will only be
+ *   found from code inside xrpl, and only if no enclosing scope declares an
+ *   operator of the same name; elsewhere they require using-declarations.
+ */
+namespace enum_bitops {
+
+/**
+ * Types that may be opted in to the bitwise operators.
+ *
+ * Satisfied by a scoped enumeration whose underlying type is an unsigned
+ * integer type.
+ *
+ * @tparam T The type to test.
+ */
+template <typename T>
+concept Eligible = std::is_scoped_enum_v<T> && std::unsigned_integral<std::underlying_type_t<T>>;
+
+/**
+ * Opt-in switch for the bitwise operators.
+ *
+ * The primary template derives from std::false_type. Specialize it to derive
+ * from std::true_type to enable the operators for an @ref Eligible enumeration.
+ *
+ * @tparam T The scoped enumeration to opt in.
+ */
+template <Eligible T>
+struct OptIn : std::false_type
+{
+};
+
+/**
+ * Enumerations for which the bitwise operators are enabled.
+ *
+ * Satisfied when @p T satisfies @ref Eligible and @ref OptIn has been
+ * specialized for it to derive from std::true_type.
+ *
+ * @tparam T The type to test.
+ */
+template <typename T>
+concept Candidate = Eligible<T> && OptIn<T>::value;
+
+}  // namespace enum_bitops
+
+// These are declared in xrpl, not in enum_bitops, so that argument-dependent
+// lookup finds them for enumerations whose associated namespace is xrpl.
+
+/**
+ * @name Bitwise operators for opted-in scoped enumerations
+ *
+ * Each operator applies the corresponding built-in operator to the
+ * underlying values and converts the result back to the enumeration type.
+ * Both operands must have the same enumeration type; there is no implicit
+ * conversion to or from the underlying type.
+ */
+/** @{ */
+
+/**
+ * Bitwise AND.
+ *
+ * @param lhs The left operand.
+ * @param rhs The right operand.
+ * @return The bits set in both @p lhs and @p rhs.
+ */
+template <enum_bitops::Candidate T>
+constexpr T
+operator&(T lhs, T rhs) noexcept
+{
+    return static_cast<T>(std::to_underlying(lhs) & std::to_underlying(rhs));
+}
+
+/**
+ * Bitwise OR.
+ *
+ * @param lhs The left operand.
+ * @param rhs The right operand.
+ * @return The bits set in @p lhs, in @p rhs, or in both.
+ */
+template <enum_bitops::Candidate T>
+constexpr T
+operator|(T lhs, T rhs) noexcept
+{
+    return static_cast<T>(std::to_underlying(lhs) | std::to_underlying(rhs));
+}
+
+/**
+ * Bitwise exclusive OR.
+ *
+ * @param lhs The left operand.
+ * @param rhs The right operand.
+ * @return The bits set in exactly one of @p lhs and @p rhs.
+ */
+template <enum_bitops::Candidate T>
+constexpr T
+operator^(T lhs, T rhs) noexcept
+{
+    return static_cast<T>(std::to_underlying(lhs) ^ std::to_underlying(rhs));
+}
+
+/**
+ * Bitwise complement.
+ *
+ * The result has every bit of the underlying type that is clear in
+ * @p val, including bits that no enumerator names. It is intended for
+ * clearing flags, as in `flags & ~flag`.
+ *
+ * @param val The operand.
+ * @return The complement of @p val.
+ */
+template <enum_bitops::Candidate T>
+constexpr T
+operator~(T val) noexcept
+{
+    return static_cast<T>(~std::to_underlying(val));
+}
+
+/**
+ * Bitwise AND assignment.
+ *
+ * @param lhs The value to modify.
+ * @param rhs The right operand.
+ * @return A reference to @p lhs.
+ */
+template <enum_bitops::Candidate T>
+constexpr T&
+operator&=(T& lhs, T rhs) noexcept
+{
+    lhs = lhs & rhs;
+    return lhs;
+}
+
+/**
+ * Bitwise OR assignment.
+ *
+ * @param lhs The value to modify.
+ * @param rhs The right operand.
+ * @return A reference to @p lhs.
+ */
+template <enum_bitops::Candidate T>
+constexpr T&
+operator|=(T& lhs, T rhs) noexcept
+{
+    lhs = lhs | rhs;
+    return lhs;
+}
+
+/**
+ * Bitwise exclusive OR assignment.
+ *
+ * @param lhs The value to modify.
+ * @param rhs The right operand.
+ * @return A reference to @p lhs.
+ */
+template <enum_bitops::Candidate T>
+constexpr T&
+operator^=(T& lhs, T rhs) noexcept
+{
+    lhs = lhs ^ rhs;
+    return lhs;
+}
+
+/** @} */
+
+}  // namespace xrpl

include/xrpl/config/Constants.h

@@ -94,6 +94,7 @@ struct Keys
     static constexpr auto kBbtOptions = "bbt_options";
     static constexpr auto kBgThreads = "bg_threads";
     static constexpr auto kBlockSize = "block_size";
+    static constexpr auto kBytecodeSizeLimit = "bytecode_size_limit";
     static constexpr auto kCacheAge = "cache_age";
     static constexpr auto kCacheMb = "cache_mb";
     static constexpr auto kCacheSize = "cache_size";
@@ -108,6 +109,8 @@ struct Keys
     static constexpr auto kFileSizeMult = "file_size_mult";
     static constexpr auto kFilterBits = "filter_bits";
     static constexpr auto kFilterFull = "filter_full";
+    static constexpr auto kGasLimit = "gas_limit";
+    static constexpr auto kGasPrice = "gas_price";
     static constexpr auto kHardSet = "hard_set";
     static constexpr auto kHighThreads = "high_threads";
     static constexpr auto kHoldTime = "hold_time";

include/xrpl/json/json_value.h

@@ -3,13 +3,11 @@
 #include <xrpl/basics/Number.h>
 #include <xrpl/json/json_forwards.h>
 
-#include <concepts>
 #include <cstring>
 #include <iterator>
 #include <limits>
 #include <map>
 #include <string>
-#include <string_view>
 #include <vector>
 
 /**
@@ -200,15 +198,6 @@ public:
      */
     Value(StaticString const& value);
     Value(std::string const& value);
-    /**
-     * @brief Constructs a value from a string view.
-     *
-     * The characters are copied, so the view need not outlive the call and need
-     * not be NUL-terminated.
-     *
-     * @param value The characters to copy.
-     */
-    Value(std::string_view value);
     Value(bool value);
     Value(Value const& other);
     ~Value();
@@ -483,32 +472,6 @@ toJson(xrpl::Number const& number)
 bool
 operator==(Value const&, Value const&);
 
-/**
- * Compares a value with a string view, reading the value's characters in place
- * rather than building a Value from the view.
- *
- * Constrained to the exact type: a string literal converts equally well to a
- * view and to a Value, so a plain overload makes `value == "literal"`
- * ambiguous.
- *
- * @param x The value to compare.
- * @param y The characters to compare it against.
- * @return Whether `x` is a string whose characters up to its first NUL are
- *         exactly the characters of `y`.
- */
-template <class T>
-    requires std::same_as<T, std::string_view>
-bool
-operator==(Value const& x, T y)
-{
-    if (!x.isString())
-        return false;
-
-    // A string `Value` can hold a null pointer, which names no characters, so it equals no view.
-    char const* const s = x.asCString();
-    return s != nullptr && std::string_view{s} == y;
-}
-
 bool
 operator<(Value const&, Value const&);
 

include/xrpl/ledger/ApplyView.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <xrpl/basics/base_uint.h>
-#include <xrpl/basics/safe_cast.h>
+#include <xrpl/basics/enum_bitops.h>
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/ledger/OwnerCounts.h>
 #include <xrpl/ledger/ReadView.h>
@@ -22,80 +22,39 @@
 
 namespace xrpl {
 
-// Bitwise flag enum with existing operator overloads
-// NOLINTNEXTLINE(cppcoreguidelines-use-enum-class)
-enum ApplyFlags : std::uint32_t {
-    TapNone = 0x00,
+enum class ApplyFlags : std::uint32_t {
+    None = 0x00,
 
     // This is a local transaction with the
     // fail_hard flag set.
-    TapFailHard = 0x10,
+    FailHard = 0x10,
 
     // This is not the transaction's last pass
     // Transaction can be retried, soft failures allowed
-    TapRetry = 0x20,
+    Retry = 0x20,
 
     // Transaction came from a privileged source
-    TapUnlimited = 0x400,
+    Unlimited = 0x400,
 
     // Transaction is executing as part of a batch
-    TapBatch = 0x800,
+    Batch = 0x800,
 
     // Transaction shouldn't be applied
     // Signatures shouldn't be checked
-    TapDryRun = 0x1000,
+    DryRun = 0x1000,
 
     // Transaction is being preflighted as the payload of a
     // TransactionProposalCreate. Its signatures are collected on-ledger
     // afterward, so signature-presence checks (e.g. Batch signer matching)
     // are skipped at proposal-creation time (On-Chain Cosigner spec
     // §5.3.1.2).
-    TapProposal = 0x2000,
+    Proposal = 0x2000,
 };
 
-constexpr ApplyFlags
-operator|(ApplyFlags const& lhs, ApplyFlags const& rhs)
+template <>
+struct enum_bitops::OptIn<ApplyFlags> : std::true_type
 {
-    return safeCast<ApplyFlags>(
-        safeCast<std::underlying_type_t<ApplyFlags>>(lhs) |
-        safeCast<std::underlying_type_t<ApplyFlags>>(rhs));
-}
-
-static_assert((TapFailHard | TapRetry) == safeCast<ApplyFlags>(0x30u), "ApplyFlags operator |");
-static_assert((TapRetry | TapFailHard) == safeCast<ApplyFlags>(0x30u), "ApplyFlags operator |");
-
-constexpr ApplyFlags
-operator&(ApplyFlags const& lhs, ApplyFlags const& rhs)
-{
-    return safeCast<ApplyFlags>(
-        safeCast<std::underlying_type_t<ApplyFlags>>(lhs) &
-        safeCast<std::underlying_type_t<ApplyFlags>>(rhs));
-}
-
-static_assert((TapFailHard & TapRetry) == TapNone, "ApplyFlags operator &");
-static_assert((TapRetry & TapFailHard) == TapNone, "ApplyFlags operator &");
-
-constexpr ApplyFlags
-operator~(ApplyFlags const& flags)
-{
-    return safeCast<ApplyFlags>(~safeCast<std::underlying_type_t<ApplyFlags>>(flags));
-}
-
-static_assert(~TapRetry == safeCast<ApplyFlags>(0xFFFFFFDFu), "ApplyFlags operator ~");
-
-inline ApplyFlags
-operator|=(ApplyFlags& lhs, ApplyFlags const& rhs)
-{
-    lhs = lhs | rhs;
-    return lhs;
-}
-
-inline ApplyFlags
-operator&=(ApplyFlags& lhs, ApplyFlags const& rhs)
-{
-    lhs = lhs & rhs;
-    return lhs;
-}
+};
 
 //------------------------------------------------------------------------------
 

include/xrpl/ledger/Ledger.h

@@ -257,13 +257,42 @@ public:
         header_.validated = true;
     }
 
-    void
+    /**
+     * Mark this ledger as accepted and attempt to make it immutable.
+     *
+     * The close-time fields are recorded first, since the ledger hash covers
+     * them.
+     *
+     * @param closeTime The consensus-agreed close time.
+     * @param closeResolution The close time resolution.
+     * @param correctCloseTime Whether consensus agreed on the close time. If
+     *        false, kSLcfNoConsensusTime is recorded in closeFlags instead.
+     * @return What setImmutable() returned.
+     */
+    [[nodiscard]] bool
     setAccepted(
         NetClock::time_point closeTime,
         NetClock::duration closeResolution,
         bool correctCloseTime);
 
-    void
+    /**
+     * Mark this ledger as immutable, so it can no longer be modified.
+     *
+     * A ledger built or loaded locally cannot have an invalid map, since only
+     * a map syncing against hashes from outside can be proven impossible (see
+     * SHAMap::addKnownNode), so a caller on such a path may treat a false
+     * return as a broken internal invariant. A caller assembling a ledger from
+     * peer data may not: for it, false is an outcome a peer can produce.
+     *
+     * @param rehash Whether to recompute the ledger hash from the header
+     *        fields. The transaction and account hashes are recomputed from the
+     *        maps too, but only the first time.
+     * @return false if either map is Invalid, leaving the immutable flag as it
+     *         was and the header untouched. A map invalidated partway through can
+     *         still leave the other one immutable, so a false return means the
+     *         ledger must be discarded rather than retried.
+     */
+    [[nodiscard]] bool
     setImmutable(bool rehash = true);
 
     bool
@@ -272,23 +301,28 @@ public:
         return immutable_;
     }
 
-    /*  Mark this ledger as "should be full".
+    /**
+     * @return Whether both maps can still be the maps the header names. See
+     *         SHAMap::isValid().
+     */
+    [[nodiscard]] bool
+    mapsValid() const
+    {
+        return txMap_.isValid() && stateMap_.isValid();
+    }
 
-        "Full" is metadata property of the ledger, it indicates
-        that the local server wants all the corresponding nodes
-        in durable storage.
-
-        This is marked `const` because it reflects metadata
-        and not data that is in common with other nodes on the
-        network.
-    */
+    /**
+     * Mark this ledger as "should be full", indicating that the local server
+     * wants all the corresponding nodes in durable storage.
+     *
+     * Const because it reflects metadata, not data this ledger shares with
+     * other nodes on the network.
+     */
     void
     setFull() const
     {
-        txMap_.setFull();
-        txMap_.setLedgerSeq(header_.seq);
-        stateMap_.setFull();
-        stateMap_.setLedgerSeq(header_.seq);
+        txMap_.setFull(header_.seq);
+        stateMap_.setFull(header_.seq);
     }
 
     void
@@ -418,6 +452,22 @@ private:
     static std::pair<std::shared_ptr<STTx const>, std::shared_ptr<STObject const>>
     deserializeTxPlusMeta(SHAMapItem const& item);
 
+    /**
+     * Make both maps immutable.
+     *
+     * Each map is settled on its own, so neither is left mid-sync because the
+     * other refused.
+     *
+     * @return Whether both maps are immutable.
+     */
+    [[nodiscard]] bool
+    setMapsImmutable()
+    {
+        bool const txImmutable = txMap_.setImmutable();
+        bool const stateImmutable = stateMap_.setImmutable();
+        return txImmutable && stateImmutable;
+    }
+
     bool immutable_;
 
     // A SHAMap containing the transactions associated with this ledger.

include/xrpl/ledger/View.h

@@ -265,6 +265,13 @@ canWithdraw(
 [[nodiscard]] TER
 canWithdraw(ReadView const& view, STTx const& tx);
 
+/**
+ * Pays out a withdrawal from a vault or loan broker pseudo-account.
+ *
+ * `sourceAmount` leaves `sourceAcct` and `destinationAmount` reaches `dstAcct`.
+ * The two differ only when the withdrawal carries a transfer fee; the
+ * difference is the fee and is settled through the issuer.
+ */
 [[nodiscard]] TER
 doWithdraw(
     ApplyViewContext ctx,
@@ -272,7 +279,8 @@ doWithdraw(
     AccountID const& dstAcct,
     AccountID const& sourceAcct,
     XRPAmount priorBalance,
-    STAmount const& amount,
+    STAmount const& destinationAmount,
+    STAmount const& sourceAmount,
     beast::Journal j);
 
 /**

include/xrpl/ledger/helpers/AMMHelpers.h

@@ -2,7 +2,6 @@
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/Number.h>
-#include <xrpl/basics/contract.h>
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/beast/utility/Zero.h>
 #include <xrpl/ledger/ApplyView.h>
@@ -29,7 +28,6 @@
 #include <expected>
 #include <functional>
 #include <optional>
-#include <stdexcept>
 #include <tuple>
 #include <utility>
 
@@ -313,11 +311,11 @@ getAMMOfferStartWithTakerPays(
  * is equal to LOB quality (in this case AMM offer quality is
  * better than LOB quality) or AMM offer is equal to LOB quality
  * (in this case SPQ is better than LOB quality).
- * Pre-amendment code calculates takerPays first. If takerGets is the
- * economically coarser integral side, it is rounded down, which results in
- * worse offer quality than LOB quality, and the offer might fail to generate.
- * Post-amendment code calculates the economically coarser integral offer side
- * first. The result is rounded down, which makes the offer quality better.
+ * The economically coarser integral offer side is calculated first. The
+ * result is rounded down, which makes the offer quality better. Calculating
+ * takerPays first instead would round down takerGets when that is the coarser
+ * side, giving worse quality than LOB quality, and the offer might fail to
+ * generate.
  *   It might not be possible to match either SPQ or AMM offer to LOB
  * quality. This generally happens at higher fees.
  * @param pool AMM pool balances
@@ -331,69 +329,8 @@ changeSpotPriceQuality(
     TAmounts<TIn, TOut> const& pool,
     Quality const& quality,
     std::uint16_t tfee,
-    Rules const& rules,
     beast::Journal j)
 {
-    if (!rules.enabled(fixAMMv1_1))
-    {
-        // Finds takerPays (i) and takerGets (o) such that given pool
-        // composition poolGets(I) and poolPays(O): (O - o) / (I + i) = quality.
-        // Where takerGets is calculated as the swapAssetIn (see below).
-        // The above equation produces the quadratic equation:
-        // i^2*(1-fee) + i*I*(2-fee) + I^2 - I*O/quality,
-        // which is solved for i, and o is found with swapAssetIn().
-        auto const f = feeMult(tfee);  // 1 - fee
-        auto const& a = f;
-        auto const b = pool.in * (1 + f);
-        Number const c = pool.in * pool.in - pool.in * pool.out * quality.rate();
-        auto const res = b * b - 4 * a * c;
-        if (res < 0)
-        {
-            return std::nullopt;  // LCOV_EXCL_LINE
-        }
-        if (auto const nTakerPaysPropose = (-b + root2(res)) / (2 * a); nTakerPaysPropose > 0)
-        {
-            auto const nTakerPays = [&] {
-                // The fee might make the AMM offer quality less than CLOB
-                // quality. Therefore, AMM offer has to satisfy this constraint:
-                // o / i >= q. Substituting o with swapAssetIn() gives: i <= O /
-                // q - I / (1 - fee).
-                auto const nTakerPaysConstraint = pool.out * quality.rate() - pool.in / f;
-                if (nTakerPaysPropose > nTakerPaysConstraint)
-                    return nTakerPaysConstraint;
-                return nTakerPaysPropose;
-            }();
-            if (nTakerPays <= 0)
-            {
-                JLOG(j.trace()) << "changeSpotPriceQuality calc failed: " << to_string(pool.in)
-                                << " " << to_string(pool.out) << " " << quality << " " << tfee;
-                return std::nullopt;
-            }
-            auto const takerPays =
-                toAmount<TIn>(getAsset(pool.in), nTakerPays, Number::RoundingMode::Upward);
-            // should not fail
-            auto amounts = TAmounts<TIn, TOut>{takerPays, swapAssetIn(pool, takerPays, tfee)};
-            if (Quality{amounts} < quality &&
-                !withinRelativeDistance(Quality{amounts}, quality, Number(1, -7)))
-            {
-                JLOG(j.error()) << "changeSpotPriceQuality failed: " << to_string(pool.in) << " "
-                                << to_string(pool.out) << " "
-                                << " " << quality << " " << tfee << " " << to_string(amounts.in)
-                                << " " << to_string(amounts.out);
-                Throw<std::runtime_error>("changeSpotPriceQuality failed");
-            }
-
-            JLOG(j.trace()) << "changeSpotPriceQuality succeeded: " << to_string(pool.in) << " "
-                            << to_string(pool.out) << " "
-                            << " " << quality << " " << tfee << " " << to_string(amounts.in) << " "
-                            << to_string(amounts.out);
-            return amounts;
-        }
-        JLOG(j.trace()) << "changeSpotPriceQuality calc failed: " << to_string(pool.in) << " "
-                        << to_string(pool.out) << " " << quality << " " << tfee;
-        return std::nullopt;
-    }
-
     auto amounts = [&] {
         bool const inIntegral = getAsset(pool.in).integral();
         bool const outIntegral = getAsset(pool.out).integral();
@@ -459,57 +396,49 @@ template <typename TIn, typename TOut>
 TOut
 swapAssetIn(TAmounts<TIn, TOut> const& pool, TIn const& assetIn, std::uint16_t tfee)
 {
-    if (auto const& rules = getCurrentTransactionRules(); rules && rules->enabled(fixAMMv1_1))
-    {
-        // set rounding to always favor the amm. Clip to zero.
-        // calculate:
-        // pool.out -
-        // (pool.in * pool.out) / (pool.in + assetIn * feeMult(tfee)),
-        // and explicitly set the rounding modes
-        // Favoring the amm means we should:
-        // minimize:
-        // pool.out -
-        // (pool.in * pool.out) / (pool.in + assetIn * feeMult(tfee)),
-        // maximize:
-        // (pool.in * pool.out) / (pool.in + assetIn * feeMult(tfee)),
-        // (pool.in * pool.out)
-        // minimize:
-        // (pool.in + assetIn * feeMult(tfee)),
-        // minimize:
-        // assetIn * feeMult(tfee)
-        // feeMult is: (1-fee), fee is tfee/100000
-        // minimize:
-        // 1-fee
-        // maximize:
-        // fee
-        SaveNumberRoundMode const _{Number::getround()};
+    // set rounding to always favor the amm. Clip to zero.
+    // calculate:
+    // pool.out -
+    // (pool.in * pool.out) / (pool.in + assetIn * feeMult(tfee)),
+    // and explicitly set the rounding modes
+    // Favoring the amm means we should:
+    // minimize:
+    // pool.out -
+    // (pool.in * pool.out) / (pool.in + assetIn * feeMult(tfee)),
+    // maximize:
+    // (pool.in * pool.out) / (pool.in + assetIn * feeMult(tfee)),
+    // (pool.in * pool.out)
+    // minimize:
+    // (pool.in + assetIn * feeMult(tfee)),
+    // minimize:
+    // assetIn * feeMult(tfee)
+    // feeMult is: (1-fee), fee is tfee/100000
+    // minimize:
+    // 1-fee
+    // maximize:
+    // fee
+    SaveNumberRoundMode const _{Number::getround()};
 
-        Number::setround(Number::RoundingMode::Upward);
-        auto const numerator = pool.in * pool.out;
-        auto const fee = getFee(tfee);
+    Number::setround(Number::RoundingMode::Upward);
+    auto const numerator = pool.in * pool.out;
+    auto const fee = getFee(tfee);
 
-        Number::setround(Number::RoundingMode::Downward);
-        auto const denom = pool.in + assetIn * (1 - fee);
+    Number::setround(Number::RoundingMode::Downward);
+    auto const denom = pool.in + assetIn * (1 - fee);
 
-        if (denom.signum() <= 0)
-            return toAmount<TOut>(getAsset(pool.out), 0);
+    if (denom.signum() <= 0)
+        return toAmount<TOut>(getAsset(pool.out), 0);
 
-        Number::setround(Number::RoundingMode::Upward);
-        auto const ratio = numerator / denom;
+    Number::setround(Number::RoundingMode::Upward);
+    auto const ratio = numerator / denom;
 
-        Number::setround(Number::RoundingMode::Downward);
-        auto const swapOut = pool.out - ratio;
+    Number::setround(Number::RoundingMode::Downward);
+    auto const swapOut = pool.out - ratio;
 
-        if (swapOut.signum() < 0)
-            return toAmount<TOut>(getAsset(pool.out), 0);
+    if (swapOut.signum() < 0)
+        return toAmount<TOut>(getAsset(pool.out), 0);
 
-        return toAmount<TOut>(getAsset(pool.out), swapOut, Number::RoundingMode::Downward);
-    }
-
-    return toAmount<TOut>(
-        getAsset(pool.out),
-        pool.out - (pool.in * pool.out) / (pool.in + assetIn * feeMult(tfee)),
-        Number::RoundingMode::Downward);
+    return toAmount<TOut>(getAsset(pool.out), swapOut, Number::RoundingMode::Downward);
 }
 
 /**
@@ -526,57 +455,49 @@ template <typename TIn, typename TOut>
 TIn
 swapAssetOut(TAmounts<TIn, TOut> const& pool, TOut const& assetOut, std::uint16_t tfee)
 {
-    if (auto const& rules = getCurrentTransactionRules(); rules && rules->enabled(fixAMMv1_1))
+    // set rounding to always favor the amm. Clip to zero.
+    // calculate:
+    // ((pool.in * pool.out) / (pool.out - assetOut) - pool.in) /
+    // (1-tfee/100000)
+    // maximize:
+    // ((pool.in * pool.out) / (pool.out - assetOut) - pool.in)
+    // maximize:
+    // (pool.in * pool.out) / (pool.out - assetOut)
+    // maximize:
+    // (pool.in * pool.out)
+    // minimize
+    // (pool.out - assetOut)
+    // minimize:
+    // (1-tfee/100000)
+    // maximize:
+    // tfee/100000
+
+    SaveNumberRoundMode const _{Number::getround()};
+
+    Number::setround(Number::RoundingMode::Upward);
+    auto const numerator = pool.in * pool.out;
+
+    Number::setround(Number::RoundingMode::Downward);
+    auto const denom = pool.out - assetOut;
+    if (denom.signum() <= 0)
     {
-        // set rounding to always favor the amm. Clip to zero.
-        // calculate:
-        // ((pool.in * pool.out) / (pool.out - assetOut) - pool.in) /
-        // (1-tfee/100000)
-        // maximize:
-        // ((pool.in * pool.out) / (pool.out - assetOut) - pool.in)
-        // maximize:
-        // (pool.in * pool.out) / (pool.out - assetOut)
-        // maximize:
-        // (pool.in * pool.out)
-        // minimize
-        // (pool.out - assetOut)
-        // minimize:
-        // (1-tfee/100000)
-        // maximize:
-        // tfee/100000
-
-        SaveNumberRoundMode const _{Number::getround()};
-
-        Number::setround(Number::RoundingMode::Upward);
-        auto const numerator = pool.in * pool.out;
-
-        Number::setround(Number::RoundingMode::Downward);
-        auto const denom = pool.out - assetOut;
-        if (denom.signum() <= 0)
-        {
-            return toMaxAmount<TIn>(getAsset(pool.in));
-        }
-
-        Number::setround(Number::RoundingMode::Upward);
-        auto const ratio = numerator / denom;
-        auto const numerator2 = ratio - pool.in;
-        auto const fee = getFee(tfee);
-
-        Number::setround(Number::RoundingMode::Downward);
-        auto const feeMult = 1 - fee;
-
-        Number::setround(Number::RoundingMode::Upward);
-        auto const swapIn = numerator2 / feeMult;
-        if (swapIn.signum() < 0)
-            return toAmount<TIn>(getAsset(pool.in), 0);
-
-        return toAmount<TIn>(getAsset(pool.in), swapIn, Number::RoundingMode::Upward);
+        return toMaxAmount<TIn>(getAsset(pool.in));
     }
 
-    return toAmount<TIn>(
-        getAsset(pool.in),
-        ((pool.in * pool.out) / (pool.out - assetOut) - pool.in) / feeMult(tfee),
-        Number::RoundingMode::Upward);
+    Number::setround(Number::RoundingMode::Upward);
+    auto const ratio = numerator / denom;
+    auto const numerator2 = ratio - pool.in;
+    auto const fee = getFee(tfee);
+
+    Number::setround(Number::RoundingMode::Downward);
+    auto const feeMult = 1 - fee;
+
+    Number::setround(Number::RoundingMode::Upward);
+    auto const swapIn = numerator2 / feeMult;
+    if (swapIn.signum() < 0)
+        return toAmount<TIn>(getAsset(pool.in), 0);
+
+    return toAmount<TIn>(getAsset(pool.in), swapIn, Number::RoundingMode::Upward);
 }
 
 /**

include/xrpl/ledger/helpers/EscrowHelpers.h

@@ -14,6 +14,7 @@
 #include <xrpl/protocol/AccountID.h>
 #include <xrpl/protocol/Concepts.h>
 #include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/Fees.h>
 #include <xrpl/protocol/Indexes.h>
 #include <xrpl/protocol/Issue.h>
 #include <xrpl/protocol/Keylet.h>
@@ -27,6 +28,8 @@
 #include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/UintTypes.h>
 
+#include <cstdint>
+
 namespace xrpl {
 
 /**
@@ -560,4 +563,54 @@ escrowUnlockApplyHelper<MPTIssue>(
         journal);
 }
 
+/**
+ * Smart escrow kill switches, driven by the voted FeeSettings.
+ *
+ * Zeroing `bytecodeSizeLimit` stops new uploads while leaving existing escrows
+ * finishable without forcing holders to wait for `CancelAfter`.
+ * Zeroing `gasLimit` stops both.
+ */
+/** @{ */
+inline bool
+isBytecodeUploadDisabled(Fees const& fees)
+{
+    return fees.bytecodeSizeLimit == 0 || fees.gasLimit == 0;
+}
+
+inline bool
+isBytecodeExecutionDisabled(Fees const& fees)
+{
+    return fees.gasLimit == 0;
+}
+/** @} */
+
+/**
+ * Owner count an escrow costs.
+ *
+ *  An escrow costs one increment per started 500 bytes of bytecode, and one
+ *  increment if it carries no bytecode.
+ */
+template <class T>
+int32_t
+calculateAdditionalReserve(T const& finishFunction)
+{
+    static auto constexpr kBytecodeReserveIncrement = 500;
+
+    if (!finishFunction)
+        return 1;
+
+    auto const size = finishFunction->size();
+    if (size == 0)
+    {
+        // LCOV_EXCL_START
+        // Empty Bytecode is refused at create, so no escrow carries it. Ceiling
+        // division would answer 0, which would subtract less than the create added.
+        UNREACHABLE("xrpl::calculateAdditionalReserve : empty Bytecode");
+        return 1;
+        // LCOV_EXCL_STOP
+    }
+
+    return static_cast<int32_t>((size + kBytecodeReserveIncrement - 1) / kBytecodeReserveIncrement);
+}
+
 }  // namespace xrpl

include/xrpl/ledger/helpers/LendingHelpers.h

@@ -7,10 +7,10 @@
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/ReadView.h>
+#include <xrpl/ledger/helpers/VaultHelpers.h>
 #include <xrpl/protocol/AccountID.h>
 #include <xrpl/protocol/Asset.h>
 #include <xrpl/protocol/LedgerFormats.h>  // IWYU pragma: keep
-#include <xrpl/protocol/Protocol.h>
 #include <xrpl/protocol/Rules.h>
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/STAmount.h>
@@ -31,9 +31,9 @@ namespace xrpl {
 /**
  * Broker cover preclaim precision guard (fixCleanup3_2_0).
  *
- * Prevents a "silent sub-ULP no-op" where a deposit, withdrawal, or clawback
- * amount is so small that it rounds to zero at `sfCoverAvailable`'s scale.
- * Without this guard, both the pseudo trust-line and `sfCoverAvailable` would
+ * Prevents a silent sub-ULP no-op where a deposit, withdrawal, or clawback
+ * amount is so small that it rounds to zero at sfCoverAvailable's scale.
+ * Without this guard, both the pseudo trust-line and sfCoverAvailable would
  * identically absorb the rounded zero, resulting in a successful transaction
  * (tesSUCCESS) where no funds actually moved.
  *
@@ -44,8 +44,8 @@ namespace xrpl {
  * @param j          Journal for logging.
  * @param logPrefix  Transactor name for log diagnostics.
  *
- * @return `tecPRECISION_LOSS` if the request rounds to zero at cover scale.
- * `tesSUCCESS` if the amendment is disabled or the request is safely supra-ULP.
+ * @return tecPRECISION_LOSS if the request rounds to zero at cover scale.
+ * tesSUCCESS if the amendment is disabled or the request is safely supra-ULP.
  */
 [[nodiscard]] TER
 canApplyToBrokerCover(
@@ -56,6 +56,82 @@ canApplyToBrokerCover(
     beast::Journal j,
     std::string_view logPrefix);
 
+namespace detail {
+
+/**
+ * Return a LoanBroker's posterior live cover exponent after applying an
+ * unrounded delta.
+ */
+[[nodiscard]] int
+getPosteriorBrokerCoverScale(SLE::ConstRef vault, SLE::ConstRef broker, Number const& delta);
+
+/**
+ * Round a cover outflow delta (cover withdraw, cover clawback, the
+ * broker-side decrease of a default's cover credit) at the LoanBroker's
+ * posterior live exponent. Safe to round the delta directly for an outflow:
+ * amount on the posterior grid of CoverAvailable always leaves CoverAvailable
+ * minus amount representable, since the posterior grid is exactly the grid
+ * CoverAvailable itself will canonicalize to after the subtraction.
+ */
+[[nodiscard]] STAmount
+roundToPosteriorBrokerCoverScale(
+    SLE::ConstRef vault,
+    SLE::ConstRef broker,
+    STAmount const& delta,
+    Number::RoundingMode roundingMode);
+
+}  // namespace detail
+
+/**
+ * Round a cover debit (cover withdraw, cover clawback, the broker-side
+ * decrease of a default's cover credit): amount is the non-negative
+ * magnitude leaving CoverAvailable. Negates so the posterior is computed for
+ * CoverAvailable minus amount, then negates the result back to a
+ * non-negative magnitude, per roundToPosteriorBrokerCoverScale's outflow
+ * rationale above. Magnitude in, magnitude out -- unlike the vault-side
+ * outflow dispatcher (clampVaultOutflow), which takes and returns a negative
+ * delta; callers on each side already hold the value in that side's native
+ * form.
+ */
+[[nodiscard]] STAmount
+debitToPosteriorBrokerCoverScale(
+    SLE::ConstRef vault,
+    SLE::ConstRef broker,
+    STAmount const& amount,
+    Number::RoundingMode roundingMode);
+
+/**
+ * Round a cover inflow (cover deposit, LoanPay's fee redirect into cover)
+ * into CoverAvailable by flooring the sum rather than the delta:
+ * credit = floor16(CoverAvailable + raw) - CoverAvailable, never finer
+ * than the Vault's base exponent (-Scale). See
+ * creditToPosteriorAvailableScale's doc for why the sum, not the delta,
+ * must be floored; the same reasoning applies to CoverAvailable.
+ */
+[[nodiscard]] STAmount
+creditToPosteriorBrokerCoverScale(
+    SLE::ConstRef vault,
+    SLE::ConstRef broker,
+    Number const& raw,
+    Number::RoundingMode roundingMode);
+
+/**
+ * Check whether amount is an admissible optional cover inflow.
+ *
+ * Legacy and CashBasis Vaults always succeed. A LoanBroker attached to a
+ * FixedPrecision Vault must remain at the Vault's base scale after applying
+ * the rounded amount, and its posterior CoverAvailable must stay within the
+ * Open zone.
+ *
+ * LoanPay's fee redirect into cover is a mandatory inflow and does not call
+ * this check, so it can push CoverAvailable past the Open zone limit this
+ * check enforces. Once that happens, every subsequent LoanBrokerCoverDeposit
+ * returns tecLIMIT_EXCEEDED until the owner withdraws cover back under the
+ * limit; LoanBrokerCoverWithdraw and LoanBrokerCoverClawback are unaffected.
+ */
+[[nodiscard]] TER
+checkOptionalBrokerCoverInflow(SLE::ConstRef vault, SLE::ConstRef broker, STAmount const& amount);
+
 // Lending protocol has dependencies, so capture them here.
 bool
 checkLendingProtocolDependencies(Rules const& rules, STTx const& tx);
@@ -64,13 +140,13 @@ checkLendingProtocolDependencies(Rules const& rules, STTx const& tx);
  * The accounts and asset that LoanManage::defaultLoan's fixCleanup3_4_0
  * freeze/lock exemption applies to.
  *
- * `defaultLoan` moves funds from the LoanBroker pseudo-account to the Vault
- * pseudo-account via `accountSend`. Since neither is the vault asset's
+ * defaultLoan moves funds from the LoanBroker pseudo-account to the Vault
+ * pseudo-account via accountSend. Since neither is the vault asset's
  * issuer, this is a third-party transfer that transits through the issuer in
  * two hops (broker -> issuer, issuer -> vault; see
- * `directSendNoLimitIOU`/`directSendNoLimitMPT`), so the exemption must cover
+ * directSendNoLimitIOU/directSendNoLimitMPT), so the exemption must cover
  * both the issuer/broker and issuer/vault pairs, not a direct broker/vault
- * pair. `asset` scopes it further to the vault's own currency/MPT issuance,
+ * pair. asset scopes it further to the vault's own currency/MPT issuance,
  * so an unrelated one the same accounts happen to hold is still protected.
  */
 struct LoanDefaultFreezeExemptAccounts
@@ -88,10 +164,10 @@ struct LoanDefaultFreezeExemptAccounts
  * @param view Ledger view used to resolve the Loan -> LoanBroker -> Vault
  * chain.
  * @param tx The transaction under invariant review.
- * @return The exempt accounts and asset if `tx` is a `ttLOAN_MANAGE`
- * transaction with the `tfLoanDefault` flag set, `fixCleanup3_4_0` is
+ * @return The exempt accounts and asset if tx is a ttLOAN_MANAGE
+ * transaction with the tfLoanDefault flag set, fixCleanup3_4_0 is
  * enabled, and the loan/broker/vault objects it references can all be
- * resolved; `std::nullopt` otherwise.
+ * resolved; std::nullopt otherwise.
  */
 [[nodiscard]] std::optional<LoanDefaultFreezeExemptAccounts>
 getLoanDefaultFreezeExemptAccounts(ReadView const& view, STTx const& tx);
@@ -254,28 +330,38 @@ adjustImpreciseNumber(
         value = 0;
 }
 
-inline int
-getAssetsTotalScale(SLE::ConstRef vaultSle)
-{
-    if (!vaultSle)
-        return Number::kMinExponent - 1;  // LCOV_EXCL_LINE
-    return scale(vaultSle->at(sfAssetsTotal), vaultSle->at(sfAsset));
-}
+/**
+ * Apply a signed delta to a LoanBroker's DebtTotal: on FixedPrecision Vaults,
+ * add the exact delta (DebtTotal moves by exactly the same amount as the
+ * Vault's AssetsDeployed, never re-rounded); on Legacy/CashBasis Vaults,
+ * round through adjustImpreciseNumber at vaultScale. Shared by LoanSet
+ * (origination) and LoanPay (payment, where delta is negative).
+ *
+ * @param brokerSle The LoanBroker whose DebtTotal is adjusted.
+ * @param vaultSle The LoanBroker's Vault.
+ * @param delta The signed change to DebtTotal.
+ * @param vaultScale The Vault scale the caller captured before changing
+ *        AssetsTotal. Legacy/CashBasis round DebtTotal at that scale, not at
+ *        the scale after this transaction's AssetsTotal change. Unused on
+ *        FixedPrecision Vaults.
+ */
+void
+adjustBrokerDebtTotal(
+    SLE::Ref brokerSle,
+    SLE::ConstRef vaultSle,
+    Number const& delta,
+    int vaultScale);
 
-// Compute the minimum required broker cover, rounded consistently.
-// DebtTotal is a broker-level aggregate maintained at vault scale, so the
-// rounding must also use vault scale — never an individual loan's scale.
-inline Number
-minimumBrokerCover(Number const& debtTotal, TenthBips32 coverRateMinimum, SLE::ConstRef vaultSle)
-{
-    XRPL_ASSERT(
-        vaultSle && vaultSle->getType() == ltVAULT, "xrpl::minimumBrokerCover : valid Vault sle");
-    NumberRoundModeGuard const mg(Number::RoundingMode::Upward);
-    return roundToAsset(
-        vaultSle->at(sfAsset),
-        tenthBipsOfValue(debtTotal, coverRateMinimum),
-        getAssetsTotalScale(vaultSle));
-}
+/**
+ * Minimum required broker cover, rounded up.
+ *
+ * DebtTotal is a broker-level aggregate, never rounded at an individual
+ * loan's scale. Legacy and CashBasis Vaults round at the live AssetsTotal
+ * exponent. FixedPrecision Vaults round at the Vault's base exponent
+ * (-Scale, or 0 for integral assets).
+ */
+Number
+minimumBrokerCover(Number const& debtTotal, TenthBips32 coverRateMinimum, SLE::ConstRef vaultSle);
 
 TER
 checkLoanGuards(
@@ -379,10 +465,10 @@ loanPaymentDeltas(LoanPaymentParts const& parts);
 
 }  // namespace cash_basis
 
-// Public dispatchers: pick cash_basis:: if featureLendingProtocolV1_1 is
-// enabled AND the Vault's LEVersion (VaultHelpers::getVaultVersion) is
-// VaultVersion::CashBasis, else instant_recognition::. These are the only entry points
-// transactors call.
+// Public dispatchers: pick cash_basis:: if the Vault's LEVersion
+// (VaultHelpers::getVaultVersion) is CashBasis or later (CashBasis or
+// FixedPrecision), else instant_recognition::. These are the only entry
+// points transactors call.
 AccountingDeltas
 loanOriginationDeltas(
     SLE::ConstRef vaultSle,

include/xrpl/ledger/helpers/MPTokenHelpers.h

@@ -312,12 +312,22 @@ checkCreateMPT(
 //
 //------------------------------------------------------------------------------
 
-// MaximumAmount doesn't exceed 2**63-1
+/**
+ * MaximumAmount doesn't exceed 2**63-1
+ */
 std::int64_t
 maxMPTAmount(SLE const& sleIssuance);
 
-// OutstandingAmount may overflow and available amount might be negative.
-// But available amount is always <= |MaximumAmount - OutstandingAmount|.
+/**
+ * std::nullopt if the issuance doesn't exist.
+ */
+std::optional<std::int64_t>
+maxMPTAmount(ReadView const& view, MPTID const& mptID);
+
+/**
+ * OutstandingAmount may overflow and available amount might be negative.
+ * But available amount is always <= |MaximumAmount - OutstandingAmount|.
+ */
 std::int64_t
 availableMPTAmount(SLE const& sleIssuance);
 
@@ -331,7 +341,12 @@ availableMPTAmount(ReadView const& view, MPTID const& mptID);
  * directSendNoFee transactions that bypass the payment engine.
  * 2.  **accountSend & Payment Engine (Overflow: Yes):** A temporary overflow
  * check when `OutstandingAmount > UINT64_MAX`. This higher threshold is used
- * for `accountSend` and payments processed via the payment engine.
+ * for `accountSend` and payments processed via the payment engine, whose
+ * reverse pass may issue before it redeems.
+ *
+ * In both cases a single `sendAmount > MaximumAmount` is rejected. Such a send
+ * can never settle: redemptions within the transaction are bounded by the
+ * outstanding amount, so the final OutstandingAmount would exceed the cap.
  */
 bool
 isMPTOverflow(
@@ -353,6 +368,12 @@ issuerFundsToSelfIssue(ReadView const& view, MPTIssue const& issue);
 /**
  * Facilitate tracking of MPT sold by an issuer owning MPT sell offer.
  * See ApplyView::issuerSelfDebitHookMPT().
+ *
+ * `amount` may be 0. BookStep removes an offer whose fee-adjusted funded
+ * output is 0, but other clips (for example MaximumAmount via limitStepIn)
+ * can still consume a zero slice of a funded remainder. The hook must
+ * accept 0: first call still snapshots origBalance; a zero debit adds
+ * nothing to selfDebit.
  */
 void
 issuerSelfDebitHookMPT(ApplyView& view, MPTIssue const& issue, std::uint64_t amount);

include/xrpl/ledger/helpers/ProposalHelpers.h

@@ -1,10 +1,17 @@
 #pragma once
 
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/ledger/ApplyView.h>
+#include <xrpl/ledger/ReadView.h>
 #include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STLedgerEntry.h>
 #include <xrpl/protocol/STObject.h>
+#include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/TxFormats.h>
 
 #include <cstdint>
+#include <optional>
 
 namespace xrpl::proposal {
 
@@ -30,31 +37,22 @@ proposalOwnerCount(STObject const& proposedTx)
                                                                 : kProposalOwnerCount;
 }
 
-/**
- * Whether the proposed transaction is itself a proposal transaction, which
- * would nest one proposal inside another.
- *
- * TODO: cover ttTRANSACTION_PROPOSAL_SIGN and ttTRANSACTION_PROPOSAL_CANCEL
- * once those transactions exist.
- */
-inline bool
-isProposalTx(STObject const& proposedTx)
-{
-    return proposedTx.getFieldU16(sfTransactionType) == ttTRANSACTION_PROPOSAL_CREATE;
-}
-
 /**
  * Whether the proposed transaction is independently submittable through the
- * ordinary multi-sign path: not a nested proposal, not a pseudo-transaction,
- * not itself flagged as someone else's inner batch transaction, and — if it
- * is a Batch — none of its own inner transactions is a nested proposal or a
- * pseudo-transaction either. A Batch inner transaction cannot itself be
- * pseudo (preflight0 rejects the pseudo/tfInnerBatchTxn combination
- * generically), but that guard lives outside this feature, so it is checked
- * again here rather than relied upon.
+ * ordinary multi-sign path: not a proposal transaction itself, not a
+ * pseudo-transaction, not itself flagged as someone else's inner batch
+ * transaction, and — if it is a Batch — every one of its own inner
+ * transactions carries a TransactionType and is neither a proposal, a
+ * pseudo-transaction, nor a nested Batch. A Batch inner transaction cannot
+ * lack a TransactionType, be pseudo, or be a nested Batch (STTx construction
+ * rejects a typeless inner and an inner Batch, and preflight0 rejects the
+ * pseudo/tfInnerBatchTxn combination), but those guards live outside this
+ * feature, so they are checked again here rather than relied upon.
+ *
+ * TODO: cover ttTRANSACTION_PROPOSAL_SIGN once that transaction exists.
  */
 bool
-isValidProposal(STObject const& proposedTx);
+isValidProposalTxnType(STObject const& proposedTx);
 
 /**
  * Whether the proposed transaction carries any signature field.
@@ -84,4 +82,93 @@ hasEmptySigningPubKey(STObject const& proposedTx)
         proposedTx.getFieldVL(sfSigningPubKey).empty();
 }
 
+/**
+ * Whether the proposal is terminal (On-Chain Cosigner spec §4.5). A terminal proposal
+ * stops accepting signatures and anyone may delete it. An already signed
+ * payload can still execute after Expiration, because the Ticket reservation
+ * compares payloads only; a passed LastLedgerSequence does stop it.
+ *
+ * A proposal is terminal when either:
+ * - its Expiration has passed (the parent ledger closed at or after it), or
+ * - the proposed transaction carries a LastLedgerSequence and the current
+ *   ledger sequence is strictly greater than it. This mirrors the ordinary
+ *   transactor's tefMAX_LEDGER rule: at view.seq() == LastLedgerSequence the
+ *   payload can still be submitted in the current ledger, so the proposal is
+ *   still live.
+ *
+ * @param view The ledger the deciding transaction is being applied to.
+ * @param expiration The proposal's Expiration field.
+ * @param proposedTx The proposal's ProposedTransaction field.
+ */
+bool
+isTerminal(
+    ReadView const& view,
+    std::optional<std::uint32_t> expiration,
+    STObject const& proposedTx);
+
+/**
+ * Delete a TransactionProposal ledger entry.
+ *
+ * Removes the entry from its Owner's directory, releases the reserve the
+ * proposal holds against the Owner, and erases the entry. Shared by every
+ * deletion path the spec defines (On-Chain Cosigner spec §4.5): automatic cleanup when the
+ * proposed transaction's TicketSequence is consumed, and the
+ * TransactionProposalCancel / TransactionProposalSign cleanup paths once
+ * those transactions exist.
+ *
+ * The release goes through decreaseOwnerCountForObject, so it follows the
+ * sfSponsor an entry created with reserve sponsorship carries: the reserve is
+ * returned to whoever was holding it, the Owner or that sponsor.
+ *
+ * @param view The apply view for making changes
+ * @param sleProposal The TransactionProposal ledger entry to delete
+ * @param j Journal for logging
+ * @return tesSUCCESS, tecINTERNAL for an invalid entry, or tefBAD_LEDGER if
+ *         the ledger contradicts the entry
+ */
+TER
+deleteProposal(ApplyView& view, SLE::pointer const& sleProposal, beast::Journal j);
+
+/**
+ * Whether tx carries the same payload as a proposal's stored
+ * ProposedTransaction (On-Chain Cosigner spec §4.2.1).
+ *
+ * The payload is the signing payload: the fields the collected signatures
+ * commit to. Compared is every field except those flagged kNotSigning
+ * (TxnSignature, Signers, BatchSigners, CounterpartySignature,
+ * SponsorSignature, Signature, MasterSignature) and SigningPubKey, which is
+ * stored empty and filled only if the target signs with its own key. So the
+ * completed transaction matches no matter which mix of collected or
+ * off-ledger signatures it carries, and any change to a non-signature field
+ * results in a false-return value.
+ *
+ * Signature (PaymentChannelClaim and the XChain attestation transactions)
+ * is deliberately not compared: it is outside the account's own TxnSignature
+ * even for an ordinary submission, so a proposal cannot bind it more tightly
+ * than the signatures it collects do, and those transactors still validate a
+ * substituted value exactly as they would for an ordinary submission.
+ * MasterSignature appears in no transaction format.
+ *
+ * @param proposedTx The proposal's ProposedTransaction field.
+ * @param tx The transaction to compare, typically an STTx.
+ */
+bool
+payloadMatches(STObject const& proposedTx, STObject const& tx);
+
+/**
+ * Whether tx may consume its Ticket.
+ *
+ * While a proposal keyed to the Ticket exists, the target's Ticket is
+ * reserved: only the proposal's own proposed transaction may spend it
+ * (On-Chain Cosigner spec §4.2.1), so that unrelated target-account activity cannot
+ * invalidate the proposal while signatures are being collected.
+ * TransactionProposalCancel is not allowed through: it deletes the
+ * reservation without consuming the ticket.
+ *
+ * @param view The ledger containing the Ticket and any reservation.
+ * @param tx The transaction attempting to consume that ticket.
+ */
+bool
+canConsumeTicket(ReadView const& view, STTx const& tx);
+
 }  // namespace xrpl::proposal

include/xrpl/ledger/helpers/TokenHelpers.h

@@ -316,6 +316,20 @@ transferRate(ReadView const& view, Asset const& asset);
 [[nodiscard]] Rate
 transferRate(ReadView const& view, STAmount const& amount);
 
+/**
+ * Returns the amount a sender must part with for `amount` to reach the
+ * receiver once the issuer takes the transfer fee. Rounds up.
+ */
+[[nodiscard]] STAmount
+addTransferFee(STAmount const& amount, Rate const& rate);
+
+/**
+ * Returns the amount a receiver gets when `amount` leaves the sender and the
+ * issuer takes the transfer fee. Rounds down.
+ */
+[[nodiscard]] STAmount
+subtractTransferFee(STAmount const& amount, Rate const& rate);
+
 //------------------------------------------------------------------------------
 //
 // Holding operations (Asset-based dispatchers)

include/xrpl/ledger/helpers/VaultHelpers.h

@@ -1,10 +1,12 @@
 #pragma once
 
 #include <xrpl/basics/Number.h>
+#include <xrpl/beast/utility/Journal.h>
 #include <xrpl/ledger/ReadView.h>
 #include <xrpl/protocol/AccountID.h>
 #include <xrpl/protocol/Asset.h>
 #include <xrpl/protocol/Protocol.h>
+#include <xrpl/protocol/Rules.h>
 #include <xrpl/protocol/STAmount.h>
 #include <xrpl/protocol/STLedgerEntry.h>
 #include <xrpl/protocol/TER.h>
@@ -12,11 +14,239 @@
 #include <cstdint>
 #include <expected>
 #include <optional>
+#include <string_view>
 
 namespace xrpl {
 
 class STTx;
 
+/**
+ * @brief Return the Vault's current assets total.
+ *
+ * FixedPrecision Vaults return AssetsAvailable plus AssetsDeployed, with no
+ * rounding to the asset's 16-digit precision: the sum is exact at Number's
+ * active 19-digit mantissa width (the large mantissa range, enabled by
+ * featureSingleAssetVault or featureLendingProtocol), rounds Downward regardless of the
+ * caller's ambient mode beyond that, and is not rounded to match the cached
+ * sfAssetsTotal field. Legacy and CashBasis Vaults return the stored
+ * AssetsTotal.
+ *
+ * @param vault The vault SLE.
+ * @return The current assets total.
+ */
+[[nodiscard]] Number
+getAssetsTotal(SLE::ConstRef vault);
+
+/**
+ * @brief A change to a FixedPrecision Vault's balances.
+ */
+struct VaultBalanceChange
+{
+    /**
+     * Signed change to AssetsAvailable. Must be the exact amount moved on the
+     * Vault pseudo-account in the same transaction. Absent means no cash
+     * moved; adjustVaultBalances then uses zero of the Vault's own asset.
+     */
+    std::optional<STAmount> cash = std::nullopt;
+
+    /**
+     * Signed change to AssetsDeployed: open Loan principal, exact.
+     */
+    Number deployed = 0;
+
+    /**
+     * Signed change to scheduled, unpaid interest (YieldUnrealized), exact.
+     */
+    Number yield = 0;
+
+    /**
+     * Signed change to impaired principal (LossUnrealized), exact.
+     */
+    Number loss = 0;
+};
+
+/**
+ * @brief Apply a balance change to a FixedPrecision Vault. The only writer of
+ * AssetsAvailable, AssetsDeployed, AssetsTotal, YieldUnrealized and
+ * LossUnrealized on these Vaults after creation.
+ *
+ * @param vault The vault SLE. Must be FixedPrecision.
+ * @param change The balance change to apply.
+ * @param j Journal for logging the fatal (tefBAD_LEDGER) case.
+ *
+ * @return tesSUCCESS; tecLIMIT_EXCEEDED if LossUnrealized would exceed
+ *         AssetsDeployed; tefBAD_LEDGER if AssetsAvailable, AssetsDeployed,
+ *         LossUnrealized or YieldUnrealized would become negative.
+ */
+[[nodiscard]] TER
+adjustVaultBalances(SLE::Ref vault, VaultBalanceChange const& change, beast::Journal j);
+
+/**
+ * @brief Apply a signed cash movement to a Vault of any version. FixedPrecision
+ * Vaults go through adjustVaultBalances; Legacy and CashBasis Vaults add the
+ * amount to both AssetsTotal and AssetsAvailable.
+ *
+ * @param vault The vault SLE.
+ * @param delta Signed change to AssetsAvailable; the exact amount moved on the
+ *              Vault pseudo-account.
+ * @param j Journal passed through to adjustVaultBalances.
+ *
+ * @return tesSUCCESS, or the adjustVaultBalances error for FixedPrecision Vaults.
+ */
+[[nodiscard]] TER
+adjustVaultCash(SLE::Ref vault, STAmount const& delta, beast::Journal j);
+
+/**
+ * Return the Vault's current live exponent.
+ *
+ * Legacy and CashBasis Vaults use the exponent of AssetsTotal. FixedPrecision
+ * Vaults use max(base exponent, exponent of AssetsTotal): the grid is never
+ * finer than -Scale and coarsens once AssetsTotal outgrows 16 digits there.
+ */
+[[nodiscard]] int
+getVaultScale(SLE::ConstRef vault);
+
+/**
+ * Return the Vault's base exponent.
+ *
+ * Legacy and CashBasis Vaults use their current live exponent. FixedPrecision
+ * Vaults use -Scale, or 0 for integral assets.
+ */
+[[nodiscard]] int
+getVaultBaseScale(SLE::ConstRef vault);
+
+/**
+ * Round an amount at the Vault's posterior live exponent.
+ */
+[[nodiscard]] STAmount
+roundToPosteriorVaultScale(
+    SLE::ConstRef vault,
+    STAmount const& amount,
+    Number::RoundingMode roundingMode);
+
+namespace detail {
+
+/**
+ * Return the Vault's posterior live exponent after applying an unrounded delta.
+ */
+[[nodiscard]] int
+getPosteriorVaultScale(SLE::ConstRef vault, STAmount const& delta);
+
+/**
+ * Shared grid-floor core of getVaultScale / getPosteriorVaultScale /
+ * getPosteriorBrokerCoverScale: baseScale when reference is zero, otherwise
+ * max(baseScale, scale(reference, asset)), rounded Downward regardless of
+ * the caller's ambient rounding mode.
+ */
+[[nodiscard]] int
+liveScale(Number const& reference, Asset const& asset, int baseScale);
+
+/**
+ * Shared core of getPosteriorVaultScale and getPosteriorBrokerCoverScale:
+ * the exponent reference + delta would have under version's live-scale rule
+ * (floored at baseScale for FixedPrecision, unbounded for Legacy/CashBasis).
+ *
+ * @param version The Vault's LEVersion.
+ * @param asset The Vault's underlying asset.
+ * @param baseScale The Vault's base exponent; unused outside the
+ *                   FixedPrecision case.
+ * @param reference The balance the delta is applied to (AssetsAvailable,
+ *                   AssetsTotal, or a LoanBroker's CoverAvailable).
+ * @param delta The unrounded change to reference.
+ */
+[[nodiscard]] int
+posteriorAssetScale(
+    VaultVersion version,
+    Asset const& asset,
+    int baseScale,
+    Number const& reference,
+    Number const& delta);
+
+/**
+ * Shared core of creditToPosteriorAvailableScale and
+ * creditToPosteriorBrokerCoverScale: floors reference + raw at the sum's
+ * own live scale (never finer than baseScale) and returns the difference
+ * from reference, so the delta applied is exactly what moves reference onto
+ * the floored sum. See creditToPosteriorAvailableScale's doc for why the
+ * sum, not raw alone, must be floored. raw is the exact amount; it is not
+ * rounded on its own before being added to reference. The sum and its scale
+ * are computed once, in roundingMode, so a Downward credit is always
+ * between zero and raw.
+ */
+[[nodiscard]] STAmount
+creditToPosteriorScale(
+    Asset const& asset,
+    Number const& reference,
+    int baseScale,
+    Number const& raw,
+    Number::RoundingMode roundingMode);
+
+}  // namespace detail
+
+/**
+ * Round a FixedPrecision cash inflow (LoanPay's credit, LoanManage's
+ * default cover credit) into AssetsAvailable, never AssetsTotal, which is
+ * a derived cache, by flooring the sum rather than the delta:
+ * credit equals floor16(AssetsAvailable + raw) minus AssetsAvailable, never
+ * finer than the Vault's base exponent (-Scale).
+ *
+ * Flooring only the delta at its own posterior grid is not enough: the sum
+ * can still need a 17th digit when AssetsAvailable is off the coarser grid
+ * right after crossing a power of ten. Example at Scale 6: AssetsAvailable
+ * equals 9999999999.999999 (16 digits already) and a credit of 0.000011
+ * floors to 0.00001 on its own (finer) grid, but 9999999999.999999 plus
+ * 0.00001 equals 10000000000.000009, which still needs 17 digits. Flooring
+ * the sum instead, floor16(9999999999.999999 + 0.000011) minus
+ * 9999999999.999999, is exact by construction, since STAmount's own
+ * 16-digit canonical form of the sum is what gets subtracted from.
+ *
+ * raw is taken as an exact Number: rounding it to 16 digits before adding
+ * it to AssetsAvailable could drop a tail that moves the floored sum.
+ */
+[[nodiscard]] STAmount
+creditToPosteriorAvailableScale(
+    SLE::ConstRef vault,
+    Number const& raw,
+    Number::RoundingMode roundingMode);
+
+/**
+ * Open-zone capacity ceiling: 9 * 10^(15 + baseScale).
+ *
+ * Defined only for FixedPrecision Vaults, where this is 9 * 10^(15 - P).
+ */
+[[nodiscard]] Number
+getVaultOpenLimit(SLE::ConstRef vault);
+
+/**
+ * Check whether amount is an admissible optional inflow.
+ *
+ * Legacy and CashBasis Vaults always succeed. FixedPrecision Vaults must
+ * remain at their base scale after applying the rounded amount, and the
+ * posterior capacity (AssetsTotal + YieldUnrealized + rounded amount) must
+ * stay within the Open zone.
+ *
+ * The amount is rounded toward zero at the posterior live exponent.
+ */
+[[nodiscard]] TER
+checkOptionalVaultInflow(SLE::ConstRef vault, STAmount const& amount);
+
+/**
+ * Open-zone capacity after adding roundedAmount: AssetsTotal + YieldUnrealized
+ * + roundedAmount, computed TowardsZero regardless of the caller's ambient
+ * rounding mode. Defined only for FixedPrecision Vaults.
+ *
+ * Shared by checkOptionalVaultInflow and LoanSet's loan-origination capacity
+ * check, which pair this formula with different scale checks (posterior vs.
+ * current), so only the capacity formula itself -- not the whole check -- is
+ * shared here.
+ *
+ * @param vault The vault SLE. Must be FixedPrecision.
+ * @param roundedAmount The amount to add, already rounded to the relevant
+ *                       posterior or base scale by the caller.
+ */
+[[nodiscard]] Number
+vaultOpenZoneCapacity(SLE::ConstRef vault, Number const& roundedAmount);
+
 /**
  * From the perspective of a vault, return the number of shares to give
  * depositor when they offer a fixed amount of assets. Note, since shares are
@@ -46,31 +276,93 @@ assetsToSharesDeposit(SLE::ConstRef vault, SLE::ConstRef issuance, STAmount cons
 sharesToAssetsDeposit(SLE::ConstRef vault, SLE::ConstRef issuance, STAmount const& shares);
 
 /**
- * Adjusts a requested asset change (`delta`) to match the decimal scale of the
- * updated total vault assets. This ensures `sfAssetsTotal`, `sfAssetsAvailable`,
+ * Adjusts a requested asset change (delta) to match the decimal scale of the
+ * updated total vault assets. This ensures sfAssetsTotal, sfAssetsAvailable,
  * and the actual asset transfer change by the exact same representable amount.
  *
  * Rounding strategy:
- * - Debits (withdrawals): Rounds down `|delta|` on the new scale to prevent
- *   paying out more than requested.
- * - Credits (deposits): Floors the resulting total asset balance and returns the
- *   difference from the current total. This prevents crediting the vault with
- *   more assets than the user deposited.
+ * - Legacy/CashBasis debits (withdrawals): rounds down the magnitude of delta
+ *   on the new scale to prevent paying out more than requested.
+ * - Legacy/CashBasis credits: floors the resulting total asset balance and
+ *   returns the difference from the current total.
+ * - FixedPrecision credits only (VaultDeposit): rounds the delta toward zero
+ *   at the scale getAssetsTotal (AssetsAvailable + AssetsDeployed, derived,
+ *   not the stored AssetsTotal cache) would have after applying delta.
+ *   FixedPrecision outflows (VaultWithdraw, VaultClawback) never call this;
+ *   they use clampVaultOutflow instead.
  *
  * Key rules:
- * - The returned magnitude never exceeds `|delta|`.
- * - Returns `tecPRECISION_LOSS` if the change is smaller than 1 ULP of the target scale
+ * - The returned magnitude never exceeds the magnitude of delta.
+ * - Returns tecPRECISION_LOSS if the change is smaller than 1 ULP of the target scale
  *   (prevents share operations when totals cannot change).
  * - For integer assets (XRP, MPT), rounding is a no-op.
  *
  * @param vault The vault ledger entry.
  * @param delta The requested signed change to sfAssetsTotal.
- * @return The rounded, positive magnitude, or `tecPRECISION_LOSS` if the
+ * @return The rounded, positive magnitude, or tecPRECISION_LOSS if the
  *         change is below representable precision.
  */
 [[nodiscard]] std::expected<STAmount, TER>
 clampToAssetsTotalScale(SLE::ConstRef vault, STAmount const& delta);
 
+/**
+ * Outflow clamp dispatcher for VaultWithdraw and VaultClawback: rounds a
+ * negative delta to the scale appropriate for the Vault's version -- for
+ * FixedPrecision, at AssetsAvailable's own posterior scale (the balance the
+ * cash actually leaves); for Legacy/CashBasis, clampToAssetsTotalScale --
+ * so both call sites share one dispatch point. Same tecPRECISION_LOSS and
+ * integral-asset and magnitude-never-exceeds-delta rules as
+ * clampToAssetsTotalScale.
+ *
+ * @param vault The vault ledger entry.
+ * @param delta The requested signed outflow (negative).
+ * @return The rounded, positive magnitude, or tecPRECISION_LOSS if the
+ *         change is below representable precision.
+ */
+[[nodiscard]] std::expected<STAmount, TER>
+clampVaultOutflow(SLE::ConstRef vault, STAmount const& delta);
+
+/**
+ * Returns the Vault's base exponent for asset at scale, before a Vault
+ * object exists to read it from: 0 for an integral asset, -scale otherwise.
+ * Used by VaultCreate::preclaim, which only has the proposed Scale field,
+ * not yet a Vault SLE; getVaultBaseScale is the post-creation equivalent.
+ *
+ * @param asset The (prospective) Vault's underlying asset.
+ * @param scale The (prospective) Vault's sfScale value, ignored for
+ *              integral assets.
+ */
+[[nodiscard]] int
+vaultBaseScale(Asset const& asset, std::uint8_t scale);
+
+/**
+ * Returns true iff value is exactly representable both as an STAmount of
+ * asset and on the base grid at baseScale (no precision lost rounding
+ * TowardsZero at baseScale). Returns false, rather than throwing, for a value
+ * out of range for the asset. Shared representability check for
+ * VaultCreate::preclaim, VaultSet::preclaim and LoanBrokerSet::preclaim's
+ * AssetsMaximum / DebtMaximum / cover-rate field checks.
+ *
+ * @param asset The vault's underlying asset.
+ * @param value The value to check.
+ * @param baseScale The vault's base exponent (see vaultBaseScale /
+ *                  getVaultBaseScale).
+ */
+[[nodiscard]] bool
+isOnVaultBaseGrid(Asset const& asset, Number const& value, int baseScale);
+
+/**
+ * Checks that a requested AssetsMaximum is exactly representable on the
+ * Vault's base grid, otherwise associateAsset would silently round the cap
+ * the owner asked for. Used by VaultSet::preclaim on an existing Vault.
+ *
+ * @param vault The vault ledger entry.
+ * @param amount The requested AssetsMaximum.
+ * @return tesSUCCESS, or tecPRECISION_LOSS if amount is not representable.
+ */
+[[nodiscard]] TER
+checkAssetsMaximum(SLE::ConstRef vault, Number const& amount);
+
 /**
  * Controls whether to truncate shares instead of rounding.
  */
@@ -98,21 +390,24 @@ enum class WaiveUnrealizedLoss : bool { No = false, Yes = true };
 assetsTotalForWithdrawal(SLE::ConstRef vault, WaiveUnrealizedLoss waive);
 
 /**
- * Returns true if debiting `amount` from `total` (the current value of a
- * vault's sfAssetsTotal or sfAssetsAvailable) would canonicalize to the
- * same STAmount value. This happens when `amount` is non-zero but too small
- * to change the stored total at STAmount's precision. Shares would still
- * move, so the ValidVault invariant would fail after apply; callers use
- * this to reject the transaction upfront instead.
+ * Reject a cash outflow that is dust (see debitIsNonZeroDust) or whose check
+ * overflows Number, which is easy to hit with a large Scale.
  *
- * @param asset The vault's underlying asset, used to canonicalize both
- *              sides the same way the ledger will when the field is stored.
- * @param total The field's current value.
- * @param amount The amount to debit. Zero always returns false; that case
- *               is rejected separately.
+ * @param vault The vault SLE.
+ * @param amount The amount to debit.
+ * @param j Journal for the debug log.
+ * @param name Transaction name used as the log prefix.
+ *
+ * @return tesSUCCESS; tecPRECISION_LOSS if amount is dust; tecPATH_DRY if the
+ *         check overflows. Overflow means the transaction cannot apply, but
+ *         ledger state is still consistent.
  */
-[[nodiscard]] bool
-debitIsNonZeroDust(Asset const& asset, Number const& total, Number const& amount);
+[[nodiscard]] TER
+checkDebitNotDust(
+    SLE::ConstRef vault,
+    Number const& amount,
+    beast::Journal j,
+    std::string_view name);
 
 /**
  * From the perspective of a vault, return the number of shares to demand from
@@ -158,7 +453,7 @@ sharesToAssetsWithdraw(
     WaiveUnrealizedLoss waive = WaiveUnrealizedLoss::No);
 
 /**
- * Returns true iff `account` holds all of the vault's outstanding shares —
+ * Returns true iff account holds all of the vault's outstanding shares,
  * i.e. is the sole remaining shareholder. Returns false if the account
  * holds no shares or fewer than the total outstanding.
  *
@@ -171,11 +466,13 @@ sharesToAssetsWithdraw(
 isSoleShareholder(ReadView const& view, AccountID const& account, SLE::ConstRef issuance);
 
 /**
- * Resolves a Vault's LEVersion, the single point every accounting touch
- * point should call to determine which recognition model (instant interest
- * recognition vs. cash-basis) a Vault uses. Vaults created before featureLendingProtocolV1_1
- * activated never have sfLEVersion set, which resolves here to
- * VaultVersion::Legacy.
+ * Resolves a Vault's LEVersion.
+ *
+ * LEVersion is the single point every accounting and rounding helper
+ * should call to decide which protocol a Vault follows. It is written
+ * at VaultCreate and is not updated afterwards, so a Vault created
+ * under an older amendment keeps that behaviour after later amendments
+ * activate. Absent sfLEVersion resolves to VaultVersion::Legacy.
  *
  * @param vault The vault SLE.
  *
@@ -185,6 +482,34 @@ isSoleShareholder(ReadView const& view, AccountID const& account, SLE::ConstRef
 [[nodiscard]] VaultVersion
 getVaultVersion(SLE::ConstRef vault);
 
+/**
+ * Decodes an already-extracted sfLEVersion value with the same range check as
+ * getVaultVersion. Usable from contexts, such as an invariant's ledger-entry
+ * snapshot, that keep the field value but not the owning SLE.
+ *
+ * @param leVersion The value of sfLEVersion, or nullopt if absent.
+ *
+ * @return The decoded LEVersion, or VaultVersion::Legacy if absent.
+ */
+[[nodiscard]] VaultVersion
+decodeVaultVersion(std::optional<std::uint8_t> leVersion);
+
+/**
+ * Resolves which LEVersion a newly-created Vault should get under the
+ * currently active amendments. This is the only place that decides Vault
+ * version policy; VaultCreate calls it instead of checking amendments
+ * directly.
+ *
+ * @param rules The active ledger rules.
+ *
+ * @return VaultVersion::FixedPrecision once featureLendingProtocolV1_1,
+ * featureLendingProtocolV1_2 and fixCleanup3_4_0 are all enabled;
+ * VaultVersion::CashBasis
+ * once featureLendingProtocolV1_1 is enabled; VaultVersion::Legacy otherwise.
+ */
+[[nodiscard]] VaultVersion
+getVaultDefaultVersion(Rules const& rules);
+
 /**
  * Resolves the VaultKind of a vault SLE. Returns VaultKind::ClosedEnded when
  * sfVaultKind is present and equal to that value; anything else (including an

include/xrpl/protocol/ApiVersion.h

@@ -6,21 +6,31 @@
 #include <xrpl/protocol/jss.h>
 
 #include <cstddef>
-#include <string_view>
 #include <type_traits>
 #include <utility>
 
 namespace xrpl {
 
 /**
- * The `api_version` numbers this server serves.
+ * API version numbers used in later API versions
  *
- * A request naming a version in [kApiMinimumSupportedVersion,
- * kApiMaximumSupportedVersion] is served. With `[beta_rpc_api]` set to `1` in
- * the config the range extends to kApiBetaVersion.
+ * Requests with a version number in the range
+ * [apiMinimumSupportedVersion, apiMaximumSupportedVersion]
+ * are supported.
  *
- * A request naming no version is served at kApiVersionIfUnspecified, which is 1
- * because a request wanting any later version states it.
+ * If [beta_rpc_api] is enabled in config, the version numbers
+ * in the range [apiMinimumSupportedVersion, apiBetaVersion]
+ * are supported.
+ *
+ * Network Requests without explicit version numbers use
+ * apiVersionIfUnspecified. apiVersionIfUnspecified is 1,
+ * because all the RPC requests with a version >= 2 must
+ * explicitly specify the version in the requests.
+ * Note that apiVersionIfUnspecified will be lower than
+ * apiMinimumSupportedVersion when we stop supporting API
+ * version 1.
+ *
+ * Command line Requests use apiCommandLineVersion.
  */
 
 namespace rpc {
@@ -47,16 +57,6 @@ static_assert(kApiMaximumSupportedVersion >= kApiMinimumSupportedVersion);
 static_assert(kApiBetaVersion >= kApiMaximumSupportedVersion);
 static_assert(kApiMaximumValidVersion >= kApiMaximumSupportedVersion);
 
-/**
- * Values accepted in the `ripplerpc` request field, which selects the shape of
- * the JSON-RPC reply envelope. Distinct from `kJsonRpcVersion` in JsonRpc.h,
- * which names the JSON-RPC protocol itself, and from the `api_version`
- * constants above, which select the content of the response.
- */
-inline constexpr std::string_view kRippleRpcVersion1{"1.0"};
-inline constexpr std::string_view kRippleRpcVersion2{"2.0"};
-inline constexpr std::string_view kRippleRpcVersion3{"3.0"};
-
 inline void
 setVersion(json::Value& parent, unsigned int apiVersion, bool betaEnabled)
 {

include/xrpl/protocol/ConfidentialTransfer.h

@@ -348,16 +348,19 @@ isAuditorMirrorCurrent(SLE const& issuance, SLE const& mptoken);
 areMirrorsCurrent(SLE const& issuance, SLE const& mptoken);
 
 /**
- * @brief Set the holder's issuer mirror epoch to match the issuance's current issuer key epoch.
+ * @brief Set the holder's issuer mirror epoch, and the issuer mirror key, to match the issuance's
+ * current key.
  *
  * Call this after writing the issuer mirror ciphertext under the issuance's
  * currently registered issuer key, so that the mirror reads as current afterwards.
+ * Also records sfIssuerMirrorEncryptionKey as the issuance's current issuer key
+ * (both fields stay absent at epoch 0, where the original issuer key applies).
  *
  * @param issuance The MPTokenIssuance ledger object.
  * @param mptoken  The holder's MPToken ledger entry to update.
  */
 void
-setIssuerMirrorEpoch(SLE const& issuance, SLE& mptoken);
+setIssuerMirrorCurrent(SLE const& issuance, SLE& mptoken);
 
 /**
  * @brief Set the holder's auditor mirror epoch to match the issuance's current auditor key epoch.
@@ -372,16 +375,18 @@ void
 setAuditorMirrorEpoch(SLE const& issuance, SLE& mptoken);
 
 /**
- * @brief Set the holder's MPToken mirror epochs to match the issuance's current key epochs.
+ * @brief Set the holder's MPToken mirror epochs, and the issuer mirror key, to match the issuance's
+ * current keys.
  *
  * Call this after writing mirror ciphertexts under the issuance's currently
- * registered keys, so that the mirrors read as current afterwards.
+ * registered keys, so that the mirrors read as current afterwards. Also records
+ * sfIssuerMirrorEncryptionKey via setIssuerMirrorCurrent.
  *
  * @param issuance The MPTokenIssuance ledger object.
  * @param mptoken  The holder's MPToken ledger entry to update.
  */
 void
-setMirrorEpochs(SLE const& issuance, SLE& mptoken);
+setMirrorsCurrent(SLE const& issuance, SLE& mptoken);
 
 /**
  * @brief Verifies revealed amount encryptions for all recipients.

include/xrpl/protocol/ErrorCodes.h

@@ -180,6 +180,11 @@ struct ErrorInfo
     {
     }
 
+    constexpr ErrorInfo(ErrorCodeI code, char const* token, char const* message)
+        : code(code), token(token), message(message), httpStatus(200)
+    {
+    }
+
     constexpr ErrorInfo(ErrorCodeI code, char const* token, char const* message, int httpStatus)
         : code(code), token(token), message(message), httpStatus(httpStatus)
     {

include/xrpl/protocol/Fees.h

@@ -10,6 +10,25 @@ namespace xrpl {
 // This was the reference fee units used in the old fee calculation.
 inline constexpr std::uint32_t kFeeUnitsDeprecated = 10;
 
+// Number of micro-drops in one drop.
+inline constexpr std::uint32_t microDropsPerDrop{1'000'000};
+
+/**
+ * Hard protocol bounds on the Feature Extension fee settings. A voted value
+ * can never fall outside these, so `preflight`, which has no view, may bound
+ * against them. Gas and bytecode limits are capped; gas price has a floor
+ * (zero would make WASM execution effectively free).
+ */
+inline constexpr std::uint32_t kMaxGasLimit{2'000'000};
+inline constexpr std::uint32_t kMaxBytecodeSizeLimit{200'000};
+inline constexpr std::uint32_t kMinGasPrice{1};
+
+// The following default values of fee settings will seed into FeeSettings
+// and write to the ledger on featureSmartEscrow activation.
+inline constexpr std::uint32_t kDefaultGasLimit{1'000'000};
+inline constexpr std::uint32_t kDefaultBytecodeSizeLimit{100'000};
+inline constexpr std::uint32_t kDefaultGasPrice{1'000'000};
+
 /**
  * Reflects the fee settings for a particular ledger.
  *
@@ -33,13 +52,47 @@ struct Fees
      */
     XRPAmount increment{0};
 
+    /**
+     * @brief Gas limit for Feature Extensions (instructions).
+     *
+     * This and the one below default to the protocol values rather than 0,
+     * because an explicit 0 is the voted kill switch.
+     */
+    std::uint32_t gasLimit{kDefaultGasLimit};
+
+    /**
+     * @brief Bytecode size limit for Feature Extensions (bytes).
+     */
+    std::uint32_t bytecodeSizeLimit{kDefaultBytecodeSizeLimit};
+
+    /**
+     * @brief Price of WASM gas (micro-drops).
+     */
+    std::uint32_t gasPrice{kDefaultGasPrice};
+
     explicit Fees() = default;
     Fees(Fees const&) = default;
     Fees&
     operator=(Fees const&) = default;
 
     Fees(XRPAmount base, XRPAmount reserve, XRPAmount increment)
-        : base(base), reserve(reserve), increment(increment)
+        : base{base}, reserve{reserve}, increment{increment}
+    {
+    }
+
+    Fees(
+        XRPAmount base,
+        XRPAmount reserve,
+        XRPAmount increment,
+        std::uint32_t gasLimit,
+        std::uint32_t bytecodeSizeLimit,
+        std::uint32_t gasPrice)
+        : base{base}
+        , reserve{reserve}
+        , increment{increment}
+        , gasLimit{gasLimit}
+        , bytecodeSizeLimit{bytecodeSizeLimit}
+        , gasPrice{gasPrice}
     {
     }
 

include/xrpl/protocol/JsonRpc.h

@@ -1,20 +0,0 @@
-#pragma once
-
-#include <string_view>
-
-namespace xrpl::rpc {
-
-/**
- * Constants of the JSON-RPC 2.0 protocol itself.
- *
- * Kept apart from the `api_version` and `ripplerpc` constants in ApiVersion.h,
- * which go when support for API versions 1 and 2 goes.
- */
-
-/**
- * Value of the `jsonrpc` member of a request and of its reply, fixed at "2.0"
- * by the JSON-RPC specification.
- */
-inline constexpr std::string_view kJsonRpcVersion{"2.0"};
-
-}  // namespace xrpl::rpc

include/xrpl/protocol/Protocol.h

@@ -311,24 +311,46 @@ constexpr std::uint8_t kVaultStrategyFirstComeFirstServe = 1;
  * Default IOU scale factor for a Vault
  */
 constexpr std::uint8_t kVaultDefaultIouScale = 6;
-/**
- * Maximum scale factor for a Vault. The number is chosen to ensure that
- * 1 IOU can be always converted to shares.
- * 10^19 > maxMPTokenAmount (2^64-1) > 10^18
- */
-constexpr std::uint8_t kVaultMaximumIouScale = 18;
 
 /**
- * Vault ledger-entry schema versions. Assigned to newly created
- * Vaults once featureLendingProtocolV1_1 is enabled. Vaults created before
- * activation are left without LEVersion (implicit legacy version 0,
- * instant interest recognition).
+ * Maximum Scale for a Vault created before featureLendingProtocolV1_2.
+ * Chosen so 1 IOU can always convert to shares:
+ * 10^19 > maxMPTokenAmount (2^64-1) > 10^18.
+ */
+constexpr std::uint8_t kLegacyVaultMaximumIouScale = 18;
+
+/**
+ * Maximum Scale for a Vault created under featureLendingProtocolV1_2.
+ */
+constexpr std::uint8_t kFixedPrecisionVaultMaximumIouScale = 10;
+
+/**
+ * Vault ledger-entry schema versions, persisted as sfLEVersion.
+ *
+ * LEVersion records which protocol a Vault was created under so later
+ * amendments can change the rules for new Vaults without rewriting
+ * existing ones. VaultCreate writes it from the then-active lending
+ * amendments; later transactions do not update it. A Vault created
+ * under an older amendment keeps that amendment's behaviour for its
+ * lifetime, even after a newer lending amendment activates.
+ *
+ * Absent sfLEVersion is implicit Legacy (version 0): instant interest
+ * recognition and a dynamic AssetsTotal scale. CashBasis (V1.1) uses
+ * cash-basis recognition on the same dynamic scale. FixedPrecision
+ * (V1.2) keeps cash-basis recognition and adds the lifetime base grid.
  */
 enum class VaultVersion : uint8_t {
     Legacy = 0,
     CashBasis,
+    FixedPrecision,
 };
 
+// Code compares VaultVersion values with < and >= (e.g. "CashBasis or later"),
+// so each later version must stay numerically larger than the one before.
+static_assert(
+    VaultVersion::Legacy < VaultVersion::CashBasis &&
+    VaultVersion::CashBasis < VaultVersion::FixedPrecision);
+
 /**
  * Vault kind. Distinguishes closed-ended vaults from the default open-ended
  * kind. Persisted as sfVaultKind (UINT8); absent means OpenEnded.
@@ -376,6 +398,11 @@ constexpr std::uint32_t kMaxInvestmentPeriod = std::chrono::seconds{std::chrono:
  */
 constexpr std::uint8_t kMaxAssetCheckDepth = 5;
 
+/**
+ * Maximum length of a Data field in Escrow object that can be updated by WASM code.
+ */
+constexpr std::size_t kMaxWasmDataLength = 1 * 1024;  // 1KB
+
 /**
  * A ledger index.
  */

include/xrpl/protocol/STAmount.h

@@ -696,6 +696,16 @@ divRound(STAmount const& v1, STAmount const& v2, Asset const& asset, bool roundU
 STAmount
 divRoundStrict(STAmount const& v1, STAmount const& v2, Asset const& asset, bool roundUp);
 
+/**
+ * Returns amt * num / den, rounded in the requested direction.
+ *
+ * Dispatches to the XRPAmount, IOUAmount or MPTAmount overload. XRP and MPT
+ * results are exact; an IOU result is rounded to the 16-digit mantissa in the
+ * requested direction. Only Upward and Downward are supported.
+ */
+[[nodiscard]] STAmount
+mulRatio(STAmount const& amt, std::uint32_t num, std::uint32_t den, Number::RoundingMode rounding);
+
 // Someone is offering X for Y, what is the rate?
 // Rate: smaller is better, the taker wants the most out: in/out
 // VFALCO TODO Return a Quality object
@@ -766,6 +776,21 @@ roundToAsset(
     return roundToScale(ret, scale);
 }
 
+/**
+ * Check whether an arbitrary precision Number can be converted to an STAmount
+ * of a given Asset without exceeding the asset's range.
+ *
+ * Use this before `roundToAsset` or `STAmount{asset, value}` on unchecked
+ * input, since those throw for out-of-range values, e.g. XRP above
+ * `STAmount::kMaxNativeN`.
+ *
+ * @param asset The relevant asset
+ * @param value The value to be checked
+ * @return true if the value is in range for the asset; false otherwise.
+ */
+[[nodiscard]] bool
+isRepresentable(Asset const& asset, Number const& value);
+
 //------------------------------------------------------------------------------
 
 inline bool

include/xrpl/protocol/STPathSet.h

@@ -2,6 +2,8 @@
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/basics/UnorderedContainers.h>
+#include <xrpl/basics/enum_bitops.h>
+#include <xrpl/beast/hash/hash_append.h>
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/json/json_value.h>
 #include <xrpl/protocol/AccountID.h>
@@ -15,37 +17,43 @@
 #include <cstdint>
 #include <memory>
 #include <optional>
+#include <type_traits>
 #include <utility>
 #include <vector>
 
 namespace xrpl {
 
+enum class STPathElementType : std::uint8_t {
+    // clang-format off
+
+    None     = 0x00,  ///< No element; also terminates the serialized path set.
+    Account  = 0x01,  ///< Rippling through an account (vs taking an offer).
+    Currency = 0x10,  ///< Currency follows.
+    Issuer   = 0x20,  ///< Issuer follows.
+    Mpt      = 0x40,  ///< MPT follows.
+    Boundary = 0xFF,  ///< Boundary between alternate paths.
+
+    Asset    = Currency | Mpt,                      ///< Either asset kind.
+    All      = Account | Currency | Issuer | Mpt,   ///< Every value-carrying bit.
+
+    // clang-format on
+};
+
+template <>
+struct enum_bitops::OptIn<STPathElementType> : std::true_type
+{
+};
+
 class STPathElement final : public CountedObject<STPathElement>
 {
-    unsigned int type_;
+    STPathElementType type_ = STPathElementType::None;
+    bool isOffer_ = true;
     AccountID accountID_;
     PathAsset assetID_;
     AccountID issuerID_;
 
-    bool isOffer_;
-    std::size_t hashValue_;
-
 public:
-    // Bitwise values (typeCurrency | typeMPT)
-    // NOLINTNEXTLINE(cppcoreguidelines-use-enum-class)
-    enum Type {
-        TypeNone = 0x00,
-        TypeAccount = 0x01,   // Rippling through an account (vs taking an offer).
-        TypeCurrency = 0x10,  // Currency follows.
-        TypeIssuer = 0x20,    // Issuer follows.
-        TypeMpt = 0x40,       // MPT follows.
-        TypeBoundary = 0xFF,  // Boundary between alternate paths.
-        TypeAsset = TypeCurrency | TypeMpt,
-        TypeAll = TypeAccount | TypeCurrency | TypeIssuer | TypeMpt,
-        // Combination of all types.
-    };
-
-    STPathElement();
+    STPathElement() = default;
     STPathElement(STPathElement const&) = default;
     STPathElement&
     operator=(STPathElement const&) = default;
@@ -62,42 +70,42 @@ public:
         bool forceAsset = false);
 
     STPathElement(
-        unsigned int uType,
+        STPathElementType type,
         AccountID const& account,
         PathAsset const& asset,
         AccountID const& issuer);
 
-    [[nodiscard]] std::uint32_t
-    getNodeType() const;
+    [[nodiscard]] STPathElementType
+    getNodeType() const noexcept;
 
     [[nodiscard]] bool
-    isOffer() const;
+    isOffer() const noexcept;
 
     [[nodiscard]] bool
-    isAccount() const;
+    isAccount() const noexcept;
 
     [[nodiscard]] bool
-    hasIssuer() const;
+    hasIssuer() const noexcept;
 
     [[nodiscard]] bool
-    hasCurrency() const;
+    hasCurrency() const noexcept;
 
     [[nodiscard]] bool
-    hasMPT() const;
+    hasMPT() const noexcept;
 
     [[nodiscard]] bool
-    hasAsset() const;
+    hasAsset() const noexcept;
 
     [[nodiscard]] bool
-    isNone() const;
+    isNone() const noexcept;
 
     // Nodes are either an account ID or a offer prefix. Offer prefixs denote a
     // class of offers.
     [[nodiscard]] AccountID const&
-    getAccountID() const;
+    getAccountID() const noexcept;
 
     [[nodiscard]] PathAsset const&
-    getPathAsset() const;
+    getPathAsset() const noexcept;
 
     [[nodiscard]] Currency const&
     getCurrency() const;
@@ -106,17 +114,18 @@ public:
     getMPTID() const;
 
     [[nodiscard]] AccountID const&
-    getIssuerID() const;
+    getIssuerID() const noexcept;
 
     [[nodiscard]] bool
-    isType(Type const& pe) const;
+    isType(STPathElementType pe) const noexcept;
 
-    bool
-    operator==(STPathElement const& t) const;
-
-private:
-    static std::size_t
-    getHash(STPathElement const& element);
+    friend bool
+    operator==(STPathElement const& lhs, STPathElement const& rhs) noexcept
+    {
+        return lhs.isType(STPathElementType::Account) == rhs.isType(STPathElementType::Account) &&
+            lhs.accountID_ == rhs.accountID_ && lhs.assetID_ == rhs.assetID_ &&
+            lhs.issuerID_ == rhs.issuerID_;
+    }
 };
 
 template <class Hasher>
@@ -124,7 +133,7 @@ void
 hash_append(Hasher& h, STPathElement const& e) noexcept
 {
     using beast::hash_append;
-    hash_append(h, (e.getNodeType() & STPathElement::TypeAccount) != 0u);
+    hash_append(h, e.isType(STPathElementType::Account));
     hash_append(h, e.getAccountID());
     hash_append(h, e.getPathAsset());
     hash_append(h, e.getIssuerID());
@@ -337,29 +346,16 @@ private:
 
 // ------------ STPathElement ------------
 
-inline STPathElement::STPathElement() : type_(TypeNone), isOffer_(true)
-{
-    // hashValue_ is derived from the whole object, so it is computed in the body
-    // once every other member is initialized (as in the other constructors).
-    // NOLINTNEXTLINE(cppcoreguidelines-prefer-member-initializer)
-    hashValue_ = getHash(*this);
-}
-
 inline STPathElement::STPathElement(
     std::optional<AccountID> const& account,
     std::optional<PathAsset> const& asset,
     std::optional<AccountID> const& issuer)
-    : type_(TypeNone)
 {
-    if (!account)
-    {
-        isOffer_ = true;
-    }
-    else
+    if (account)
     {
         isOffer_ = false;
         accountID_ = *account;
-        type_ |= TypeAccount;
+        type_ |= STPathElementType::Account;
         XRPL_ASSERT(
             accountID_ != noAccount(), "xrpl::STPathElement::STPathElement : account is set");
     }
@@ -367,17 +363,15 @@ inline STPathElement::STPathElement(
     if (asset)
     {
         assetID_ = *asset;
-        type_ |= assetID_.holds<Currency>() ? TypeCurrency : TypeMpt;
+        type_ |= assetID_.holds<Currency>() ? STPathElementType::Currency : STPathElementType::Mpt;
     }
 
     if (issuer)
     {
         issuerID_ = *issuer;
-        type_ |= TypeIssuer;
+        type_ |= STPathElementType::Issuer;
         XRPL_ASSERT(issuerID_ != noAccount(), "xrpl::STPathElement::STPathElement : issuer is set");
     }
-
-    hashValue_ = getHash(*this);
 }
 
 inline STPathElement::STPathElement(
@@ -385,108 +379,94 @@ inline STPathElement::STPathElement(
     PathAsset const& asset,
     AccountID const& issuer,
     bool forceAsset)
-    : type_(TypeNone)
-    , accountID_(account)
-    , assetID_(asset)
-    , issuerID_(issuer)
-    , isOffer_(isXRP(accountID_))
+    : isOffer_(isXRP(account)), accountID_(account), assetID_(asset), issuerID_(issuer)
 {
     if (!isOffer_)
-        type_ |= TypeAccount;
+        type_ |= STPathElementType::Account;
 
     if (forceAsset || !isXRP(assetID_))
-        type_ |= asset.holds<Currency>() ? TypeCurrency : TypeMpt;
+        type_ |= asset.holds<Currency>() ? STPathElementType::Currency : STPathElementType::Mpt;
 
     if (!isXRP(issuer))
-        type_ |= TypeIssuer;
-
-    hashValue_ = getHash(*this);
+        type_ |= STPathElementType::Issuer;
 }
 
 inline STPathElement::STPathElement(
-    unsigned int uType,
+    STPathElementType type,
     AccountID const& account,
     PathAsset const& asset,
     AccountID const& issuer)
-    : type_(uType)
-    , accountID_(account)
-    , assetID_(asset)
-    , issuerID_(issuer)
-    , isOffer_(isXRP(accountID_))
+    : type_(type), isOffer_(isXRP(account)), accountID_(account), assetID_(asset), issuerID_(issuer)
 {
     assetID_.visit(
-        [&](Currency const&) { type_ = type_ & (~Type::TypeMpt); },
-        [&](MPTID const&) { type_ = type_ & (~Type::TypeCurrency); });
-    // hashValue_ must be computed after type_ is adjusted above, so this cannot
-    // be a member initializer.
-    // NOLINTNEXTLINE(cppcoreguidelines-prefer-member-initializer)
-    hashValue_ = getHash(*this);
+        [&](Currency const&) { type_ &= ~STPathElementType::Mpt; },
+        [&](MPTID const&) { type_ &= ~STPathElementType::Currency; });
 }
 
-inline std::uint32_t
-STPathElement::getNodeType() const
+inline STPathElementType
+STPathElement::getNodeType() const noexcept
 {
     return type_;
 }
 
 inline bool
-STPathElement::isOffer() const
+STPathElement::isOffer() const noexcept
 {
     return isOffer_;
 }
 
 inline bool
-STPathElement::isAccount() const
+STPathElement::isAccount() const noexcept
 {
     return !isOffer();
 }
 
 inline bool
-STPathElement::isType(Type const& pe) const
+STPathElement::isType(STPathElementType pe) const noexcept
 {
-    return (type_ & pe) != 0u;
+    return (type_ & pe) != STPathElementType::None;
 }
 
 inline bool
-STPathElement::hasIssuer() const
+STPathElement::hasIssuer() const noexcept
 {
-    return isType(STPathElement::TypeIssuer);
+    return isType(STPathElementType::Issuer);
 }
 
 inline bool
-STPathElement::hasCurrency() const
+STPathElement::hasCurrency() const noexcept
 {
-    return isType(STPathElement::TypeCurrency);
+    return isType(STPathElementType::Currency);
 }
 
 inline bool
-STPathElement::hasMPT() const
+STPathElement::hasMPT() const noexcept
 {
-    return isType(STPathElement::TypeMpt);
+    return isType(STPathElementType::Mpt);
 }
 
 inline bool
-STPathElement::hasAsset() const
+STPathElement::hasAsset() const noexcept
 {
-    return isType(STPathElement::TypeAsset);
+    return isType(STPathElementType::Asset);
 }
 
 inline bool
-STPathElement::isNone() const
+STPathElement::isNone() const noexcept
 {
-    return getNodeType() == STPathElement::TypeNone;
+    return getNodeType() == STPathElementType::None;
 }
 
 // Nodes are either an account ID or a offer prefix. Offer prefixs denote a
 // class of offers.
 inline AccountID const&
-STPathElement::getAccountID() const
+STPathElement::getAccountID() const noexcept
 {
     return accountID_;
 }
 
 inline PathAsset const&
-STPathElement::getPathAsset() const
+STPathElement::getPathAsset() const noexcept
 {
     return assetID_;
 }
@@ -504,18 +484,11 @@ STPathElement::getMPTID() const
 }
 
 inline AccountID const&
-STPathElement::getIssuerID() const
+STPathElement::getIssuerID() const noexcept
 {
     return issuerID_;
 }
 
-inline bool
-STPathElement::operator==(STPathElement const& t) const
-{
-    return (type_ & TypeAccount) == (t.type_ & TypeAccount) && hashValue_ == t.hashValue_ &&
-        accountID_ == t.accountID_ && assetID_ == t.assetID_ && issuerID_ == t.issuerID_;
-}
-
 // ------------ STPath ------------
 
 inline STPath::STPath(std::vector<STPathElement> p) : path_(std::move(p))

include/xrpl/protocol/TER.h

@@ -133,7 +133,6 @@ enum TEMcodes : TERUnderlyingType {
     temBAD_MPT,
     temBAD_CIPHERTEXT,
     temINVALID_BYTECODE,
-    temTEMP_DISABLED,
 };
 
 //------------------------------------------------------------------------------
@@ -184,6 +183,8 @@ enum TEFcodes : TERUnderlyingType {
     tefBAD_PATH_COUNT,
     tefNO_BYTECODE,
     tefBYTECODE_NOT_INCLUDED,
+    tefTEMP_DISABLED,
+    tefEXCEEDS_LIMIT,
 };
 
 //------------------------------------------------------------------------------
@@ -231,6 +232,8 @@ enum TERcodes : TERUnderlyingType {
     terNO_DELEGATE_PERMISSION,  // Delegate does not have permission
     terLOCKED,                  // MPT is locked
     terNO_PERMISSION,           // No permission but retry
+    terTICKET_RESERVED,         // Ticket is reserved and cannot be consumed
+                                // until the reservation is released
 };
 
 //------------------------------------------------------------------------------

include/xrpl/protocol/XRPAmount.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <xrpl/basics/MathUtilities.h>
 #include <xrpl/basics/Number.h>
 #include <xrpl/basics/contract.h>
 #include <xrpl/beast/utility/Zero.h>
@@ -69,7 +70,13 @@ public:
     constexpr XRPAmount
     operator*(value_type const& rhs) const
     {
-        return XRPAmount{drops_ * rhs};
+        if (auto const result = checkedMul(drops_, rhs))
+            return XRPAmount{*result};
+        // Not reached in constant evaluation: an overflowing constant
+        // expression fails to compile instead.
+        XRPAmount product{*this};
+        product *= rhs;
+        return product;
     }
 
     friend constexpr XRPAmount
@@ -82,37 +89,23 @@ public:
     XRPAmount&
     operator+=(XRPAmount const& other)
     {
-        drops_ += other.drops();
-        return *this;
+        return *this += other.drops();
     }
 
     XRPAmount&
     operator-=(XRPAmount const& other)
     {
-        drops_ -= other.drops();
-        return *this;
+        return *this -= other.drops();
     }
 
     XRPAmount&
-    operator+=(value_type const& rhs)
-    {
-        drops_ += rhs;
-        return *this;
-    }
+    operator+=(value_type const& rhs);
 
     XRPAmount&
-    operator-=(value_type const& rhs)
-    {
-        drops_ -= rhs;
-        return *this;
-    }
+    operator-=(value_type const& rhs);
 
     XRPAmount&
-    operator*=(value_type const& rhs)
-    {
-        drops_ *= rhs;
-        return *this;
-    }
+    operator*=(value_type const& rhs);
 
     XRPAmount
     operator-() const

include/xrpl/protocol/detail/features.macro

@@ -17,6 +17,7 @@
 
 XRPL_FEATURE(Cosign,                      Supported::No,  VoteBehavior::DefaultNo)
 XRPL_FEATURE(SmartEscrow,                 Supported::No,  VoteBehavior::DefaultNo)
+// Requires LendingProtocolV1_1. New vaults take FixedPrecision plus cash-basis.
 XRPL_FEATURE(LendingProtocolV1_2,         Supported::No,  VoteBehavior::DefaultNo)
 XRPL_FIX    (Cleanup3_5_0,                Supported::Yes, VoteBehavior::DefaultNo)
 XRPL_FEATURE(ConfidentialMPTKeyRotation,  Supported::No,  VoteBehavior::DefaultNo)
@@ -60,7 +61,6 @@ XRPL_FIX    (InnerObjTemplate2,          Supported::Yes, VoteBehavior::DefaultNo
 XRPL_FIX    (EnforceNFTokenTrustline,    Supported::Yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (ReducedOffersV2,            Supported::Yes, VoteBehavior::DefaultNo)
 XRPL_FEATURE(NFTokenMintOffer,           Supported::Yes, VoteBehavior::DefaultNo)
-XRPL_FIX    (AMMv1_1,                    Supported::Yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (PreviousTxnID,              Supported::Yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (XChainRewardRounding,       Supported::Yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (EmptyDID,                   Supported::Yes, VoteBehavior::DefaultNo)
@@ -106,6 +106,7 @@ XRPL_RETIRE_FIX(1623)
 XRPL_RETIRE_FIX(1781)
 XRPL_RETIRE_FIX(AmendmentMajorityCalc)
 XRPL_RETIRE_FIX(AMMOverflowOffer)
+XRPL_RETIRE_FIX(AMMv1_1)
 XRPL_RETIRE_FIX(CheckThreading)
 XRPL_RETIRE_FIX(DisallowIncomingV1)
 XRPL_RETIRE_FIX(InnerObjTemplate)

include/xrpl/protocol/detail/ledger_entries.macro

@@ -417,6 +417,7 @@ LEDGER_ENTRY(ltMPTOKEN_ISSUANCE, 0x007e, MPTokenIssuance, mpt_issuance, ({
     {sfAuditorEncryptionKey,     SoeOptional},
     {sfIssuerKeyEpoch,           SoeOptional},
     {sfAuditorKeyEpoch,          SoeOptional},
+    {sfInitialIssuerEncryptionKey, SoeOptional},
     {sfConfidentialOutstandingAmount, SoeDefault},
 }))
 
@@ -438,6 +439,7 @@ LEDGER_ENTRY(ltMPTOKEN, 0x007f, MPToken, mptoken, ({
     {sfAuditorEncryptedBalance,     SoeOptional},
     {sfIssuerKeyMirrorEpoch,        SoeOptional},
     {sfAuditorKeyMirrorEpoch,       SoeOptional},
+    {sfIssuerMirrorEncryptionKey,   SoeOptional},
     {sfHolderEncryptionKey,         SoeOptional},
     {sfRecoveryKey,                 SoeOptional},
 }))
@@ -514,6 +516,8 @@ LEDGER_ENTRY(ltVAULT, 0x0084, Vault, vault, ({
     {sfAssetsAvailable,      SoeDefault},
     {sfAssetsMaximum,        SoeDefault},
     {sfLossUnrealized,       SoeDefault},
+    {sfYieldUnrealized,      SoeDefault},
+    {sfAssetsDeployed,       SoeDefault},
     {sfShareMPTID,           SoeRequired},
     {sfWithdrawalPolicy,     SoeRequired},
     {sfScale,                SoeDefault},

include/xrpl/protocol/detail/sfields.macro

@@ -240,6 +240,8 @@ TYPED_SFIELD(sfPrincipalRequested,       NUMBER,     14)
 TYPED_SFIELD(sfTotalValueOutstanding,    NUMBER,     15, SField::kSmdNeedsAsset | SField::kSmdDefault)
 TYPED_SFIELD(sfPeriodicPayment,          NUMBER,     16)
 TYPED_SFIELD(sfManagementFeeOutstanding, NUMBER,     17, SField::kSmdNeedsAsset | SField::kSmdDefault)
+TYPED_SFIELD(sfYieldUnrealized,          NUMBER,     18, SField::kSmdNeedsAsset | SField::kSmdDefault)
+TYPED_SFIELD(sfAssetsDeployed,           NUMBER,     19, SField::kSmdNeedsAsset | SField::kSmdDefault)
 
 // 32-bit signed (common)
 TYPED_SFIELD(sfLoanScale,                INT32,      1)
@@ -331,6 +333,8 @@ TYPED_SFIELD(sfAmountCommitment,            VL,     45)
 TYPED_SFIELD(sfBalanceCommitment,           VL,     46)
 TYPED_SFIELD(sfBytecode,                    VL,     47)
 TYPED_SFIELD(sfRecoveryKey,                 VL,     48)
+TYPED_SFIELD(sfInitialIssuerEncryptionKey,  VL,     49)
+TYPED_SFIELD(sfIssuerMirrorEncryptionKey,   VL,     50)
 
 // account (common)
 TYPED_SFIELD(sfAccount,                  ACCOUNT,    1)

include/xrpl/protocol/detail/transactions.macro

@@ -1175,6 +1175,20 @@ TRANSACTION(ttTRANSACTION_PROPOSAL_CREATE, 95, TransactionProposalCreate,
     {sfExpiration, SoeRequired},
 }))
 
+// ttTRANSACTION_PROPOSAL_SIGN arrives in a later PR and takes the next unassigned type.
+
+/** This transaction deletes a TransactionProposal, releasing its owner's
+    reserve. While the proposal is live only its Owner or its target account
+    may cancel; once it is terminal anyone may (On-Chain Cosigner spec §7). */
+#if TRANSACTION_INCLUDE
+#   include <xrpl/tx/transactors/proposal/TransactionProposalCancel.h>
+#endif
+TRANSACTION(ttTRANSACTION_PROPOSAL_CANCEL, 94, TransactionProposalCancel,
+    ({.amendment = featureCosign}),
+    ({
+    {sfProposalID, SoeRequired},
+}))
+
 /** This system-generated transaction type is used to update the status of the various amendments.
 
     For details, see: https://xrpl.org/amendments.html

include/xrpl/protocol/jss.h

@@ -252,6 +252,9 @@ JSS(expected_date);                  // out: any (warnings)
 JSS(expected_date_UTC);              // out: any (warnings)
 JSS(expected_ledger_size);           // out: TxQ
 JSS(expiration);                     // out: AccountOffers, AccountChannels, ValidatorList, amm_info
+JSS(gas_limit);                      // out: NetworkOPs
+JSS(bytecode_size_limit);            // out: NetworkOPs
+JSS(gas_price);                      // out: NetworkOPs
 JSS(fail_hard);                      // in: Sign, Submit
 JSS(failed);                         // out: InboundLedger
 JSS(feature);                        // in: Feature
@@ -559,7 +562,7 @@ JSS(signing_key);                 // out: NetworkOPs
 JSS(signing_keys);                // out: ValidatorList
 JSS(signing_time);                // out: NetworkOPs
 JSS(signer_lists);                // in/out: AccountInfo
-JSS(size);                        // out: get_aggregate_price, ServerHandler
+JSS(size);                        // out: get_aggregate_price
 JSS(snapshot);                    // in: Subscribe
 JSS(source_account);              // in: PathRequest, RipplePathFind
 JSS(source_amount);               // in: PathRequest, RipplePathFind

include/xrpl/protocol_autogen/ledger_entries/MPToken.h

@@ -316,6 +316,30 @@ public:
         return this->sle_->isFieldPresent(sfAuditorKeyMirrorEpoch);
     }
 
+    /**
+     * @brief Get sfIssuerMirrorEncryptionKey (SoeOptional)
+     * @return The field value, or std::nullopt if not present.
+     */
+    [[nodiscard]]
+    protocol_autogen::Optional<SF_VL::type::value_type>
+    getIssuerMirrorEncryptionKey() const
+    {
+        if (hasIssuerMirrorEncryptionKey())
+            return this->sle_->at(sfIssuerMirrorEncryptionKey);
+        return std::nullopt;
+    }
+
+    /**
+     * @brief Check if sfIssuerMirrorEncryptionKey is present.
+     * @return True if the field is present, false otherwise.
+     */
+    [[nodiscard]]
+    bool
+    hasIssuerMirrorEncryptionKey() const
+    {
+        return this->sle_->isFieldPresent(sfIssuerMirrorEncryptionKey);
+    }
+
     /**
      * @brief Get sfHolderEncryptionKey (SoeOptional)
      * @return The field value, or std::nullopt if not present.
@@ -565,6 +589,17 @@ public:
         return *this;
     }
 
+    /**
+     * @brief Set sfIssuerMirrorEncryptionKey (SoeOptional)
+     * @return Reference to this builder for method chaining.
+     */
+    MPTokenBuilder&
+    setIssuerMirrorEncryptionKey(std::decay_t<typename SF_VL::type::value_type> const& value)
+    {
+        object_[sfIssuerMirrorEncryptionKey] = value;
+        return *this;
+    }
+
     /**
      * @brief Set sfHolderEncryptionKey (SoeOptional)
      * @return Reference to this builder for method chaining.

include/xrpl/protocol_autogen/ledger_entries/MPTokenIssuance.h

@@ -399,6 +399,30 @@ public:
         return this->sle_->isFieldPresent(sfAuditorKeyEpoch);
     }
 
+    /**
+     * @brief Get sfInitialIssuerEncryptionKey (SoeOptional)
+     * @return The field value, or std::nullopt if not present.
+     */
+    [[nodiscard]]
+    protocol_autogen::Optional<SF_VL::type::value_type>
+    getInitialIssuerEncryptionKey() const
+    {
+        if (hasInitialIssuerEncryptionKey())
+            return this->sle_->at(sfInitialIssuerEncryptionKey);
+        return std::nullopt;
+    }
+
+    /**
+     * @brief Check if sfInitialIssuerEncryptionKey is present.
+     * @return True if the field is present, false otherwise.
+     */
+    [[nodiscard]]
+    bool
+    hasInitialIssuerEncryptionKey() const
+    {
+        return this->sle_->isFieldPresent(sfInitialIssuerEncryptionKey);
+    }
+
     /**
      * @brief Get sfConfidentialOutstandingAmount (SoeDefault)
      * @return The field value, or std::nullopt if not present.
@@ -670,6 +694,17 @@ public:
         return *this;
     }
 
+    /**
+     * @brief Set sfInitialIssuerEncryptionKey (SoeOptional)
+     * @return Reference to this builder for method chaining.
+     */
+    MPTokenIssuanceBuilder&
+    setInitialIssuerEncryptionKey(std::decay_t<typename SF_VL::type::value_type> const& value)
+    {
+        object_[sfInitialIssuerEncryptionKey] = value;
+        return *this;
+    }
+
     /**
      * @brief Set sfConfidentialOutstandingAmount (SoeDefault)
      * @return Reference to this builder for method chaining.

include/xrpl/protocol_autogen/ledger_entries/Vault.h

@@ -242,6 +242,54 @@ public:
         return this->sle_->isFieldPresent(sfLossUnrealized);
     }
 
+    /**
+     * @brief Get sfYieldUnrealized (SoeDefault)
+     * @return The field value, or std::nullopt if not present.
+     */
+    [[nodiscard]]
+    protocol_autogen::Optional<SF_NUMBER::type::value_type>
+    getYieldUnrealized() const
+    {
+        if (hasYieldUnrealized())
+            return this->sle_->at(sfYieldUnrealized);
+        return std::nullopt;
+    }
+
+    /**
+     * @brief Check if sfYieldUnrealized is present.
+     * @return True if the field is present, false otherwise.
+     */
+    [[nodiscard]]
+    bool
+    hasYieldUnrealized() const
+    {
+        return this->sle_->isFieldPresent(sfYieldUnrealized);
+    }
+
+    /**
+     * @brief Get sfAssetsDeployed (SoeDefault)
+     * @return The field value, or std::nullopt if not present.
+     */
+    [[nodiscard]]
+    protocol_autogen::Optional<SF_NUMBER::type::value_type>
+    getAssetsDeployed() const
+    {
+        if (hasAssetsDeployed())
+            return this->sle_->at(sfAssetsDeployed);
+        return std::nullopt;
+    }
+
+    /**
+     * @brief Check if sfAssetsDeployed is present.
+     * @return True if the field is present, false otherwise.
+     */
+    [[nodiscard]]
+    bool
+    hasAssetsDeployed() const
+    {
+        return this->sle_->isFieldPresent(sfAssetsDeployed);
+    }
+
     /**
      * @brief Get sfShareMPTID (SoeRequired)
      * @return The field value.
@@ -571,6 +619,28 @@ public:
         return *this;
     }
 
+    /**
+     * @brief Set sfYieldUnrealized (SoeDefault)
+     * @return Reference to this builder for method chaining.
+     */
+    VaultBuilder&
+    setYieldUnrealized(std::decay_t<typename SF_NUMBER::type::value_type> const& value)
+    {
+        object_[sfYieldUnrealized] = value;
+        return *this;
+    }
+
+    /**
+     * @brief Set sfAssetsDeployed (SoeDefault)
+     * @return Reference to this builder for method chaining.
+     */
+    VaultBuilder&
+    setAssetsDeployed(std::decay_t<typename SF_NUMBER::type::value_type> const& value)
+    {
+        object_[sfAssetsDeployed] = value;
+        return *this;
+    }
+
     /**
      * @brief Set sfShareMPTID (SoeRequired)
      * @return Reference to this builder for method chaining.

include/xrpl/protocol_autogen/transactions/TransactionProposalCancel.h

@@ -0,0 +1,131 @@
+// This file is auto-generated. Do not edit.
+#pragma once
+
+#include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/STParsedJSON.h>
+#include <xrpl/protocol/jss.h>
+#include <xrpl/protocol_autogen/TransactionBase.h>
+#include <xrpl/protocol_autogen/TransactionBuilderBase.h>
+#include <xrpl/json/json_value.h>
+
+#include <stdexcept>
+#include <optional>
+
+namespace xrpl::transactions {
+
+class TransactionProposalCancelBuilder;
+
+/**
+ * @brief Transaction: TransactionProposalCancel
+ *
+ * Type: ttTRANSACTION_PROPOSAL_CANCEL (94)
+ * Delegable: Delegation::NotDelegable
+ * Amendment: featureCosign
+ * Privileges: Privilege::NoPriv
+ *
+ * Immutable wrapper around STTx providing type-safe field access.
+ * Use TransactionProposalCancelBuilder to construct new transactions.
+ */
+class TransactionProposalCancel : public TransactionBase
+{
+public:
+    static constexpr xrpl::TxType txType = ttTRANSACTION_PROPOSAL_CANCEL;
+
+    /**
+     * @brief Construct a TransactionProposalCancel transaction wrapper from an existing STTx object.
+     * @throws std::runtime_error if the transaction type doesn't match.
+     */
+    explicit TransactionProposalCancel(std::shared_ptr<STTx const> tx)
+        : TransactionBase(std::move(tx))
+    {
+        // Verify transaction type
+        if (tx_->getTxnType() != txType)
+        {
+            throw std::runtime_error("Invalid transaction type for TransactionProposalCancel");
+        }
+    }
+
+    // Transaction-specific field getters
+
+    /**
+     * @brief Get sfProposalID (SoeRequired)
+     * @return The field value.
+     */
+    [[nodiscard]]
+    SF_UINT256::type::value_type
+    getProposalID() const
+    {
+        return this->tx_->at(sfProposalID);
+    }
+};
+
+/**
+ * @brief Builder for TransactionProposalCancel transactions.
+ *
+ * Provides a fluent interface for constructing transactions with method chaining.
+ * Uses STObject internally for flexible transaction construction.
+ * Inherits common field setters from TransactionBuilderBase.
+ */
+class TransactionProposalCancelBuilder : public TransactionBuilderBase<TransactionProposalCancelBuilder>
+{
+public:
+    /**
+     * @brief Construct a new TransactionProposalCancelBuilder with required fields.
+     * @param account The account initiating the transaction.
+     * @param proposalID The sfProposalID field value.
+     * @param sequence Optional sequence number for the transaction.
+     * @param fee Optional fee for the transaction.
+     */
+    TransactionProposalCancelBuilder(SF_ACCOUNT::type::value_type account,
+                     std::decay_t<typename SF_UINT256::type::value_type> const& proposalID,                    std::optional<SF_UINT32::type::value_type> sequence = std::nullopt,
+                    std::optional<SF_AMOUNT::type::value_type> fee = std::nullopt
+)
+        : TransactionBuilderBase<TransactionProposalCancelBuilder>(ttTRANSACTION_PROPOSAL_CANCEL, account, sequence, fee)
+    {
+        setProposalID(proposalID);
+    }
+
+    /**
+     * @brief Construct a TransactionProposalCancelBuilder from an existing STTx object.
+     * @param tx The existing transaction to copy from.
+     * @throws std::runtime_error if the transaction type doesn't match.
+     */
+    TransactionProposalCancelBuilder(std::shared_ptr<STTx const> tx)
+    {
+        if (tx->getTxnType() != ttTRANSACTION_PROPOSAL_CANCEL)
+        {
+            throw std::runtime_error("Invalid transaction type for TransactionProposalCancelBuilder");
+        }
+        object_ = *tx;
+    }
+
+    /**
+     * @brief Transaction-specific field setters
+     */
+
+    /**
+     * @brief Set sfProposalID (SoeRequired)
+     * @return Reference to this builder for method chaining.
+     */
+    TransactionProposalCancelBuilder&
+    setProposalID(std::decay_t<typename SF_UINT256::type::value_type> const& value)
+    {
+        object_[sfProposalID] = value;
+        return *this;
+    }
+
+    /**
+     * @brief Build and return the TransactionProposalCancel wrapper.
+     * @param publicKey The public key for signing.
+     * @param secretKey The secret key for signing.
+     * @return The constructed transaction wrapper.
+     */
+    TransactionProposalCancel
+    build(PublicKey const& publicKey, SecretKey const& secretKey)
+    {
+        sign(publicKey, secretKey);
+        return TransactionProposalCancel{std::make_shared<STTx>(std::move(object_))};
+    }
+};
+
+}  // namespace xrpl::transactions

include/xrpl/server/detail/JSONRPCUtil.h

@@ -7,18 +7,6 @@
 
 namespace xrpl {
 
-/**
- * Writes an HTTP reply carrying @p strMsg with status @p nStatus to @p output,
- * and logs the status at trace. The body is not logged here: it may carry a
- * credential this library cannot mask, so the caller logs it masked.
- *
- * A 401 with an empty body is answered with the fixed authentication page.
- *
- * @param nStatus The HTTP status code.
- * @param strMsg The body.
- * @param output Where the reply bytes are written.
- * @param j The journal the status is logged to.
- */
 void
 httpReply(int nStatus, std::string const& strMsg, json::Output const&, beast::Journal j);
 

include/xrpl/shamap/SHAMap.h

@@ -2,6 +2,7 @@
 
 #include <xrpl/basics/Blob.h>
 #include <xrpl/basics/IntrusivePointer.h>
+#include <xrpl/basics/Log.h>
 #include <xrpl/basics/SHAMapHash.h>
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -17,6 +18,7 @@
 #include <xrpl/shamap/SHAMapNodeID.h>
 #include <xrpl/shamap/SHAMapTreeNode.h>
 
+#include <atomic>
 #include <condition_variable>
 #include <cstddef>
 #include <cstdint>
@@ -40,7 +42,7 @@ class SHAMapSyncFilter;
 /**
  * Describes the current state of a given SHAMap
  */
-enum class SHAMapState {
+enum class SHAMapState : std::uint8_t {
     /**
      * The map is in flux and objects can be added and removed.
      *
@@ -120,16 +122,42 @@ private:
      */
     std::uint32_t cowid_ = 1;
 
+    // ledgerSeq_, state_ and full_ are touched on the nodestore fetch path and on a
+    // getMissingNodes() walk, neither of which may block, so pin them lock-free.
+    static_assert(std::atomic<std::uint32_t>::is_always_lock_free);
+    static_assert(std::atomic<SHAMapState>::is_always_lock_free);
+    static_assert(std::atomic<bool>::is_always_lock_free);
+
     /**
      * The sequence of the ledger that this map references, if any.
+     *
+     * Written when a map's ledger sequence is established (Ledger::setFull(),
+     * InboundLedger) while a nodestore reader thread reads it. Relaxed either
+     * way: it serves as a lookup hint for a nodestore keyed by hash.
      */
-    std::uint32_t ledgerSeq_ = 0;
+    std::atomic<std::uint32_t> ledgerSeq_ = 0;
 
     SHAMapTreeNodePtr root_;
-    mutable SHAMapState state_;
+
+    /**
+     * The map's state.
+     *
+     * A getMissingNodes() walk writes it, through setInvalid() and
+     * clearSynching(), while whatever drives the acquisition reads it.
+     * The walk runs with the acquisition's lock released, so this is atomic
+     * rather than guarded.
+     */
+    mutable std::atomic<SHAMapState> state_;
     SHAMapType const type_;
-    bool backed_ = true;         // Map is backed by the database
-    mutable bool full_ = false;  // Map is believed complete in database
+    bool backed_ = true;  // Map is backed by the database
+
+    /**
+     * Map is believed complete in database.
+     *
+     * Atomic because finishFetch() clears it on any nodestore reader thread,
+     * several of which can run at once.
+     */
+    mutable std::atomic<bool> full_ = false;
 
 public:
     /**
@@ -152,7 +180,14 @@ public:
     SHAMap&
     operator=(SHAMap const&) = delete;
 
-    // Take a snapshot of the given map:
+    /**
+     * Take a snapshot of the given map.
+     *
+     * @param other The map to snapshot. An Invalid source yields an Invalid
+     *        snapshot.
+     * @param isMutable Whether the snapshot may be modified. Ignored when other
+     *        is Invalid.
+     */
     SHAMap(SHAMap const& other, bool isMutable);
 
     // build new map
@@ -190,17 +225,33 @@ public:
 
     //--------------------------------------------------------------------------
 
-    // Returns a new map that's a snapshot of this one.
-    // Handles copy on write for mutable snapshots.
+    /**
+     * Return a new map that is a snapshot of this one.
+     *
+     * Handles copy on write for mutable snapshots. An invalid map yields an
+     * invalid snapshot.
+     *
+     * @param isMutable Whether the snapshot may be modified.
+     * @return The snapshot.
+     */
     std::shared_ptr<SHAMap>
     snapShot(bool isMutable) const;
 
-    /*  Mark this SHAMap as "should be full", indicating
-        that the local server wants all the corresponding nodes
-        in durable storage.
-    */
+    /**
+     * Mark this map as "should be full": the local server wants every node
+     * it references in durable storage, so a nodestore miss is a gap to report.
+     *
+     * Publishes the ledger sequence before the flag. The sequence store is
+     * relaxed and the flag store is release, and finishFetch() reads the
+     * sequence only after acquiring the flag, so the one miss that withdraws
+     * the flag always reports the sequence stored here. Keeping both stores in
+     * one place is what makes that order impossible to get wrong.
+     *
+     * @param ledgerSeq Sequence of the ledger this map belongs to, which the
+     *        gap report names.
+     */
     void
-    setFull();
+    setFull(std::uint32_t ledgerSeq);
 
     void
     setLedgerSeq(std::uint32_t lseq);
@@ -296,9 +347,13 @@ public:
      * concurrency, to discover nodes referenced in the
      * SHAMap but not available locally.
      *
+     * Only a leaf may occupy a position at or beyond kLeafDepth. A map that
+     * breaks that is marked Invalid and the traversal is abandoned, so callers
+     * ask isValid() to tell an empty result from a satisfied map.
+     *
      * @param maxNodes The maximum number of found nodes to return
      * @param filter The filter to use when retrieving nodes
-     * @param return The nodes known to be missing
+     * @return The nodes known to be missing, or empty if the map is Invalid
      */
     std::vector<std::pair<SHAMapNodeID, UInt256>>
     getMissingNodes(int maxNodes, SHAMapSyncFilter const* filter);
@@ -341,6 +396,9 @@ public:
      * This function is used when receiving the root node of a SHAMap from a peer during ledger
      * synchronization. The node must already have been deserialized.
      *
+     * A root offered under a hash the map does not hold names another tree and
+     * is reported as invalid data. A root matching that hash is a duplicate.
+     *
      * @param hash The expected hash of the root node.
      * @param rootNode A deserialized root node to add.
      * @param filter Optional sync filter to track received nodes.
@@ -360,6 +418,10 @@ public:
      * is inserted at the position specified by nodeID. The node must already have been
      * deserialized.
      *
+     * A node that no valid tree can hold makes the map Invalid, which is
+     * terminal: the root hash committed to an impossible shape, so no peer
+     * can satisfy it.
+     *
      * @param nodeID The position in the tree where this node belongs.
      * @param treeNode A deserialized tree node to add.
      * @param filter Optional sync filter to track received nodes.
@@ -375,16 +437,57 @@ public:
         SHAMapTreeNodePtr treeNode,
         SHAMapSyncFilter const* filter);
 
-    // status functions
-    void
+    /**
+     * Mark this map as immutable, so it can no longer be modified.
+     *
+     * @return false if the map is Invalid and was left unchanged, true
+     *         otherwise.
+     */
+    [[nodiscard]] bool
     setImmutable();
-    bool
+
+    /**
+     * @return Whether the map is being synced against a hash it was given, so
+     *         its hash is fixed while nodes may still be added.
+     */
+    [[nodiscard]] bool
     isSynching() const;
+
+    /**
+     * @return Whether the map is settled, with its hash and nodes fixed.
+     */
+    [[nodiscard]] bool
+    isImmutable() const;
+
+    /**
+     * Mark this map as syncing, fixing its hash while still allowing missing
+     * nodes to be added.
+     *
+     * The map must be freshly constructed. The body asserts that the map is not
+     * Invalid, so a caller that ignores the precondition stops a build with
+     * assertions enabled.
+     */
     void
     setSynching();
+
+    /**
+     * Mark this map as no longer syncing, so it can be modified again.
+     *
+     * Moves only a Synching map. An Immutable map stays settled, a Modifying
+     * map has nothing to clear, and Invalid is terminal.
+     */
     void
     clearSynching();
-    bool
+
+    /**
+     * Whether the map can still be the map it claims to be.
+     *
+     * A map that is merely missing nodes is valid, and stays valid until
+     * something proves the tree it is syncing against cannot exist.
+     *
+     * @return Whether the map has not been proven impossible.
+     */
+    [[nodiscard]] bool
     isValid() const;
 
     // caution: otherMap must be accessed only by this function
@@ -524,6 +627,51 @@ private:
     using DeltaRef =
         std::pair<boost::intrusive_ptr<SHAMapItem const>, boost::intrusive_ptr<SHAMapItem const>>;
 
+    /**
+     * The sequence of the ledger this map references, read atomically.
+     *
+     * @return The sequence, or zero if the map references no ledger.
+     */
+    [[nodiscard]] std::uint32_t
+    ledgerSeq() const;
+
+    /**
+     * The current state, read atomically.
+     *
+     * Orders state_ alone. The tree's nodes carry no ordering guarantees.
+     *
+     * @return The state as of the call, which a concurrent walk may already
+     *         have moved past.
+     */
+    [[nodiscard]] SHAMapState
+    state() const;
+
+    /**
+     * Record that the map is provably not the one it claims to be.
+     *
+     * Private because only the map itself can prove that, from a node that
+     * contradicts the hashes it is syncing against. Cannot fail, since
+     * Invalid outranks every other state; see trySetState().
+     */
+    void
+    setInvalid();
+
+    /**
+     * Move the map to a new state, atomically.
+     *
+     * With clearSynching(), the only writer of state_ past construction, so
+     * the order between the states lives in one place: Invalid outranks all
+     * of them and is always stored, while every other transition is refused
+     * once the map is Invalid, which is what makes that verdict terminal.
+     * clearSynching() is narrower and moves only Synching.
+     *
+     * @param desired The state to move to.
+     * @return false if the map is Invalid and the requested state is not,
+     *         leaving it unchanged; true otherwise.
+     */
+    bool
+    trySetState(SHAMapState desired);
+
     // tree node cache operations
     SHAMapTreeNodePtr
     cacheLookup(SHAMapHash const& hash) const;
@@ -739,46 +887,120 @@ private:
 };
 
 inline void
-SHAMap::setFull()
+SHAMap::setFull(std::uint32_t ledgerSeq)
 {
-    full_ = true;
+    ledgerSeq_.store(ledgerSeq, std::memory_order_relaxed);
+    full_.store(true, std::memory_order_release);
 }
 
 inline void
 SHAMap::setLedgerSeq(std::uint32_t lseq)
 {
-    ledgerSeq_ = lseq;
+    ledgerSeq_.store(lseq, std::memory_order_relaxed);
 }
 
-inline void
+inline std::uint32_t
+SHAMap::ledgerSeq() const
+{
+    return ledgerSeq_.load(std::memory_order_relaxed);
+}
+
+inline SHAMapState
+SHAMap::state() const
+{
+    return state_.load(std::memory_order_acquire);
+}
+
+inline bool
+SHAMap::trySetState(SHAMapState desired)
+{
+    // Invalid is stored outright: a walk reaching that verdict has to win against a thread
+    // settling the map.
+    if (desired == SHAMapState::Invalid)
+    {
+        state_.store(SHAMapState::Invalid, std::memory_order_release);
+        return true;
+    }
+
+    // A failed exchange both reports the state and refreshes expected, so no load is needed
+    // ahead of the loop.
+    auto expected = SHAMapState::Modifying;
+    while (expected != SHAMapState::Invalid)
+    {
+        if (state_.compare_exchange_weak(
+                expected, desired, std::memory_order_acq_rel, std::memory_order_acquire))
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
+inline bool
 SHAMap::setImmutable()
 {
-    XRPL_ASSERT(state_ != SHAMapState::Invalid, "xrpl::SHAMap::setImmutable : state is valid");
-    state_ = SHAMapState::Immutable;
+    SOMETIMES(!isValid(), "xrpl::SHAMap::setImmutable : map is invalid");
+    return trySetState(SHAMapState::Immutable);
 }
 
 inline bool
 SHAMap::isSynching() const
 {
-    return state_ == SHAMapState::Synching;
+    return state() == SHAMapState::Synching;
+}
+
+inline bool
+SHAMap::isImmutable() const
+{
+    return state() == SHAMapState::Immutable;
 }
 
 inline void
 SHAMap::setSynching()
 {
-    state_ = SHAMapState::Synching;
+    // Guarded, so this is not a way out of Invalid.
+    if (!trySetState(SHAMapState::Synching))
+    {
+        // Only ever called on a freshly constructed map.
+        // LCOV_EXCL_START
+        UNREACHABLE("xrpl::SHAMap::setSynching : map is invalid");
+        // LCOV_EXCL_STOP
+    }
 }
 
 inline void
 SHAMap::clearSynching()
 {
-    state_ = SHAMapState::Modifying;
+    // Only Synching moves. A walk can end after the ledger settled, and then the map stays
+    // Immutable; a Modifying map has nothing to clear; an invalid map stays invalid. Only that
+    // last refusal is logged, since a concurrent walk is what produces it.
+    auto expected = SHAMapState::Synching;
+    if (state_.compare_exchange_strong(
+            expected, SHAMapState::Modifying, std::memory_order_acq_rel, std::memory_order_acquire))
+    {
+        return;
+    }
+
+    bool const invalid = expected == SHAMapState::Invalid;
+    SOMETIMES(invalid, "xrpl::SHAMap::clearSynching : map is invalid");
+    if (invalid)
+    {
+        JLOG(journal_.warn()) << "Refused to clear synching on an invalid map, root hash "
+                              << root_->getHash();
+    }
 }
 
 inline bool
 SHAMap::isValid() const
 {
-    return state_ != SHAMapState::Invalid;
+    return state() != SHAMapState::Invalid;
+}
+
+inline void
+SHAMap::setInvalid()
+{
+    // Through trySetState() like every other transition, so state_ has one writer funnel.
+    trySetState(SHAMapState::Invalid);
 }
 
 inline void

include/xrpl/shamap/SHAMapInnerNode.h

@@ -31,7 +31,19 @@ private:
      */
     TaggedPointer hashesAndChildren_;
 
-    std::uint32_t fullBelowGen_ = 0;
+    // Pin that wrapping fullBelowGen_ in an atomic keeps the packed layout, and that the load
+    // isFullBelow() does once per node of every walk stays lock-free.
+    static_assert(std::atomic<std::uint32_t>::is_always_lock_free);
+    static_assert(sizeof(std::atomic<std::uint32_t>) == sizeof(std::uint32_t));
+    static_assert(alignof(std::atomic<std::uint32_t>) == alignof(std::uint32_t));
+
+    /**
+     * Written from more than one thread, since canonicalization shares a node
+     * between maps and a walk can run with the acquisition lock released (see
+     * SHAMap::state_). Relaxed both ways, since a generation is only compared
+     * for equality and the children it vouches for are published through lock_.
+     */
+    std::atomic<std::uint32_t> fullBelowGen_ = 0;
     std::uint16_t isBranch_ = 0;
 
     /**
@@ -204,13 +216,13 @@ SHAMapInnerNode::getBranchCount() const
 inline bool
 SHAMapInnerNode::isFullBelow(std::uint32_t generation) const
 {
-    return fullBelowGen_ == generation;
+    return fullBelowGen_.load(std::memory_order_relaxed) == generation;
 }
 
 inline void
 SHAMapInnerNode::setFullBelowGen(std::uint32_t gen)
 {
-    fullBelowGen_ = gen;
+    fullBelowGen_.store(gen, std::memory_order_relaxed);
 }
 
 }  // namespace xrpl

include/xrpl/tx/ApplyContext.h

@@ -51,7 +51,8 @@ public:
         beast::Journal journal = beast::Journal{beast::Journal::getNullSink()})
         : ApplyContext(registry, base, std::nullopt, tx, preclaimResult, baseFee, flags, journal)
     {
-        XRPL_ASSERT((flags & TapBatch) == 0, "Batch apply flag should not be set");
+        XRPL_ASSERT(
+            (flags & ApplyFlags::Batch) == ApplyFlags::None, "Batch apply flag should not be set");
     }
 
     std::reference_wrapper<ServiceRegistry> registry;

include/xrpl/tx/Transactor.h

@@ -59,10 +59,11 @@ public:
         , parentBatchId(parentBatchId)
         , j(j)
     {
-        XRPL_ASSERT((flags & TapBatch) == TapBatch, "Batch apply flag should be set");
+        XRPL_ASSERT(
+            (flags & ApplyFlags::Batch) == ApplyFlags::Batch, "Batch apply flag should be set");
         XRPL_ASSERT_IF(
-            (flags & TapProposal) != TapNone,
-            (flags & TapDryRun) != TapNone,
+            (flags & ApplyFlags::Proposal) != ApplyFlags::None,
+            (flags & ApplyFlags::DryRun) != ApplyFlags::None,
             "xrpl::PreflightContext : proposal preflight implies dry run");
     }
 
@@ -74,10 +75,11 @@ public:
         beast::Journal j = beast::Journal{beast::Journal::getNullSink()})
         : registry(registry), tx(tx), rules(std::move(rules)), flags(flags), j(j)
     {
-        XRPL_ASSERT((flags & TapBatch) == 0, "Batch apply flag should not be set");
+        XRPL_ASSERT(
+            (flags & ApplyFlags::Batch) == ApplyFlags::None, "Batch apply flag should not be set");
         XRPL_ASSERT_IF(
-            (flags & TapProposal) != TapNone,
-            (flags & TapDryRun) != TapNone,
+            (flags & ApplyFlags::Proposal) != ApplyFlags::None,
+            (flags & ApplyFlags::DryRun) != ApplyFlags::None,
             "xrpl::PreflightContext : proposal preflight implies dry run");
     }
 
@@ -116,7 +118,7 @@ public:
         , j(j)
     {
         XRPL_ASSERT(
-            parentBatchId.has_value() == ((flags & TapBatch) == TapBatch),
+            parentBatchId.has_value() == ((flags & ApplyFlags::Batch) == ApplyFlags::Batch),
             "Parent Batch ID should be set if batch apply flag is set");
     }
 
@@ -129,7 +131,8 @@ public:
         beast::Journal j = beast::Journal{beast::Journal::getNullSink()})
         : PreclaimContext(registry, view, preflightResult, tx, flags, std::nullopt, j)
     {
-        XRPL_ASSERT((flags & TapBatch) == 0, "Batch apply flag should not be set");
+        XRPL_ASSERT(
+            (flags & ApplyFlags::Batch) == ApplyFlags::None, "Batch apply flag should not be set");
     }
 
     PreclaimContext&
@@ -375,6 +378,22 @@ public:
     /////////////////////////////////////////////////////
 
     // Interface used by AccountDelete
+    /**
+     * This method removes one Ticket ledger-object from the ledger. AccountDelete uses it to
+     * clean up Ticket objects en masse.
+     *
+     * This method reduces the TicketCount and the OwnerCount of the Owner AccountRoot object. If
+     * a TransactionProposal reserved this Ticket, that proposal is deleted as well: once the
+     * Ticket is gone, its proposed transaction can never be applied (tefNO_TICKET).
+     *
+     * @param view         the apply view for making changes.
+     * @param account      the account which owns the Ticket object.
+     * @param ticketIndex  ticketIndex is used to construct the ledger-entry ID of Ticket object.
+     * @param j            the journal reference used to log messages.
+     *
+     * @return the final TER after all invariant checks. `tefBAD_LEDGER` is returned if Ticket,
+     * Owner AccountRoot is not found in the apply-view ledger.
+     */
     static TER
     ticketDelete(
         ApplyView& view,

include/xrpl/tx/applySteps.h

@@ -41,7 +41,7 @@ struct ApplyResult
 inline bool
 isTecClaimHardFail(TER ter, ApplyFlags flags)
 {
-    return isTecClaim(ter) && ((flags & TapRetry) == 0u);
+    return isTecClaim(ter) && ((flags & ApplyFlags::Retry) == ApplyFlags::None);
 }
 
 /**

include/xrpl/tx/invariants/CosignerInvariant.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/protocol/Keylet.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/TER.h>
+#include <xrpl/protocol/XRPAmount.h>
+
+#include <cstdint>
+#include <set>
+#include <vector>
+
+namespace xrpl {
+
+class ReadView;
+
+/**
+ * @brief Invariants for TransactionProposal ledger entries.
+ *
+ * - Only transaction types implementing proposal lifecycle operations may
+ *   create or modify proposals, and a failed one leaves no proposal effect.
+ * - A proposal is deleted only by TransactionProposalCancel or together with
+ *   the Ticket it is keyed to, and a deleted Ticket takes the proposal keyed
+ *   to it along.
+ * - Collected signer arrays remain sorted, unique, and bounded.
+ */
+class ValidTransactionProposal
+{
+    // The Ticket each deleted proposal was keyed to; a proposal may go with
+    // its Ticket, or by Cancel, and no other way.
+    std::vector<uint256> ticketsOfDeletedProposals_;
+    // The proposal each deleted Ticket was keyed to, whether or not one
+    // existed; none may survive its Ticket.
+    std::vector<Keylet> proposalsOfDeletedTickets_;
+    std::set<uint256> deletedTickets_;
+    std::uint32_t created_ = 0;
+    std::uint32_t modified_ = 0;
+    std::uint32_t deleted_ = 0;
+    bool invalidSignerArrays_ = false;
+
+public:
+    void
+    visitEntry(bool isDelete, SLE::ConstRef before, SLE::ConstRef after);
+
+    [[nodiscard]] bool
+    finalize(STTx const& tx, TER result, XRPAmount, ReadView const& view, beast::Journal const& j)
+        const;
+};
+
+}  // namespace xrpl

include/xrpl/tx/invariants/InvariantCheck.h

@@ -1,12 +1,15 @@
 #pragma once
 
+#include <xrpl/basics/base_uint.h>
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/ledger/ReadView.h>
+#include <xrpl/protocol/AccountID.h>
 #include <xrpl/protocol/STLedgerEntry.h>
 #include <xrpl/protocol/STTx.h>
 #include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/invariants/AMMInvariant.h>
+#include <xrpl/tx/invariants/CosignerInvariant.h>
 #include <xrpl/tx/invariants/DirectoryInvariant.h>
 #include <xrpl/tx/invariants/FreezeInvariant.h>
 #include <xrpl/tx/invariants/LoanBrokerInvariant.h>
@@ -21,6 +24,7 @@
 #include <boost/multiprecision/cpp_int.hpp>
 
 #include <cstdint>
+#include <map>
 #include <set>
 #include <string>
 #include <tuple>
@@ -363,11 +367,27 @@ public:
  * unique to pseudo-accounts. Check that all pseudo-accounts are following the
  * rules, and that only pseudo-accounts look like pseudo-accounts.
  *
+ * Post-fixCleanup3_5_0, a pseudo-account also owns only entries that belong
+ * to its own AMM, Vault or LoanBroker:
+ * - AMM: its AMM entry, its holdings of the two pool assets, and the trust
+ *   lines of its LP token,
+ * - Vault: its share MPTokenIssuance, its holding of the vault asset, and the
+ *   LoanBrokers operating on this vault,
+ * - LoanBroker: its Loans and its holding of the vault asset (the cover).
+ *
+ * A pseudo-account cannot sign transactions, so it could never accept or
+ * remove any other object linked into its owner directory. Such an object
+ * would pin the directory and block deletion of the owning object.
  */
 class ValidPseudoAccounts
 {
     std::vector<std::string> errors_;
 
+    // Entries newly linked into owner directories, keyed by the directory
+    // owner. Whether an owner is a pseudo-account is decided in finalize,
+    // where the view is available.
+    std::map<AccountID, std::vector<uint256>> ownerDirAdditions_;
+
 public:
     void
     visitEntry(bool, SLE::ConstRef, SLE::ConstRef);
@@ -464,6 +484,7 @@ using InvariantChecks = std::tuple<
     ValidAmounts,
     ValidMPTTransfer,
     ObjectHasPseudoAccount,
+    ValidTransactionProposal,
     SponsorshipOwnerCountsMatch,
     SponsorshipAccountCountMatchesField>;
 

include/xrpl/tx/invariants/VaultInvariant.h

@@ -8,6 +8,7 @@
 #include <xrpl/protocol/AccountID.h>
 #include <xrpl/protocol/Asset.h>
 #include <xrpl/protocol/MPTIssue.h>
+#include <xrpl/protocol/Protocol.h>
 #include <xrpl/protocol/Rules.h>
 #include <xrpl/protocol/STLedgerEntry.h>
 #include <xrpl/protocol/STTx.h>
@@ -29,7 +30,7 @@ namespace xrpl {
  * - vault must have MPTokenIssuance for shares
  * - vault without shares outstanding must have no shares
  * - loss unrealized does not exceed the difference between assets total and
- *   assets available
+ *   assets available (Legacy/CashBasis), or AssetsDeployed (FixedPrecision)
  * - assets available do not exceed assets total
  * - vault deposit increases assets and share issuance, and adds to:
  *   total assets, assets available, shares outstanding
@@ -46,6 +47,14 @@ namespace xrpl {
  * - vault withdrawal may not succeed when the vault phase is Investment
  * - closed-ended loan origination (ttLOAN_SET) may only succeed when the
  *   vault phase is Investment
+ * - FixedPrecision only: AssetsDeployed is non-negative and exactly
+ *   representable at the asset's precision; AssetsDeployed changes only for
+ *   ttLOAN_SET, ttLOAN_PAY and ttLOAN_MANAGE; AssetsDeployed is zero right
+ *   after ttVAULT_CREATE and whenever shares outstanding return to zero; the
+ *   stored AssetsTotal cache equals AssetsAvailable + AssetsDeployed, rounded
+ *   Downward to the asset's precision
+ * - FixedPrecision only: YieldUnrealized is non-negative; YieldUnrealized
+ *   changes only for ttLOAN_SET, ttLOAN_PAY and ttLOAN_MANAGE
  *
  * Immutability of VaultKind, SubscriptionDate and RedemptionDate is enforced
  * by NoModifiedUnmodifiableFields (see InvariantCheck.cpp). From
@@ -68,6 +77,9 @@ class ValidVault
         Number assetsAvailable = 0;
         Number assetsMaximum = 0;
         Number lossUnrealized = 0;
+        Number assetsDeployed = 0;
+        Number yieldUnrealized = 0;
+        VaultVersion version = VaultVersion::Legacy;
         std::optional<std::uint8_t> vaultKind;
         std::optional<std::uint32_t> subscriptionDate;
         std::optional<std::uint32_t> redemptionDate;
@@ -217,6 +229,39 @@ private:
     [[nodiscard]] bool
     finalizeLoanSet(ReadView const& view, beast::Journal const& j) const;
 
+    /**
+     * @brief Check that a vault's AssetsTotal and AssetsAvailable deltas add
+     *        up against the real transfer, for deposit/withdraw/clawback.
+     *
+     * Shared body of the ttVAULT_DEPOSIT, ttVAULT_WITHDRAW and
+     * ttVAULT_CLAWBACK "assets outstanding"/"assets available" add-up checks,
+     * which differ only in the rounded/exact deltas plugged in and the verb
+     * used in the log message.
+     *
+     * @param afterVault Snapshot of the vault after the transaction.
+     * @param beforeVault Snapshot of the vault before the transaction.
+     * @param vaultAsset The vault's underlying asset.
+     * @param fix340Enabled Whether fixCleanup3_4_0 is enabled.
+     * @param minScale The posterior scale computed by computeVaultMinScale.
+     * @param roundedVaultDelta The real transfer's delta, rounded to minScale.
+     * @param exactVaultDelta The real transfer's exact (unrounded) delta.
+     * @param verb The transaction name used in the log message ("deposit",
+     *             "withdrawal" or "clawback").
+     * @param j Journal for logging.
+     * @return false if either add-up check fails.
+     */
+    [[nodiscard]] static bool
+    checkTotalsAddUp(
+        Vault const& afterVault,
+        Vault const& beforeVault,
+        Asset const& vaultAsset,
+        bool fix340Enabled,
+        std::int32_t minScale,
+        Number const& roundedVaultDelta,
+        Number const& exactVaultDelta,
+        char const* verb,
+        beast::Journal const& j);
+
 public:
     // Compute the coarsest scale required to represent all numbers
     [[nodiscard]] static std::int32_t

include/xrpl/tx/transactors/escrow/EscrowCreate.h

@@ -20,11 +20,14 @@ public:
     {
     }
 
+    static bool
+    checkExtraFeatures(PreflightContext const& ctx);
+
     static TxConsequences
     makeTxConsequences(PreflightContext const& ctx);
 
-    static bool
-    checkExtraFeatures(PreflightContext const& ctx);
+    static XRPAmount
+    calculateBaseFee(ReadView const& view, STTx const& tx);
 
     static NotTEC
     preflight(PreflightContext const& ctx);

include/xrpl/tx/transactors/lending/LoanManage.h

@@ -5,6 +5,7 @@
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/ReadView.h>
 #include <xrpl/protocol/Asset.h>
+#include <xrpl/protocol/STAmount.h>
 #include <xrpl/protocol/STTx.h>
 #include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/XRPAmount.h>
@@ -45,9 +46,29 @@ public:
         SLE::Ref loanSle,
         SLE::Ref brokerSle,
         SLE::Ref vaultSle,
-        Asset const& vaultAsset,
         beast::Journal j);
 
+    /**
+     * @brief Compute the First-Loss Capital cover amount for a defaulted Loan on a FixedPrecision
+     * Vault, capped at the LoanBroker's CoverAvailable and floored so that AssetsAvailable + cover
+     * is exactly on its posterior grid.
+     *
+     * The LoanBroker absorbs the rounding. When CoverAvailable - cover needs finer digits than the
+     * broker's posterior grid, it rounds to nearest, as the broker's trust line does, so
+     * CoverAvailable can move by up to half a posterior ulp more or less than the cover. When the
+     * two grids differ, no cover is exact on both sides; the Vault side is kept exact.
+     *
+     * The one exception: when AssetsAvailable has digits finer than the 16-digit cover can carry,
+     * no cover cancels them, and the balance writer rounds AssetsAvailable + cover to nearest,
+     * by at most half a posterior ulp. VaultDeposit and LoanPay credits have the same limit.
+     * @param loanSle The Loan being defaulted.
+     * @param brokerSle The Loan's LoanBroker.
+     * @param vaultSle The LoanBroker's Vault.
+     * @return The cover amount, in the Vault's Asset.
+     */
+    static STAmount
+    calculateDefaultCover(SLE::Ref loanSle, SLE::Ref brokerSle, SLE::Ref vaultSle);
+
     /**
      * Helper function that might be needed by other transactors
      */

include/xrpl/tx/transactors/proposal/TransactionProposalCancel.h

@@ -0,0 +1,44 @@
+#pragma once
+
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/ledger/ReadView.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/TER.h>
+#include <xrpl/protocol/XRPAmount.h>
+#include <xrpl/tx/ApplyContext.h>
+#include <xrpl/tx/Transactor.h>
+
+namespace xrpl {
+
+class TransactionProposalCancel : public Transactor
+{
+public:
+    static constexpr auto kConsequencesFactory = ConsequencesFactoryType::Normal;
+
+    explicit TransactionProposalCancel(ApplyContext& ctx) : Transactor(ctx)
+    {
+    }
+
+    static NotTEC
+    preflight(PreflightContext const& ctx);
+
+    static TER
+    preclaim(PreclaimContext const& ctx);
+
+    TER
+    doApply() override;
+
+    void
+    visitInvariantEntry(bool isDelete, SLE::ConstRef before, SLE::ConstRef after) override;
+
+    [[nodiscard]] bool
+    finalizeInvariants(
+        STTx const& tx,
+        TER result,
+        XRPAmount fee,
+        ReadView const& view,
+        beast::Journal const& j) override;
+};
+
+}  // namespace xrpl

include/xrpl/tx/transactors/system/Change.h

@@ -52,6 +52,13 @@ private:
     TER
     applyFee();
 
+    /**
+     * Write the default Feature Extension fee settings into FeeSettings on
+     * `featureSmartEscrow` activation.
+     */
+    void
+    initializeVMFees();
+
     TER
     applyUNLModify();
 };

src/libxrpl/json/json_value.cpp

@@ -15,7 +15,6 @@
 #include <cstring>
 #include <limits>
 #include <string>
-#include <string_view>
 #include <utility>
 
 namespace json {
@@ -242,14 +241,10 @@ Value::Value(xrpl::Number const& value) : type_(ValueType::String), allocated_(t
     value_.stringVal = valueAllocator()->duplicateStringValue(tmp.c_str(), tmp.length());
 }
 
-Value::Value(std::string const& value) : Value(std::string_view{value})
+Value::Value(std::string const& value) : type_(ValueType::String), allocated_(true)
 {
-}
-
-Value::Value(std::string_view value) : type_(ValueType::String), allocated_(true)
-{
-    value_.stringVal = valueAllocator()->duplicateStringValue(
-        value.data(), static_cast<unsigned int>(value.length()));
+    value_.stringVal =
+        valueAllocator()->duplicateStringValue(value.c_str(), (unsigned int)value.length());
 }
 
 Value::Value(StaticString const& value) : type_(ValueType::String)

src/libxrpl/ledger/Ledger.cpp

@@ -200,11 +200,23 @@ Ledger::Ledger(
                 sle->at(sfReserveIncrement) = *f;
             sle->at(sfReferenceFeeUnits) = kFeeUnitsDeprecated;
         }
+        if (std::ranges::find(amendments, featureSmartEscrow) != amendments.end())
+        {
+            sle->at(sfGasLimit) = fees.gasLimit;
+            sle->at(sfBytecodeSizeLimit) = fees.bytecodeSizeLimit;
+            sle->at(sfGasPrice) = fees.gasPrice;
+        }
         rawInsert(sle);
     }
 
     stateMap_.flushDirty(NodeObjectType::AccountNode);
-    setImmutable();
+    // Built locally. See Ledger::setImmutable().
+    if (!setImmutable())
+    {
+        // LCOV_EXCL_START
+        logicError("Ledger::Ledger(CreateGenesisT, ...): genesis ledger map is invalid");
+        // LCOV_EXCL_STOP
+    }
 }
 
 Ledger::Ledger(
@@ -215,7 +227,7 @@ Ledger::Ledger(
     Fees const& fees,
     Family& family,
     beast::Journal j)
-    : immutable_(true)
+    : immutable_(false)
     , txMap_(SHAMapType::TRANSACTION, info.txHash, family)
     , stateMap_(SHAMapType::STATE, info.accountHash, family)
     , fees_(fees)
@@ -238,8 +250,20 @@ Ledger::Ledger(
         JLOG(j.warn()) << "Don't have state data root for ledger" << header_.seq;
     }
 
-    txMap_.setImmutable();
-    stateMap_.setImmutable();
+    // Loaded locally. See Ledger::setImmutable().
+    if (setMapsImmutable())
+    {
+        immutable_ = true;
+    }
+    else
+    {
+        // LCOV_EXCL_START
+        JLOG(j.error()) << "Invalid map for ledger " << header_.seq;
+        UNREACHABLE("xrpl::Ledger::Ledger(LedgerHeader const&, ...) : map is invalid");
+        // Treat it as a damaged ledger: the code below recomputes the hash and re-acquires.
+        loaded = false;
+        // LCOV_EXCL_STOP
+    }
 
     if (!setup())
         loaded = false;
@@ -310,27 +334,50 @@ Ledger::Ledger(
     setup();
 }
 
-void
+bool
 Ledger::setImmutable(bool rehash)
 {
-    // Force update, since this is the only
-    // place the hash transitions to valid
-    if (!immutable_ && rehash)
+    // A map found structurally invalid during sync must never be made immutable: isValid() tests
+    // only for Invalid, and an immutable ledger is treated as persistable. Asked before anything is
+    // written, so a refusal leaves the header exactly as it was rather than half relabeled.
+    if (!mapsValid())
+        return false;
+
+    // Read here but written to the header below, once the maps are settled: getHash() can unshare a
+    // dirty tree, so it has to run while the map is still mutable, while a write to the header must
+    // wait until both maps have made it. Skipped once the ledger is immutable, since its maps can
+    // no longer change.
+    bool const deriveMapHashes = !immutable_ && rehash;
+    UInt256 const txHash = deriveMapHashes ? txMap_.getHash().asUInt256() : UInt256{};
+    UInt256 const accountHash = deriveMapHashes ? stateMap_.getHash().asUInt256() : UInt256{};
+
+    // Both were valid at the check above, but a concurrent walk can invalidate one in between (see
+    // SHAMap::state_), so the result is checked. setInvalid() outranks Immutable and can land
+    // after both maps have been settled, so this narrows the window it guards.
+    bool const bothImmutable = setMapsImmutable();
+    SOMETIMES(!bothImmutable, "xrpl::Ledger::setImmutable : map invalidated while going immutable");
+    if (!bothImmutable)
+        return false;
+
+    // Written only now, so losing the race above leaves the header describing what the ledger was
+    // built from rather than a map that has since been abandoned. Forced rather than conditional,
+    // since this is the only place the hash transitions to valid.
+    if (deriveMapHashes)
     {
-        header_.txHash = txMap_.getHash().asUInt256();
-        header_.accountHash = stateMap_.getHash().asUInt256();
+        header_.txHash = txHash;
+        header_.accountHash = accountHash;
     }
 
     if (rehash)
         header_.hash = calculateLedgerHash(header_);
 
+    // Set last, so isImmutable() reports only a ledger whose maps are both immutable.
     immutable_ = true;
-    txMap_.setImmutable();
-    stateMap_.setImmutable();
     setup();
+    return true;
 }
 
-void
+bool
 Ledger::setAccepted(
     NetClock::time_point closeTime,
     NetClock::duration closeResolution,
@@ -342,7 +389,17 @@ Ledger::setAccepted(
     header_.closeTime = closeTime;
     header_.closeTimeResolution = closeResolution;
     header_.closeFlags = correctCloseTime ? 0 : kSLcfNoConsensusTime;
-    setImmutable();
+    // Built locally. See Ledger::setImmutable().
+    if (!setImmutable())
+    {
+        // LCOV_EXCL_START
+        JLOG(j_.error()) << "Invalid map for accepted ledger " << header_.seq;
+        UNREACHABLE("xrpl::Ledger::setAccepted : map is invalid");
+        return false;
+        // LCOV_EXCL_STOP
+    }
+
+    return true;
 }
 
 bool
@@ -566,6 +623,7 @@ Ledger::setup()
         {
             bool oldFees = false;
             bool newFees = false;
+            bool extensionFees = false;
             {
                 auto const baseFee = sle->at(~sfBaseFee);
                 auto const reserveBase = sle->at(~sfReserveBase);
@@ -600,6 +658,20 @@ Ledger::setup()
                 assign(fees_.increment, reserveIncrementXRP);
                 newFees = baseFeeXRP || reserveBaseXRP || reserveIncrementXRP;
             }
+            {
+                auto const gasLimit = sle->at(~sfGasLimit);
+                auto const bytecodeSizeLimit = sle->at(~sfBytecodeSizeLimit);
+                auto const gasPrice = sle->at(~sfGasPrice);
+
+                // An absent field resolves to the protocol constant.
+                if (rules_.enabled(featureSmartEscrow))
+                {
+                    fees_.gasLimit = gasLimit.value_or(kDefaultGasLimit);
+                    fees_.bytecodeSizeLimit = bytecodeSizeLimit.value_or(kDefaultBytecodeSizeLimit);
+                    fees_.gasPrice = gasPrice.value_or(kDefaultGasPrice);
+                }
+                extensionFees = gasLimit || bytecodeSizeLimit || gasPrice;
+            }
             if (oldFees && newFees)
             {
                 // Should be all of one or the other, but not both
@@ -610,6 +682,12 @@ Ledger::setup()
                 // Can't populate the new fees before the amendment is enabled
                 ret = false;
             }
+            if (!rules_.enabled(featureSmartEscrow) && extensionFees)
+            {
+                // Can't populate the extension fees before the amendment is
+                // enabled
+                ret = false;
+            }
         }
     }
     catch (SHAMapMissingNode const&)

src/libxrpl/ledger/PaymentSandbox.cpp

@@ -435,8 +435,6 @@ PaymentSandbox::issuerSelfDebitHookMPT(
     std::uint64_t amount,
     std::int64_t origBalance)
 {
-    XRPL_ASSERT(amount > 0, "PaymentSandbox::issuerSelfDebitHookMPT: amount must be > 0");
-
     tab_.issuerSelfDebitMPT(issue, amount, origBalance);
 }
 

src/libxrpl/ledger/View.cpp

@@ -511,9 +511,14 @@ doWithdraw(
     AccountID const& dstAcct,
     AccountID const& sourceAcct,
     XRPAmount priorBalance,
-    STAmount const& amount,
+    STAmount const& destinationAmount,
+    STAmount const& sourceAmount,
     beast::Journal j)
 {
+    XRPL_ASSERT(
+        destinationAmount.asset() == sourceAmount.asset(),
+        "xrpl::doWithdraw : delivered and source amounts use the same asset");
+
     auto const dstSle = ctx.view.read(keylet::account(dstAcct));
 
     // Create a trust line or MPToken for a self-destination only when there
@@ -523,9 +528,10 @@ doWithdraw(
     // create+delete MPTokens in the same transaction.
     if (dstAcct == senderAcct)
     {
-        if (amount > beast::kZero || !ctx.view.rules().enabled(fixCleanup3_4_0))
+        if (destinationAmount > beast::kZero || !ctx.view.rules().enabled(fixCleanup3_4_0))
         {
-            if (auto const ter = addEmptyHolding(ctx, senderAcct, priorBalance, amount.asset(), j);
+            if (auto const ter =
+                    addEmptyHolding(ctx, senderAcct, priorBalance, destinationAmount.asset(), j);
                 !isTesSuccess(ter) && ter != tecDUPLICATE)
                 return ter;
         }
@@ -540,17 +546,33 @@ doWithdraw(
     if (accountHolds(
             ctx.view,
             sourceAcct,
-            amount.asset(),
+            destinationAmount.asset(),
             FreezeHandling::IgnoreFreeze,
             AuthHandling::IgnoreAuth,
-            j) < amount)
+            j) < sourceAmount)
     {
         // LCOV_EXCL_START
-        JLOG(j.error()) << "doWithdraw: negative balance of broker cover assets.";
+        JLOG(j.error()) << "doWithdraw: source account holds fewer assets than the withdrawal.";
         return tefINTERNAL;
         // LCOV_EXCL_STOP
     }
 
+    // A transfer fee applies. Redeem the gross amount with the issuer, then
+    // issue the net amount to the destination.
+    if (sourceAmount != destinationAmount)
+    {
+        auto const issuer = destinationAmount.getIssuer();
+        XRPL_ASSERT(
+            !destinationAmount.native() && sourceAcct != issuer && dstAcct != issuer,
+            "xrpl::doWithdraw : transfer fee applies between token holders");
+
+        if (auto const ter = directSendNoFee(ctx.view, sourceAcct, issuer, sourceAmount, false, j);
+            !isTesSuccess(ter))
+            return ter;  // LCOV_EXCL_LINE
+
+        return directSendNoFee(ctx.view, issuer, dstAcct, destinationAmount, false, j);
+    }
+
     // A reserve sponsor only covers tx.Account's own objects, so resolve the
     // sponsor against the destination. accountSend can auto-create a holding
     // for dstAcct; keying on the destination ensures a third-party destination's
@@ -562,7 +584,7 @@ doWithdraw(
     // Move the funds directly from the broker's pseudo-account to the
     // dstAcct
     return accountSend(
-        ctx.view, sourceAcct, dstAcct, amount, j, *sponsorSle, WaiveTransferFee::Yes);
+        ctx.view, sourceAcct, dstAcct, destinationAmount, j, *sponsorSle, WaiveTransferFee::Yes);
 }
 
 TER

src/libxrpl/ledger/helpers/AMMHelpers.cpp

@@ -213,49 +213,19 @@ adjustAmountsByLPTokens(
 
     if (lpTokensActual < lpTokens)
     {
-        bool const ammRoundingEnabled = [&] {
-            if (auto const& rules = getCurrentTransactionRules();
-                rules && rules->enabled(fixAMMv1_1))
-                return true;
-            return false;
-        }();
-
         // Equal trade
         if (amount2)
         {
             Number const fr = lpTokensActual / lpTokens;
             auto const amountActual = toSTAmount(amount.asset(), fr * amount);
             auto const amount2Actual = toSTAmount(amount2->asset(), fr * *amount2);
-            if (!ammRoundingEnabled)
-            {
-                return std::make_tuple(
-                    amountActual < amount ? amountActual : amount,
-                    amount2Actual < amount2 ? amount2Actual : amount2,
-                    lpTokensActual);
-            }
-
             return std::make_tuple(amountActual, amount2Actual, lpTokensActual);
         }
 
         // Single trade
-        auto const amountActual = [&] {
-            if (isDeposit == IsDeposit::Yes)
-            {
-                return ammAssetIn(amountBalance, lptAMMBalance, lpTokensActual, tfee);
-            }
-            if (!ammRoundingEnabled)
-            {
-                return ammAssetOut(amountBalance, lptAMMBalance, lpTokens, tfee);
-            }
-
-            return ammAssetOut(amountBalance, lptAMMBalance, lpTokensActual, tfee);
-        }();
-        if (!ammRoundingEnabled)
-        {
-            return amountActual < amount
-                ? std::make_tuple(amountActual, std::nullopt, lpTokensActual)
-                : std::make_tuple(amount, std::nullopt, lpTokensActual);
-        }
+        auto const amountActual = isDeposit == IsDeposit::Yes
+            ? ammAssetIn(amountBalance, lptAMMBalance, lpTokensActual, tfee)
+            : ammAssetOut(amountBalance, lptAMMBalance, lpTokensActual, tfee);
 
         return std::make_tuple(amountActual, std::nullopt, lpTokensActual);
     }
@@ -980,7 +950,7 @@ verifyAndAdjustLPTokenBalance(
         }
         else
         {
-            return std::unexpected<TER>(tecAMM_INVALID_TOKENS);
+            return std::unexpected<TER>(tecAMM_INVALID_TOKENS);  // LCOV_EXCL_LINE
         }
     }
     return true;

src/libxrpl/ledger/helpers/LendingHelpers.cpp

@@ -66,6 +66,161 @@ canApplyToBrokerCover(
     return tesSUCCESS;
 }
 
+namespace detail {
+
+[[nodiscard]] int
+getPosteriorBrokerCoverScale(SLE::ConstRef vault, SLE::ConstRef broker, Number const& delta)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT,
+        "xrpl::detail::getPosteriorBrokerCoverScale : valid Vault sle");
+    XRPL_ASSERT(
+        broker && broker->getType() == ltLOAN_BROKER,
+        "xrpl::detail::getPosteriorBrokerCoverScale : valid LoanBroker sle");
+
+    return posteriorAssetScale(
+        getVaultVersion(vault),
+        vault->at(sfAsset),
+        getVaultBaseScale(vault),
+        broker->at(sfCoverAvailable),
+        delta);
+}
+
+[[nodiscard]] STAmount
+roundToPosteriorBrokerCoverScale(
+    SLE::ConstRef vault,
+    SLE::ConstRef broker,
+    STAmount const& delta,
+    Number::RoundingMode roundingMode)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT,
+        "xrpl::detail::roundToPosteriorBrokerCoverScale : valid Vault sle");
+    XRPL_ASSERT(
+        broker && broker->getType() == ltLOAN_BROKER,
+        "xrpl::detail::roundToPosteriorBrokerCoverScale : valid LoanBroker sle");
+    XRPL_ASSERT(
+        delta.asset() == vault->at(sfAsset),
+        "xrpl::detail::roundToPosteriorBrokerCoverScale : delta and Vault asset match");
+    if (delta.integral())
+        return delta;
+    return roundToScale(delta, getPosteriorBrokerCoverScale(vault, broker, delta), roundingMode);
+}
+
+}  // namespace detail
+
+[[nodiscard]] STAmount
+creditToPosteriorBrokerCoverScale(
+    SLE::ConstRef vault,
+    SLE::ConstRef broker,
+    Number const& raw,
+    Number::RoundingMode roundingMode)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT,
+        "xrpl::creditToPosteriorBrokerCoverScale : valid Vault sle");
+    XRPL_ASSERT(
+        broker && broker->getType() == ltLOAN_BROKER,
+        "xrpl::creditToPosteriorBrokerCoverScale : valid LoanBroker sle");
+    Asset const asset = vault->at(sfAsset);
+    if (asset.integral())
+    {
+        NumberRoundModeGuard const rg(roundingMode);
+        return STAmount{asset, raw};
+    }
+
+    Number const reference = broker->at(sfCoverAvailable);
+    return detail::creditToPosteriorScale(
+        asset, reference, getVaultBaseScale(vault), raw, roundingMode);
+}
+
+[[nodiscard]] STAmount
+debitToPosteriorBrokerCoverScale(
+    SLE::ConstRef vault,
+    SLE::ConstRef broker,
+    STAmount const& amount,
+    Number::RoundingMode roundingMode)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT,
+        "xrpl::debitToPosteriorBrokerCoverScale : valid Vault sle");
+    XRPL_ASSERT(
+        broker && broker->getType() == ltLOAN_BROKER,
+        "xrpl::debitToPosteriorBrokerCoverScale : valid LoanBroker sle");
+    XRPL_ASSERT(
+        amount.asset() == vault->at(sfAsset),
+        "xrpl::debitToPosteriorBrokerCoverScale : amount and Vault asset match");
+    XRPL_ASSERT(!amount.negative(), "xrpl::debitToPosteriorBrokerCoverScale : non-negative amount");
+    return -detail::roundToPosteriorBrokerCoverScale(vault, broker, -amount, roundingMode);
+}
+
+[[nodiscard]] TER
+checkOptionalBrokerCoverInflow(SLE::ConstRef vault, SLE::ConstRef broker, STAmount const& amount)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT,
+        "xrpl::checkOptionalBrokerCoverInflow : valid Vault sle");
+    XRPL_ASSERT(
+        broker && broker->getType() == ltLOAN_BROKER,
+        "xrpl::checkOptionalBrokerCoverInflow : valid LoanBroker sle");
+    XRPL_ASSERT(
+        amount.asset() == vault->at(sfAsset),
+        "xrpl::checkOptionalBrokerCoverInflow : amount and Vault asset match");
+    XRPL_ASSERT(!amount.negative(), "xrpl::checkOptionalBrokerCoverInflow : non-negative amount");
+    if (getVaultVersion(vault) != VaultVersion::FixedPrecision)
+        return tesSUCCESS;
+
+    // amount is the effective credit (already floored on the posterior
+    // CoverAvailable grid by creditToPosteriorBrokerCoverScale); rounding it
+    // again as a standalone delta could hide a crossing.
+    STAmount const& rounded = amount;
+    int const baseScale = getVaultBaseScale(vault);
+    // Keep this explicit even though the Open-limit capacity check below rejects
+    // every coarsening transition too. The protocol defines both conditions
+    // independently.
+    if (detail::getPosteriorBrokerCoverScale(vault, broker, rounded) != baseScale)
+        return tecLIMIT_EXCEEDED;
+
+    Number const posterior = [&] {
+        NumberRoundModeGuard const rg(Number::RoundingMode::TowardsZero);
+        return broker->at(sfCoverAvailable) + rounded;
+    }();
+    if (posterior > getVaultOpenLimit(vault))
+        return tecLIMIT_EXCEEDED;
+    return tesSUCCESS;
+}
+
+void
+adjustBrokerDebtTotal(
+    SLE::Ref brokerSle,
+    SLE::ConstRef vaultSle,
+    Number const& delta,
+    int vaultScale)
+{
+    // On FixedPrecision Vaults, LoanSet adds principal to DebtTotal exactly, LoanPay and default
+    // subtract exact amounts. Thus DebtTotal must not be rounded coarser than the base scale.
+    if (getVaultVersion(vaultSle) == VaultVersion::FixedPrecision)
+    {
+        brokerSle->at(sfDebtTotal) += delta;
+    }
+    else
+    {
+        adjustImpreciseNumber(brokerSle->at(sfDebtTotal), delta, vaultSle->at(sfAsset), vaultScale);
+    }
+}
+
+Number
+minimumBrokerCover(Number const& debtTotal, TenthBips32 coverRateMinimum, SLE::ConstRef vaultSle)
+{
+    XRPL_ASSERT(
+        vaultSle && vaultSle->getType() == ltVAULT, "xrpl::minimumBrokerCover : valid Vault sle");
+    NumberRoundModeGuard const mg(Number::RoundingMode::Upward);
+    return roundToAsset(
+        vaultSle->at(sfAsset),
+        tenthBipsOfValue(debtTotal, coverRateMinimum),
+        getVaultBaseScale(vaultSle));
+}
+
 bool
 checkLendingProtocolDependencies(Rules const& rules, STTx const& tx)
 {
@@ -250,14 +405,13 @@ loanPaymentDeltas(LoanPaymentParts const& parts)
 
 namespace {
 
-// Cash-basis accounting applies only when featureLendingProtocolV1_1 is
-// enabled AND the specific Vault was created under it (LEVersion ==
-// VaultVersion::CashBasis). Vaults created before activation keep instant
-// interest recognition forever, even after the amendment later turns on.
+// Cash-basis accounting applies to Vaults created under
+// featureLendingProtocolV1_1 or a later version. Vaults created before
+// activation keep instant interest recognition forever.
 bool
 cashBasisEnabled(SLE::ConstRef vaultSle)
 {
-    return getVaultVersion(vaultSle) == VaultVersion::CashBasis;
+    return getVaultVersion(vaultSle) >= VaultVersion::CashBasis;
 }
 
 }  // namespace

src/libxrpl/ledger/helpers/MPTokenHelpers.cpp

@@ -1047,6 +1047,14 @@ maxMPTAmount(SLE const& sleIssuance)
     return sleIssuance[~sfMaximumAmount].value_or(kMaxMpTokenAmount);
 }
 
+std::optional<std::int64_t>
+maxMPTAmount(ReadView const& view, MPTID const& mptID)
+{
+    if (auto const sle = view.read(keylet::mptokenIssuance(mptID)))
+        return maxMPTAmount(*sle);
+    return std::nullopt;
+}
+
 std::int64_t
 availableMPTAmount(SLE const& sleIssuance)
 {

src/libxrpl/ledger/helpers/ProposalHelpers.cpp

@@ -1,18 +1,54 @@
 #include <xrpl/ledger/helpers/ProposalHelpers.h>
 
+#include <xrpl/basics/Log.h>
+#include <xrpl/basics/Slice.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/beast/utility/instrumentation.h>
+#include <xrpl/ledger/ApplyView.h>
+#include <xrpl/ledger/ReadView.h>
+#include <xrpl/ledger/View.h>
+#include <xrpl/ledger/helpers/AccountRootHelpers.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/Keylet.h>
+#include <xrpl/protocol/LedgerFormats.h>
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/STArray.h>
+#include <xrpl/protocol/STLedgerEntry.h>
 #include <xrpl/protocol/STObject.h>
 #include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/Serializer.h>
+#include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/TxFlags.h>
 #include <xrpl/protocol/TxFormats.h>
 
+#include <algorithm>
+#include <array>
+#include <cstdint>
+#include <optional>
+
 namespace xrpl::proposal {
 
+namespace {
+
+// Proposals do not nest, so a proposed transaction may carry none of these
+// types, neither as its own payload nor as a Batch inner transaction.
+constexpr auto kProposalTxTypes = std::to_array<TxType>({
+    ttTRANSACTION_PROPOSAL_CREATE,
+    ttTRANSACTION_PROPOSAL_CANCEL,
+});
+
+}  // namespace
+
 bool
-isValidProposal(STObject const& proposedTx)
+isValidProposalTxnType(STObject const& proposedTx)
 {
-    if (isProposalTx(proposedTx))
+    if (!proposedTx.isFieldPresent(sfTransactionType))
+        return false;
+
+    auto const type = proposedTx.getFieldU16(sfTransactionType);
+
+    if (std::ranges::find(kProposalTxTypes, type) != kProposalTxTypes.end())
         return false;
 
     if (isPseudoTx(proposedTx))
@@ -22,13 +58,24 @@ isValidProposal(STObject const& proposedTx)
         (proposedTx.getFieldU32(sfFlags) & tfInnerBatchTxn) != 0u)
         return false;
 
-    if (proposedTx.getFieldU16(sfTransactionType) == ttBATCH &&
-        proposedTx.isFieldPresent(sfRawTransactions))
+    if (type == ttBATCH && proposedTx.isFieldPresent(sfRawTransactions))
     {
         STArray const& innerTxns = proposedTx.getFieldArray(sfRawTransactions);
         for (STObject const& inner : innerTxns)
         {
-            if (isProposalTx(inner) || isPseudoTx(inner))
+            // The only production caller reaches this walk through STTx
+            // construction, which rejects a typeless inner first, so this is
+            // re-checked rather than relied upon.
+            if (!inner.isFieldPresent(sfTransactionType))
+                return false;
+
+            auto const innerType = inner.getFieldU16(sfTransactionType);
+
+            // A nested Batch is rejected alongside nested proposals and
+            // pseudo-transactions: STTx construction forbids inner Batches, so
+            // a proposal must not be able to store one either.
+            if (std::ranges::find(kProposalTxTypes, innerType) != kProposalTxTypes.end() ||
+                innerType == ttBATCH || isPseudoTx(inner))
                 return false;
         }
     }
@@ -36,4 +83,112 @@ isValidProposal(STObject const& proposedTx)
     return true;
 }
 
+bool
+isTerminal(
+    ReadView const& view,
+    std::optional<std::uint32_t> expiration,
+    STObject const& proposedTx)
+{
+    if (hasExpired(view, expiration))
+        return true;
+
+    // Mirror the ordinary transactor's tefMAX_LEDGER rule: view.seq() > bound.
+    // At view.seq() == bound the payload can still be submitted, so the
+    // proposal is still live (On-Chain Cosigner spec §4.5).
+    return proposedTx.isFieldPresent(sfLastLedgerSequence) &&
+        view.seq() > proposedTx.getFieldU32(sfLastLedgerSequence);
+}
+
+TER
+deleteProposal(ApplyView& view, SLE::pointer const& sleProposal, beast::Journal j)
+{
+    if (!sleProposal || sleProposal->getType() != ltTRANSACTION_PROPOSAL ||
+        !view.exists(Keylet{ltTRANSACTION_PROPOSAL, sleProposal->key()}))
+    {
+        // LCOV_EXCL_START
+        JLOG(j.fatal()) << "Invalid TransactionProposal deletion.";
+        return tecINTERNAL;
+        // LCOV_EXCL_STOP
+    }
+
+    AccountID const owner = sleProposal->getAccountID(sfOwner);
+
+    std::uint64_t const page{(*sleProposal)[sfOwnerNode]};
+    if (!view.dirRemove(keylet::ownerDir(owner), page, sleProposal->key(), true))
+    {
+        // LCOV_EXCL_START
+        JLOG(j.fatal()) << "Unable to delete TransactionProposal from owner.";
+        return tefBAD_LEDGER;
+        // LCOV_EXCL_STOP
+    }
+
+    auto const sleOwner = view.peek(keylet::account(owner));
+    if (!sleOwner)
+    {
+        // LCOV_EXCL_START
+        JLOG(j.fatal()) << "Could not find TransactionProposal owner account root.";
+        return tefBAD_LEDGER;
+        // LCOV_EXCL_STOP
+    }
+
+    // Release the reserve against the Owner or, if the entry carries a
+    // reserve sponsor, against that sponsor.
+    decreaseOwnerCountForObject(
+        view,
+        sleOwner,
+        sleProposal,
+        proposalOwnerCount(sleProposal->getFieldObject(sfProposedTransaction)),
+        j);
+
+    view.erase(sleProposal);
+    return tesSUCCESS;
+}
+
+bool
+payloadMatches(STObject const& proposedTx, STObject const& tx)
+{
+    XRPL_ASSERT(
+        proposedTx.isFieldPresent(sfTransactionType) && tx.isFieldPresent(sfTransactionType),
+        "xrpl::proposal::payloadMatches : transaction-shaped inputs");
+
+    // The signing-payload serialization omits every kNotSigning field: the
+    // signature containers a proposal lets evolve (TxnSignature, Signers,
+    // BatchSigners, CounterpartySignature, SponsorSignature) plus Signature
+    // and MasterSignature, which the account's own signature does not cover
+    // either (see the header). What remains is the field set fixed at
+    // creation — except SigningPubKey, which signing payloads include but
+    // which is also mutable here (stored empty, filled if the target signs
+    // with its own key). Neutralize it on both sides before comparing.
+    auto const payloadBytes = [](STObject const& obj) {
+        STObject copy{obj};
+        copy.setFieldVL(sfSigningPubKey, Slice{});
+        Serializer s;
+        copy.addWithoutSigningFields(s);
+        return s.getData();
+    };
+
+    return payloadBytes(proposedTx) == payloadBytes(tx);
+}
+
+bool
+canConsumeTicket(ReadView const& view, STTx const& tx)
+{
+    auto const seqProx = tx.getSeqProxy();
+    if (!seqProx.isTicket())
+    {
+        // The caller only reaches here for a Ticket-based transaction.
+        // LCOV_EXCL_START
+        UNREACHABLE("xrpl::proposal::canConsumeTicket : tx spends a Sequence");
+        return false;
+        // LCOV_EXCL_STOP
+    }
+
+    auto const sleProposal =
+        view.read(keylet::txProposal(tx.getAccountID(sfAccount), seqProx.value()));
+    if (!sleProposal)
+        return true;
+
+    return payloadMatches(sleProposal->getFieldObject(sfProposedTransaction), tx);
+}
+
 }  // namespace xrpl::proposal

src/libxrpl/ledger/helpers/SponsorHelpers.cpp

@@ -4,6 +4,7 @@
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/ReadView.h>
 #include <xrpl/ledger/helpers/AccountRootHelpers.h>
+#include <xrpl/ledger/helpers/EscrowHelpers.h>
 #include <xrpl/ledger/helpers/OracleHelpers.h>
 #include <xrpl/ledger/helpers/ProposalHelpers.h>
 #include <xrpl/protocol/AccountID.h>
@@ -319,6 +320,8 @@ getLedgerEntryOwnerCount(SLE const& sle)
             UNREACHABLE("AccountRoots are not supported by object sponsorship.");
             return 0;
             // LCOV_EXCL_STOP
+        case ltESCROW:
+            return calculateAdditionalReserve(sle[~sfBytecode]);
         default:
             return 1;
     }

src/libxrpl/ledger/helpers/TokenHelpers.cpp

@@ -2,6 +2,7 @@
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/MathUtilities.h>
+#include <xrpl/basics/Number.h>
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/beast/utility/Zero.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -551,6 +552,22 @@ transferRate(ReadView const& view, STAmount const& amount)
     return transferRate(view, amount.asset());
 }
 
+STAmount
+addTransferFee(STAmount const& amount, Rate const& rate)
+{
+    if (rate == kParityRate)
+        return amount;
+    return mulRatio(amount, rate.value, QUALITY_ONE, Number::RoundingMode::Upward);
+}
+
+STAmount
+subtractTransferFee(STAmount const& amount, Rate const& rate)
+{
+    if (rate == kParityRate)
+        return amount;
+    return mulRatio(amount, QUALITY_ONE, rate.value, Number::RoundingMode::Downward);
+}
+
 //------------------------------------------------------------------------------
 //
 // Holding operations
@@ -973,19 +990,11 @@ accountSendIOU(
     SLE::Ref sponsorSle,
     WaiveTransferFee waiveFee)
 {
-    if (view.rules().enabled(fixAMMv1_1))
-    {
-        if (saAmount < beast::kZero || saAmount.holds<MPTIssue>())
-        {
-            return tecINTERNAL;  // LCOV_EXCL_LINE
-        }
-    }
-    else
+    if (saAmount < beast::kZero || saAmount.holds<MPTIssue>())
     {
         // LCOV_EXCL_START
-        XRPL_ASSERT(
-            saAmount >= beast::kZero && !saAmount.holds<MPTIssue>(),
-            "xrpl::accountSendIOU : minimum amount and not MPT");
+        JLOG(j.fatal()) << "accountSendIOU: negative amount or invalid asset";
+        return tecINTERNAL;
         // LCOV_EXCL_STOP
     }
 
@@ -1355,9 +1364,8 @@ directSendNoLimitMPT(
         {
             // Number math loses precision on large MPT amounts, which can
             // overcharge the sender. MPTs are integral, so compute the cost
-            // exactly and round it up, matching the payment engine.
-            auto const cost = mulRatio(saAmount.mpt(), rate.value, QUALITY_ONE, true);
-            saActual = STAmount(saAmount.asset(), cost.value());
+            // exactly, matching the payment engine.
+            saActual = addTransferFee(saAmount, rate);
         }
         else
         {
@@ -1482,9 +1490,8 @@ directSendNoLimitMultiMPT(
             {
                 // Number math loses precision on large MPT amounts, which can
                 // overcharge the sender. MPTs are integral, so compute the
-                // cost exactly and round it up, matching the payment engine.
-                auto const cost = mulRatio(amount.mpt(), rate.value, QUALITY_ONE, true);
-                actualSend = STAmount(amount.asset(), cost.value());
+                // cost exactly, matching the payment engine.
+                actualSend = addTransferFee(amount, rate);
             }
             else
             {

src/libxrpl/ledger/helpers/VaultHelpers.cpp

@@ -1,12 +1,16 @@
 #include <xrpl/ledger/helpers/VaultHelpers.h>
 
+#include <xrpl/basics/Log.h>
 #include <xrpl/basics/Number.h>
+#include <xrpl/beast/utility/Journal.h>
 #include <xrpl/beast/utility/Zero.h>
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/ledger/ReadView.h>
 #include <xrpl/ledger/View.h>
 #include <xrpl/ledger/helpers/CredentialHelpers.h>
 #include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/Asset.h>
+#include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/Indexes.h>
 #include <xrpl/protocol/LedgerFormats.h>  // IWYU pragma: keep
 #include <xrpl/protocol/Protocol.h>
@@ -17,13 +21,480 @@
 #include <xrpl/protocol/STTx.h>
 #include <xrpl/protocol/TER.h>
 
+#include <algorithm>
 #include <cstdint>
 #include <expected>
 #include <optional>
+#include <stdexcept>
+#include <string_view>
 #include <utility>
 
 namespace xrpl {
 
+namespace {
+
+[[nodiscard]] int
+fixedBaseScale(SLE::ConstRef vault)
+{
+    XRPL_ASSERT(vault && vault->getType() == ltVAULT, "xrpl::fixedBaseScale : valid Vault sle");
+    Asset const asset = vault->at(sfAsset);
+    // sfScale is never written for an integral asset (VaultCreate only sets
+    // it when scale != 0, and integral assets always get scale 0), so it
+    // must not be read here; vaultBaseScale ignores the scale argument for
+    // an integral asset anyway.
+    if (asset.integral())
+        return 0;
+    return vaultBaseScale(asset, vault->at(sfScale));
+}
+
+// Thin, vault-specific wrapper over posteriorAssetScale: used by
+// getPosteriorVaultScale and the cash outflow rounding below.
+[[nodiscard]] int
+posteriorScale(SLE::ConstRef vault, Number const& reference, Number const& delta)
+{
+    return detail::posteriorAssetScale(
+        getVaultVersion(vault), vault->at(sfAsset), fixedBaseScale(vault), reference, delta);
+}
+
+// FixedPrecision-only counterpart to clampToAssetsTotalScale, for cash
+// outflows (VaultWithdraw, VaultClawback): rounds the magnitude of delta
+// toward zero at AssetsAvailable's own posterior scale, the balance the cash
+// actually leaves, instead of the derived AssetsTotal cache. Same
+// tecPRECISION_LOSS and integral-asset and magnitude-never-exceeds-delta
+// rules as clampToAssetsTotalScale. Not part of the public interface; reached
+// only through clampVaultOutflow.
+//
+// For an outflow it is safe to round the delta directly, unlike the credit
+// case: amount on the posterior grid of AssetsAvailable always leaves
+// AssetsAvailable minus amount representable, since the posterior grid is
+// exactly the grid AssetsAvailable itself will canonicalize to after the
+// subtraction.
+[[nodiscard]] std::expected<STAmount, TER>
+clampToAvailableScale(SLE::ConstRef vault, STAmount const& delta)
+{
+    XRPL_ASSERT(
+        delta.asset() == vault->at(sfAsset),
+        "xrpl::clampToAvailableScale : delta and vault asset match");
+    XRPL_ASSERT(
+        getVaultVersion(vault) == VaultVersion::FixedPrecision,
+        "xrpl::clampToAvailableScale : FixedPrecision Vault");
+    XRPL_ASSERT(delta.negative(), "xrpl::clampToAvailableScale : outflow delta is negative");
+
+    Asset const asset = vault->at(sfAsset);
+    STAmount magnitude = delta.negative() ? -delta : delta;
+    if (asset.integral())
+        return magnitude;
+
+    STAmount const rounded = roundToScale(
+        delta,
+        posteriorScale(vault, vault->at(sfAssetsAvailable), delta),
+        Number::RoundingMode::TowardsZero);
+    STAmount actualDelta = rounded.negative() ? -rounded : rounded;
+
+    XRPL_ASSERT(
+        abs(actualDelta) <= abs(delta),
+        "xrpl::clampToAvailableScale : actual delta smaller or equal to calculated delta");
+
+    // Reject changes below scale precision (1 ULP) to prevent share balance changes
+    // without corresponding asset movements.
+    if (actualDelta <= beast::kZero)
+        return std::unexpected(tecPRECISION_LOSS);
+
+    return actualDelta;
+}
+
+[[nodiscard]] VaultKind
+decodeVaultKind(std::optional<std::uint8_t> vaultKind)
+{
+    if (vaultKind && *vaultKind == std::to_underlying(VaultKind::ClosedEnded))
+        return VaultKind::ClosedEnded;
+    return VaultKind::OpenEnded;
+}
+
+// Write cached AssetsTotal from getAssetsTotal, as the exact total rounded
+// Downward to the Vault asset's 16-digit STAmount representation. Below
+// coarsening this equals the exact total; above it, the cache is a
+// deliberate floor of the exact value. Internal to adjustVaultBalances,
+// the only writer of AssetsAvailable, AssetsDeployed, AssetsTotal,
+// YieldUnrealized and LossUnrealized on a FixedPrecision Vault after
+// creation; not part of the public interface.
+void
+syncAssetsTotal(SLE::Ref vault)
+{
+    XRPL_ASSERT(vault && vault->getType() == ltVAULT, "xrpl::syncAssetsTotal : valid Vault sle");
+    Asset const asset = vault->at(sfAsset);
+
+    // adjustVaultBalances writes AssetsAvailable as an already-canonical
+    // STAmount before calling this, so the associateAsset pass a transactor
+    // runs afterwards is always a no-op. If this fires, AssetsAvailable was
+    // written some other way.
+    XRPL_ASSERT(
+        (STAmount{asset, vault->at(sfAssetsAvailable)} == vault->at(sfAssetsAvailable)),
+        "xrpl::syncAssetsTotal : AssetsAvailable is a 16-digit STAmount value");
+
+    NumberRoundModeGuard const rg(Number::RoundingMode::Downward);
+    vault->at(sfAssetsTotal) = STAmount{asset, getAssetsTotal(vault)};
+}
+
+[[nodiscard]] bool
+debitIsNonZeroDust(SLE::ConstRef vault, Number const& amount)
+{
+    if (amount == 0)
+        return false;
+
+    auto const total = getVaultVersion(vault) == VaultVersion::FixedPrecision
+        ? vault->at(sfAssetsAvailable)
+        : getAssetsTotal(vault);
+    auto const asset = vault->at(sfAsset);
+    return STAmount{asset, total - amount} == STAmount{asset, total};
+}
+}  // namespace
+
+namespace detail {
+
+[[nodiscard]] int
+liveScale(Number const& reference, Asset const& asset, int baseScale)
+{
+    if (reference == beast::kZero)
+        return baseScale;
+    // Round Downward, not the ambient mode: the live exponent must match the
+    // exponent syncAssetsTotal actually stores (also Downward), regardless of
+    // what rounding mode the caller's own arithmetic is using.
+    NumberRoundModeGuard const rg(Number::RoundingMode::Downward);
+    return std::max(baseScale, scale(reference, asset));
+}
+
+[[nodiscard]] int
+posteriorAssetScale(
+    VaultVersion version,
+    Asset const& asset,
+    int baseScale,
+    Number const& reference,
+    Number const& delta)
+{
+    // ToNearest for the sum and for scale()'s canonicalization of it, as the
+    // Legacy/CashBasis clamp always did; liveScale sets its own mode.
+    NumberRoundModeGuard const rg(Number::RoundingMode::ToNearest);
+    Number const posterior = reference + delta;
+
+    switch (version)
+    {
+        case VaultVersion::Legacy:
+        case VaultVersion::CashBasis:
+            return scale(posterior, asset);
+        case VaultVersion::FixedPrecision:
+            return liveScale(posterior, asset, baseScale);
+    }
+    // LCOV_EXCL_START
+    UNREACHABLE("xrpl::detail::posteriorAssetScale : valid VaultVersion");
+    return Number::kMinExponent - 1;
+    // LCOV_EXCL_STOP
+}
+
+[[nodiscard]] STAmount
+creditToPosteriorScale(
+    Asset const& asset,
+    Number const& reference,
+    int baseScale,
+    Number const& raw,
+    Number::RoundingMode roundingMode)
+{
+    // Floor the SUM (reference + raw), not just raw. See
+    // creditToPosteriorAvailableScale's doc: a delta floored on its own grid
+    // can still leave a 17-digit sum once the reference has crossed a power
+    // of ten.
+    //
+    // Both reference + raw and flooredSum - reference can carry more digits
+    // than Number holds (the sum is on the posterior grid, the reference on
+    // the finer one). Compute both under roundingMode, not the caller's
+    // ambient mode, so the credit this returns never exceeds raw.
+    //
+    // Take the grid from this same sum. A sum just under a power of ten that
+    // rounds up to it in another mode would pick the coarser grid, and
+    // flooring the unrounded sum on it would land below reference.
+    NumberRoundModeGuard const rg(roundingMode);
+    Number const sum = reference + raw;
+    int const atScale = liveScale(sum, asset, baseScale);
+    Number const flooredSum = roundToAsset(asset, sum, atScale, roundingMode);
+    STAmount const credit{asset, flooredSum - reference};
+    XRPL_ASSERT_PARTS(
+        roundingMode != Number::RoundingMode::Downward ||
+            (credit >= beast::kZero && Number(credit) <= raw),
+        "xrpl::detail::creditToPosteriorScale",
+        "credit is between zero and raw");
+    return credit;
+}
+
+[[nodiscard]] int
+getPosteriorVaultScale(SLE::ConstRef vault, STAmount const& delta)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT,
+        "xrpl::detail::getPosteriorVaultScale : valid Vault sle");
+    XRPL_ASSERT(
+        delta.asset() == vault->at(sfAsset),
+        "xrpl::detail::getPosteriorVaultScale : delta and Vault asset match");
+    return posteriorScale(vault, getAssetsTotal(vault), delta);
+}
+
+}  // namespace detail
+
+[[nodiscard]] Number
+getAssetsTotal(SLE::ConstRef vault)
+{
+    XRPL_ASSERT(vault && vault->getType() == ltVAULT, "xrpl::getAssetsTotal : valid Vault sle");
+
+    if (getVaultVersion(vault) != VaultVersion::FixedPrecision)
+        return vault->at(sfAssetsTotal);
+
+    // AssetsAvailable is at -Scale (or coarser) and AssetsDeployed is always at
+    // -Scale, so the sum is exact while it fits 19 digits. Fix the mode so a
+    // sum that does not fit rounds the same way for every caller.
+    NumberRoundModeGuard const rg(Number::RoundingMode::Downward);
+    return vault->at(sfAssetsAvailable) + vault->at(sfAssetsDeployed);
+}
+
+[[nodiscard]] TER
+adjustVaultBalances(SLE::Ref vault, VaultBalanceChange const& change, beast::Journal j)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT, "xrpl::adjustVaultBalances : valid Vault sle");
+    XRPL_ASSERT(
+        getVaultVersion(vault) == VaultVersion::FixedPrecision,
+        "xrpl::adjustVaultBalances : FixedPrecision Vault");
+    Asset const asset = vault->at(sfAsset);
+    STAmount const cash = change.cash.value_or(STAmount{asset, 0});
+    XRPL_ASSERT(cash.asset() == asset, "xrpl::adjustVaultBalances : cash and Vault asset match");
+    // This is the mode the ledger's own transfers (trust line / MPT balance
+    // updates) normalize in; computing AA' with any other ambient mode would
+    // not reproduce what the real transfer just did to the backing balance.
+    XRPL_ASSERT(
+        Number::getround() == Number::RoundingMode::ToNearest,
+        "xrpl::adjustVaultBalances : ambient rounding mode is ToNearest");
+
+    // AA' is the exact trust-line/MPT arithmetic the ledger uses for the
+    // transfer itself: a Number sum re-canonicalized to the asset's 16-digit
+    // STAmount precision. MPT and XRP sums are already integral, so this is
+    // a no-op rounding for them.
+    //
+    // AssetsDeployed, LossUnrealized and YieldUnrealized move no cash, so they stay
+    // exact Number sums; the asserts below check each fits 16 digits, rather
+    // than letting an STAmount conversion round it silently.
+    STAmount const availableAfter{asset, Number(vault->at(sfAssetsAvailable)) + Number(cash)};
+    Number const assetsDeployedAfter = Number(vault->at(sfAssetsDeployed)) + change.deployed;
+    Number const lossUnrealizedAfter = Number(vault->at(sfLossUnrealized)) + change.loss;
+    // LoanSet, LoanPay and default each move YieldUnrealized by the change in
+    // the Loan's own TotalValueOutstanding - PrincipalOutstanding -
+    // ManagementFeeOutstanding, so it always equals that sum over the
+    // Vault's Loans and cannot go negative.
+    Number const yieldUnrealizedAfter = Number(vault->at(sfYieldUnrealized)) + change.yield;
+
+    if (availableAfter < beast::kZero || assetsDeployedAfter < beast::kZero ||
+        lossUnrealizedAfter < beast::kZero || yieldUnrealizedAfter < beast::kZero)
+    {
+        // LCOV_EXCL_START
+        JLOG(j.fatal()) << "adjustVaultBalances: a balance would become negative."
+                        << " AssetsAvailable: " << Number(availableAfter)
+                        << ", AssetsDeployed: " << assetsDeployedAfter
+                        << ", LossUnrealized: " << lossUnrealizedAfter
+                        << ", YieldUnrealized: " << yieldUnrealizedAfter;
+        return tefBAD_LEDGER;
+        // LCOV_EXCL_STOP
+    }
+
+    // The impairment rule: a Loan can only be impaired for as much as it
+    // still owes. Reachable only through LoanManage's impair.
+    if (lossUnrealizedAfter > assetsDeployedAfter)
+        return tecLIMIT_EXCEEDED;
+
+    // Every caller derives principal from a Loan's own PrincipalOutstanding so the new total must
+    // stay representable at the asset's own 16-digit precision too.
+    XRPL_ASSERT(
+        (STAmount{asset, assetsDeployedAfter} == assetsDeployedAfter),
+        "xrpl::adjustVaultBalances : AssetsDeployed is a 16-digit STAmount value");
+    XRPL_ASSERT(
+        (STAmount{asset, lossUnrealizedAfter} == lossUnrealizedAfter),
+        "xrpl::adjustVaultBalances : LossUnrealized is a 16-digit STAmount value");
+    XRPL_ASSERT(
+        (STAmount{asset, yieldUnrealizedAfter} == yieldUnrealizedAfter),
+        "xrpl::adjustVaultBalances : YieldUnrealized is a 16-digit STAmount value");
+
+    vault->at(sfAssetsAvailable) = availableAfter;
+    vault->at(sfAssetsDeployed) = assetsDeployedAfter;
+    vault->at(sfLossUnrealized) = lossUnrealizedAfter;
+    vault->at(sfYieldUnrealized) = yieldUnrealizedAfter;
+    syncAssetsTotal(vault);
+
+    return tesSUCCESS;
+}
+
+[[nodiscard]] TER
+adjustVaultCash(SLE::Ref vault, STAmount const& delta, beast::Journal j)
+{
+    if (getVaultVersion(vault) == VaultVersion::FixedPrecision)
+        return adjustVaultBalances(vault, {.cash = delta}, j);
+
+    vault->at(sfAssetsTotal) += delta;
+    vault->at(sfAssetsAvailable) += delta;
+    return tesSUCCESS;
+}
+
+[[nodiscard]] int
+getVaultScale(SLE::ConstRef vault)
+{
+    XRPL_ASSERT(vault && vault->getType() == ltVAULT, "xrpl::getVaultScale : valid Vault sle");
+
+    Number const assetsTotal = getAssetsTotal(vault);
+    switch (getVaultVersion(vault))
+    {
+        case VaultVersion::Legacy:
+        case VaultVersion::CashBasis:
+            return scale(assetsTotal, vault->at(sfAsset));
+        case VaultVersion::FixedPrecision:
+            return detail::liveScale(assetsTotal, vault->at(sfAsset), fixedBaseScale(vault));
+    }
+    // LCOV_EXCL_START
+    UNREACHABLE("xrpl::getVaultScale : valid VaultVersion");
+    return Number::kMinExponent - 1;
+    // LCOV_EXCL_STOP
+}
+
+[[nodiscard]] int
+getVaultBaseScale(SLE::ConstRef vault)
+{
+    XRPL_ASSERT(vault && vault->getType() == ltVAULT, "xrpl::getVaultBaseScale : valid Vault sle");
+
+    switch (getVaultVersion(vault))
+    {
+        case VaultVersion::Legacy:
+        case VaultVersion::CashBasis:
+            return getVaultScale(vault);
+        case VaultVersion::FixedPrecision:
+            return fixedBaseScale(vault);
+    }
+    // LCOV_EXCL_START
+    UNREACHABLE("xrpl::getVaultBaseScale : valid VaultVersion");
+    return Number::kMinExponent - 1;
+    // LCOV_EXCL_STOP
+}
+
+[[nodiscard]] STAmount
+roundToPosteriorVaultScale(
+    SLE::ConstRef vault,
+    STAmount const& amount,
+    Number::RoundingMode roundingMode)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT, "xrpl::roundToPosteriorVaultScale : valid Vault sle");
+    XRPL_ASSERT(
+        amount.asset() == vault->at(sfAsset),
+        "xrpl::roundToPosteriorVaultScale : amount and Vault asset match");
+    if (amount.integral())
+        return amount;
+    return roundToScale(amount, detail::getPosteriorVaultScale(vault, amount), roundingMode);
+}
+
+[[nodiscard]] STAmount
+creditToPosteriorAvailableScale(
+    SLE::ConstRef vault,
+    Number const& raw,
+    Number::RoundingMode roundingMode)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT,
+        "xrpl::creditToPosteriorAvailableScale : valid Vault sle");
+    Asset const asset = vault->at(sfAsset);
+    if (asset.integral())
+    {
+        NumberRoundModeGuard const rg(roundingMode);
+        return STAmount{asset, raw};
+    }
+
+    Number const reference = vault->at(sfAssetsAvailable);
+    return detail::creditToPosteriorScale(
+        asset, reference, fixedBaseScale(vault), raw, roundingMode);
+}
+
+[[nodiscard]] Number
+getVaultOpenLimit(SLE::ConstRef vault)
+{
+    XRPL_ASSERT(vault && vault->getType() == ltVAULT, "xrpl::getVaultOpenLimit : valid Vault sle");
+    XRPL_ASSERT(
+        getVaultVersion(vault) == VaultVersion::FixedPrecision,
+        "xrpl::getVaultOpenLimit : FixedPrecision Vault");
+    return Number{9, 15 + getVaultBaseScale(vault)};
+}
+
+[[nodiscard]] TER
+checkOptionalVaultInflow(SLE::ConstRef vault, STAmount const& amount)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT, "xrpl::checkOptionalVaultInflow : valid Vault sle");
+    XRPL_ASSERT(
+        amount.asset() == vault->at(sfAsset),
+        "xrpl::checkOptionalVaultInflow : amount and Vault asset match");
+    XRPL_ASSERT(!amount.negative(), "xrpl::checkOptionalVaultInflow : non-negative amount");
+    if (amount.negative())
+        return tefINTERNAL;  // LCOV_EXCL_LINE
+    if (getVaultVersion(vault) != VaultVersion::FixedPrecision)
+        return tesSUCCESS;
+
+    STAmount const rounded =
+        roundToPosteriorVaultScale(vault, amount, Number::RoundingMode::TowardsZero);
+    int const baseScale = getVaultBaseScale(vault);
+    // Keep this explicit even though a non-negative YieldUnrealized makes the
+    // Open-zone capacity ceiling reject every coarsening transition too. The
+    // protocol defines both conditions independently.
+    if (detail::getPosteriorVaultScale(vault, rounded) != baseScale)
+        return tecLIMIT_EXCEEDED;
+
+    if (vaultOpenZoneCapacity(vault, rounded) > getVaultOpenLimit(vault))
+        return tecLIMIT_EXCEEDED;
+    return tesSUCCESS;
+}
+
+[[nodiscard]] Number
+vaultOpenZoneCapacity(SLE::ConstRef vault, Number const& roundedAmount)
+{
+    XRPL_ASSERT(
+        vault && vault->getType() == ltVAULT, "xrpl::vaultOpenZoneCapacity : valid Vault sle");
+    XRPL_ASSERT(
+        getVaultVersion(vault) == VaultVersion::FixedPrecision,
+        "xrpl::vaultOpenZoneCapacity : FixedPrecision Vault");
+    NumberRoundModeGuard const rg(Number::RoundingMode::TowardsZero);
+    return getAssetsTotal(vault) + vault->at(sfYieldUnrealized) + roundedAmount;
+}
+
+[[nodiscard]] TER
+checkDebitNotDust(
+    SLE::ConstRef vault,
+    Number const& amount,
+    beast::Journal j,
+    std::string_view name)
+{
+    try
+    {
+        if (debitIsNonZeroDust(vault, amount))
+        {
+            JLOG(j.debug()) << name << ": amount too small to change stored vault balance";
+            return tecPRECISION_LOSS;
+        }
+    }
+    // LCOV_EXCL_START
+    catch (std::overflow_error const&)
+    {
+        // It's easy to hit this exception from Number with large enough Scale
+        // so we avoid spamming the log and only use debug here.
+        JLOG(j.debug())  //
+            << name << ": overflow error with"
+            << " scale=" << (int)vault->at(sfScale)  //
+            << ", assetsTotal=" << vault->at(sfAssetsTotal) << ", amount=" << amount;
+        return tecPATH_DRY;
+    }
+    // LCOV_EXCL_STOP
+    return tesSUCCESS;
+}
+
 [[nodiscard]] std::optional<STAmount>
 assetsToSharesDeposit(SLE::ConstRef vault, SLE::ConstRef issuance, STAmount const& assets)
 {
@@ -34,7 +505,7 @@ assetsToSharesDeposit(SLE::ConstRef vault, SLE::ConstRef issuance, STAmount cons
     if (assets.negative() || assets.asset() != vault->at(sfAsset))
         return std::nullopt;  // LCOV_EXCL_LINE
 
-    Number const assetTotal = vault->at(sfAssetsTotal);
+    Number const assetTotal = getAssetsTotal(vault);
     STAmount shares{vault->at(sfShareMPTID)};
     if (assetTotal == 0)
     {
@@ -58,7 +529,7 @@ sharesToAssetsDeposit(SLE::ConstRef vault, SLE::ConstRef issuance, STAmount cons
     if (shares.negative() || shares.asset() != vault->at(sfShareMPTID))
         return std::nullopt;  // LCOV_EXCL_LINE
 
-    Number const assetTotal = vault->at(sfAssetsTotal);
+    Number const assetTotal = getAssetsTotal(vault);
     STAmount assets{vault->at(sfAsset)};
     if (assetTotal == 0)
     {
@@ -85,37 +556,52 @@ clampToAssetsTotalScale(SLE::ConstRef vault, STAmount const& delta)
     {
         return magnitude;
     }
-    Number const assetsTotal = vault->at(sfAssetsTotal);
-
-    // Calculate the scale after applying the delta using ToNearest rounding.
-    // This aligns the delta with scale checks used by vault invariants.
-    int const postScale = [&] {
-        NumberRoundModeGuard const rg(Number::RoundingMode::ToNearest);
-        return scale(assetsTotal + delta, asset);
-    }();
 
     STAmount actualDelta;
-    if (delta.negative())
+    if (getVaultVersion(vault) == VaultVersion::FixedPrecision)
     {
-        // For withdrawals (debits), floor the magnitude to the target scale
-        // to ensure exact grid alignment without paying out extra assets.
-        actualDelta = roundToScale(magnitude, postScale, Number::RoundingMode::Downward);
+        // FixedPrecision only reaches this branch for credits (VaultDeposit);
+        // outflows go through clampVaultOutflow -> clampToAvailableScale,
+        // which rounds at AssetsAvailable's own posterior scale instead.
+        XRPL_ASSERT(
+            !delta.negative(), "xrpl::clampToAssetsTotalScale : FixedPrecision credit only");
+        STAmount const rounded =
+            roundToPosteriorVaultScale(vault, delta, Number::RoundingMode::TowardsZero);
+        actualDelta = rounded.negative() ? -rounded : rounded;
     }
     else
     {
-        // For deposits (credits), derive actualDelta from the floored posterior total.
-        // This prevents grid alignment issues from crediting the vault more than deposited.
-        //
-        // Sum using Downward rounding so intermediate precision doesn't round up
-        // and exceed the original requested amount.
-        Number const posterior = [&] {
-            NumberRoundModeGuard const rg(Number::RoundingMode::Downward);
-            return assetsTotal + magnitude;
+        Number const assetsTotal = getAssetsTotal(vault);
+
+        // Calculate the scale after applying the delta using ToNearest rounding.
+        // This aligns the delta with scale checks used by vault invariants.
+        int const postScale = [&] {
+            NumberRoundModeGuard const rg(Number::RoundingMode::ToNearest);
+            return scale(assetsTotal + delta, asset);
         }();
 
-        Number const roundedPosterior =
-            roundToAsset(asset, posterior, postScale, Number::RoundingMode::Downward);
-        actualDelta = STAmount{asset, roundedPosterior - assetsTotal};
+        if (delta.negative())
+        {
+            // For withdrawals (debits), floor the magnitude to the target scale
+            // to ensure exact grid alignment without paying out extra assets.
+            actualDelta = roundToScale(magnitude, postScale, Number::RoundingMode::Downward);
+        }
+        else
+        {
+            // For deposits (credits), derive actualDelta from the floored posterior total.
+            // This prevents grid alignment issues from crediting the vault more than deposited.
+            //
+            // Sum using Downward rounding so intermediate precision doesn't round up
+            // and exceed the original requested amount.
+            Number const posterior = [&] {
+                NumberRoundModeGuard const rg(Number::RoundingMode::Downward);
+                return assetsTotal + magnitude;
+            }();
+
+            Number const roundedPosterior =
+                roundToAsset(asset, posterior, postScale, Number::RoundingMode::Downward);
+            actualDelta = STAmount{asset, roundedPosterior - assetsTotal};
+        }
     }
 
     XRPL_ASSERT(
@@ -130,21 +616,47 @@ clampToAssetsTotalScale(SLE::ConstRef vault, STAmount const& delta)
     return actualDelta;
 }
 
-[[nodiscard]] Number
-assetsTotalForWithdrawal(SLE::ConstRef vault, WaiveUnrealizedLoss waive)
+[[nodiscard]] std::expected<STAmount, TER>
+clampVaultOutflow(SLE::ConstRef vault, STAmount const& delta)
 {
-    Number assetTotal = vault->at(sfAssetsTotal);
-    if (waive == WaiveUnrealizedLoss::No)
-        assetTotal -= vault->at(sfLossUnrealized);
-    return assetTotal;
+    XRPL_ASSERT(delta.negative(), "xrpl::clampVaultOutflow : outflow delta is negative");
+    return getVaultVersion(vault) == VaultVersion::FixedPrecision
+        ? clampToAvailableScale(vault, delta)
+        : clampToAssetsTotalScale(vault, delta);
+}
+
+[[nodiscard]] int
+vaultBaseScale(Asset const& asset, std::uint8_t scale)
+{
+    if (asset.integral())
+        return 0;
+    return -static_cast<int>(scale);
 }
 
 [[nodiscard]] bool
-debitIsNonZeroDust(Asset const& asset, Number const& total, Number const& amount)
+isOnVaultBaseGrid(Asset const& asset, Number const& value, int baseScale)
 {
-    if (amount == 0)
-        return false;
-    return STAmount{asset, total - amount} == STAmount{asset, total};
+    // isRepresentable first: building an STAmount from an out-of-range value
+    // throws, and this checks user-supplied values in preclaim.
+    return isRepresentable(asset, value) && STAmount{asset, value} == value &&
+        roundToAsset(asset, value, baseScale, Number::RoundingMode::TowardsZero) == value;
+}
+
+[[nodiscard]] TER
+checkAssetsMaximum(SLE::ConstRef vault, Number const& amount)
+{
+    return isOnVaultBaseGrid(vault->at(sfAsset), amount, getVaultBaseScale(vault))
+        ? TER{tesSUCCESS}
+        : TER{tecPRECISION_LOSS};
+}
+
+[[nodiscard]] Number
+assetsTotalForWithdrawal(SLE::ConstRef vault, WaiveUnrealizedLoss waive)
+{
+    Number assetTotal = getAssetsTotal(vault);
+    if (waive == WaiveUnrealizedLoss::No)
+        assetTotal -= vault->at(sfLossUnrealized);
+    return assetTotal;
 }
 
 [[nodiscard]] std::optional<STAmount>
@@ -218,34 +730,40 @@ isSoleShareholder(ReadView const& view, AccountID const& account, SLE::ConstRef
 }
 
 [[nodiscard]] VaultVersion
-getVaultVersion(SLE::ConstRef vault)
+decodeVaultVersion(std::optional<std::uint8_t> leVersion)
 {
-    XRPL_ASSERT(vault && vault->getType() == ltVAULT, "xrpl::getVaultVersion : valid Vault sle");
-    if (!vault->isFieldPresent(sfLEVersion))
+    if (!leVersion)
         return VaultVersion::Legacy;
-
-    auto const version = vault->at(sfLEVersion);
-    if (version > std::to_underlying(VaultVersion::CashBasis))
+    if (*leVersion > std::to_underlying(VaultVersion::FixedPrecision))
     {
         // LCOV_EXCL_START
-        UNREACHABLE("xrpl::getVaultVersion : invalid vault version");
+        UNREACHABLE("xrpl::decodeVaultVersion : invalid vault version");
         return VaultVersion::Legacy;
         // LCOV_EXCL_STOP
     }
-    return static_cast<VaultVersion>(version);
+    return static_cast<VaultVersion>(*leVersion);
 }
 
-namespace {
-
-[[nodiscard]] VaultKind
-decodeVaultKind(std::optional<std::uint8_t> vaultKind)
+[[nodiscard]] VaultVersion
+getVaultVersion(SLE::ConstRef vault)
 {
-    if (vaultKind && *vaultKind == std::to_underlying(VaultKind::ClosedEnded))
-        return VaultKind::ClosedEnded;
-    return VaultKind::OpenEnded;
+    XRPL_ASSERT(vault && vault->getType() == ltVAULT, "xrpl::getVaultVersion : valid Vault sle");
+    return decodeVaultVersion(vault->at(~sfLEVersion));
 }
 
-}  // namespace
+[[nodiscard]] VaultVersion
+getVaultDefaultVersion(Rules const& rules)
+{
+    // FixedPrecision requires featureLendingProtocolV1_1 (closed-ended Vaults and
+    // cash-basis accounting) and fixCleanup3_4_0, so a FixedPrecision Vault always
+    // sees both enabled. fixCleanup3_2_0 is already enabled on the network.
+    if (rules.enabled(featureLendingProtocolV1_1) && rules.enabled(featureLendingProtocolV1_2) &&
+        rules.enabled(fixCleanup3_4_0))
+        return VaultVersion::FixedPrecision;
+    if (rules.enabled(featureLendingProtocolV1_1))
+        return VaultVersion::CashBasis;
+    return VaultVersion::Legacy;
+}
 
 [[nodiscard]] VaultKind
 getVaultKind(SLE::ConstRef vault)

src/libxrpl/protocol/ConfidentialTransfer.cpp

@@ -435,18 +435,25 @@ areMirrorsCurrent(SLE const& issuance, SLE const& mptoken)
 }
 
 void
-setIssuerMirrorEpoch(SLE const& issuance, SLE& mptoken)
+setIssuerMirrorCurrent(SLE const& issuance, SLE& mptoken)
 {
     XRPL_ASSERT(
         issuance.getType() == ltMPTOKEN_ISSUANCE,
-        "xrpl::setIssuerMirrorEpoch : issuance MPTokenIssuance object");
+        "xrpl::setIssuerMirrorCurrent : issuance MPTokenIssuance object");
     XRPL_ASSERT(
-        mptoken.getType() == ltMPTOKEN, "xrpl::setIssuerMirrorEpoch : mptoken MPToken object");
+        mptoken.getType() == ltMPTOKEN, "xrpl::setIssuerMirrorCurrent : mptoken MPToken object");
 
     // Unlike the auditor mirror, the issuer mirror is not optional: every
     // confidential MPToken carries one, so there is no existence check here.
+    //
+    // Record the key and epoch under which the mirror is now encrypted. Both fields remain absent
+    // at epoch 0: such mirrors use the original issuer key. The original key is stored in
+    // sfInitialIssuerEncryptionKey after the first rotation.
     if (auto const epoch = issuance[~sfIssuerKeyEpoch].value_or(0); epoch != 0)
+    {
         mptoken[sfIssuerKeyMirrorEpoch] = epoch;
+        mptoken[sfIssuerMirrorEncryptionKey] = issuance[sfIssuerEncryptionKey];
+    }
 }
 
 void
@@ -466,9 +473,9 @@ setAuditorMirrorEpoch(SLE const& issuance, SLE& mptoken)
 }
 
 void
-setMirrorEpochs(SLE const& issuance, SLE& mptoken)
+setMirrorsCurrent(SLE const& issuance, SLE& mptoken)
 {
-    setIssuerMirrorEpoch(issuance, mptoken);
+    setIssuerMirrorCurrent(issuance, mptoken);
     setAuditorMirrorEpoch(issuance, mptoken);
 }
 

src/libxrpl/protocol/ErrorCodes.cpp

@@ -20,92 +20,88 @@ namespace detail {
 // will remain in the object file.  But the string literals will remain.
 //
 // There's a certain amount of tension in determining the correct HTTP
-// status to associate with a given RPC error.  Every row below names its
-// HTTP status, and a row that omits it does not compile, since ErrorInfo has
-// no constructor that leaves the status out.
+// status to associate with a given RPC error.  Initially all RPC errors
+// returned 200 (OK).  And that's the default behavior if no HTTP status code
+// is specified below.
 //
 // The codes currently selected target the load balancer fail-over use case.
 // If a query fails on one node but is likely to have a positive outcome
 // on a different node, then the failure should return a 4xx/5xx range
 // status code.
 
-// The rows below are aligned by hand into four columns, so that a wrong status or a mistyped token
-// is visible by scanning one column. That cannot be had inside the 100-column limit once the
-// longest enumerator and the longest message sit in one row. So this region is exempt from the
-// limit by design rather than by oversight.
 // clang-format off
 static constexpr ErrorInfo kUnorderedErrorInfos[]{
-    {RpcActMalformed,                             "actMalformed",                             "Account malformed.",                                                  400},
-    {RpcActNotFound,                              "actNotFound",                              "Account not found.",                                                  404},
-    {RpcAlreadyMultisig,                          "alreadyMultisig",                          "Already multisigned.",                                                400},
-    {RpcAlreadySingleSig,                         "alreadySingleSig",                         "Already single-signed.",                                              400},
-    {RpcAmendmentBlocked,                         "amendmentBlocked",                         "Amendment blocked, need upgrade.",                                    503},
-    {RpcExpiredValidatorList,                     "unlBlocked",                               "Validator list expired.",                                             503},
-    {RpcAtxDeprecated,                            "deprecated",                               "Use the new API or specify a ledger range.",                          400},
-    {RpcBadKeyType,                               "badKeyType",                               "Bad key type.",                                                       400},
-    {RpcBadFeature,                               "badFeature",                               "Feature unknown or invalid.",                                         500},
-    {RpcBadIssuer,                                "badIssuer",                                "Issuer account malformed.",                                           400},
-    {RpcBadMarket,                                "badMarket",                                "No such market.",                                                     404},
-    {RpcBadSecret,                                "badSecret",                                "Secret does not match account.",                                      403},
-    {RpcBadSeed,                                  "badSeed",                                  "Disallowed seed.",                                                    403},
-    {RpcBadSyntax,                                "badSyntax",                                "Syntax error.",                                                       400},
-    {RpcChannelMalformed,                         "channelMalformed",                         "Payment channel is malformed.",                                       400},
-    {RpcChannelAmtMalformed,                      "channelAmtMalformed",                      "Payment channel amount is malformed.",                                400},
-    {RpcCommandMissing,                           "commandMissing",                           "Missing command entry.",                                              400},
-    {RpcDbDeserialization,                        "dbDeserialization",                        "Database deserialization error.",                                     502},
-    {RpcDstActMalformed,                          "dstActMalformed",                          "Destination account is malformed.",                                   400},
-    {RpcDstActMissing,                            "dstActMissing",                            "Destination account not provided.",                                   400},
-    {RpcDstActNotFound,                           "dstActNotFound",                           "Destination account not found.",                                      404},
-    {RpcDstAmtMalformed,                          "dstAmtMalformed",                          "Destination amount/currency/issuer is malformed.",                    400},
-    {RpcDstAmtMissing,                            "dstAmtMissing",                            "Destination amount/currency/issuer is missing.",                      400},
-    {RpcDstIsrMalformed,                          "dstIsrMalformed",                          "Destination issuer is malformed.",                                    400},
-    {RpcExcessiveLgrRange,                        "excessiveLgrRange",                        "Ledger range exceeds 1000.",                                          400},
-    {RpcForbidden,                                "forbidden",                                "Bad credentials.",                                                    403},
-    {RpcHighFee,                                  "highFee",                                  "Current transaction fee exceeds your limit.",                         402},
-    {RpcInternal,                                 "internal",                                 "Internal error.",                                                     500},
-    {RpcInvalidLgrRange,                          "invalidLgrRange",                          "Ledger range is invalid.",                                            400},
-    {RpcInvalidParams,                            "invalidParams",                            "Invalid parameters.",                                                 400},
-    {RpcInvalidHotwallet,                         "invalidHotWallet",                         "Invalid hotwallet.",                                                  400},
-    {RpcIssueMalformed,                           "issueMalformed",                           "Issue is malformed.",                                                 400},
-    {RpcJsonRpc,                                  "json_rpc",                                 "JSON-RPC transport error.",                                           500},
-    {RpcLgrIdxsInvalid,                           "lgrIdxsInvalid",                           "Ledger indexes invalid.",                                             400},
-    {RpcLgrIdxMalformed,                          "lgrIdxMalformed",                          "Ledger index malformed.",                                             400},
-    {RpcLgrNotFound,                              "lgrNotFound",                              "Ledger not found.",                                                   404},
-    {RpcLgrNotValidated,                          "lgrNotValidated",                          "Ledger not validated.",                                               202},
-    {RpcMasterDisabled,                           "masterDisabled",                           "Master key is disabled.",                                             403},
-    {RpcNotEnabled,                               "notEnabled",                               "Not enabled in configuration.",                                       501},
-    {RpcNotImpl,                                  "notImpl",                                  "Not implemented.",                                                    501},
-    {RpcNotReady,                                 "notReady",                                 "Not ready to handle this request.",                                   503},
-    {RpcNotSupported,                             "notSupported",                             "Operation not supported.",                                            501},
-    {RpcNoClosed,                                 "noClosed",                                 "Closed ledger is unavailable.",                                       503},
-    {RpcNoCurrent,                                "noCurrent",                                "Current ledger is unavailable.",                                      503},
-    {RpcNotSynced,                                "notSynced",                                "Not synced to the network.",                                          503},
-    {RpcNoEvents,                                 "noEvents",                                 "Current transport does not support events.",                          405},
-    {RpcNoNetwork,                                "noNetwork",                                "Not synced to the network.",                                          503},
-    {RpcWrongNetwork,                             "wrongNetwork",                             "Wrong network.",                                                      503},
-    {RpcNoPermission,                             "noPermission",                             "You don't have permission for this command.",                         401},
-    {RpcNoPfRequest,                              "noPathRequest",                            "No pathfinding request in progress.",                                 404},
-    {RpcObjectNotFound,                           "objectNotFound",                           "The requested object was not found.",                                 404},
-    {RpcPublicMalformed,                          "publicMalformed",                          "Public key is malformed.",                                            400},
-    {RpcSendmaxMalformed,                         "sendMaxMalformed",                         "SendMax amount malformed.",                                           400},
-    {RpcSigningMalformed,                         "signingMalformed",                         "Signing of transaction is malformed.",                                400},
-    {RpcSlowDown,                                 "slowDown",                                 "You are placing too much load on the server.",                        429},
-    {RpcSrcActMalformed,                          "srcActMalformed",                          "Source account is malformed.",                                        400},
-    {RpcSrcActMissing,                            "srcActMissing",                            "Source account not provided.",                                        400},
-    {RpcSrcActNotFound,                           "srcActNotFound",                           "Source account not found.",                                           404},
-    {RpcDelegateActNotFound,                      "delegateActNotFound",                      "Delegate account not found.",                                         404},
-    {RpcSrcCurMalformed,                          "srcCurMalformed",                          "Source currency is malformed.",                                       400},
-    {RpcSrcIsrMalformed,                          "srcIsrMalformed",                          "Source issuer is malformed.",                                         400},
-    {RpcStreamMalformed,                          "malformedStream",                          "Stream malformed.",                                                   400},
-    {RpcTooBusy,                                  "tooBusy",                                  "The server is too busy to help you now.",                             503},
-    {RpcTxnNotFound,                              "txnNotFound",                              "Transaction not found.",                                              404},
-    {RpcUnknownCommand,                           "unknownCmd",                               "Unknown method.",                                                     405},
-    {RpcOracleMalformed,                          "oracleMalformed",                          "Oracle request is malformed.",                                        400},
-    {RpcBadCredentials,                           "badCredentials",                           "Credentials do not exist, are not accepted, or have expired.",        400},
-    {RpcTxSigned,                                 "transactionSigned",                        "Transaction should not be signed.",                                   400},
-    {RpcDomainMalformed,                          "domainMalformed",                          "Domain is malformed.",                                                400},
-    {RpcEntryNotFound,                            "entryNotFound",                            "Entry not found.",                                                    400},
-    {RpcUnexpectedLedgerType,                     "unexpectedLedgerType",                     "Unexpected ledger type.",                                             400},
+    {RpcActMalformed,          "actMalformed",         "Account malformed."},
+    {RpcActNotFound,          "actNotFound",          "Account not found."},
+    {RpcAlreadyMultisig,       "alreadyMultisig",      "Already multisigned."},
+    {RpcAlreadySingleSig,     "alreadySingleSig",     "Already single-signed."},
+    {RpcAmendmentBlocked,      "amendmentBlocked",     "Amendment blocked, need upgrade.", 503},
+    {RpcExpiredValidatorList, "unlBlocked",           "Validator list expired.", 503},
+    {RpcAtxDeprecated,         "deprecated",           "Use the new API or specify a ledger range.", 400},
+    {RpcBadKeyType,           "badKeyType",           "Bad key type.", 400},
+    {RpcBadFeature,            "badFeature",           "Feature unknown or invalid.", 500},
+    {RpcBadIssuer,             "badIssuer",            "Issuer account malformed.", 400},
+    {RpcBadMarket,             "badMarket",            "No such market.", 404},
+    {RpcBadSecret,             "badSecret",            "Secret does not match account.", 403},
+    {RpcBadSeed,               "badSeed",              "Disallowed seed.", 403},
+    {RpcBadSyntax,             "badSyntax",            "Syntax error.", 400},
+    {RpcChannelMalformed,      "channelMalformed",     "Payment channel is malformed.", 400},
+    {RpcChannelAmtMalformed,  "channelAmtMalformed",  "Payment channel amount is malformed.", 400},
+    {RpcCommandMissing,        "commandMissing",       "Missing command entry.", 400},
+    {RpcDbDeserialization,     "dbDeserialization",    "Database deserialization error.", 502},
+    {RpcDstActMalformed,      "dstActMalformed",      "Destination account is malformed.", 400},
+    {RpcDstActMissing,        "dstActMissing",        "Destination account not provided.", 400},
+    {RpcDstActNotFound,      "dstActNotFound",       "Destination account not found.", 404},
+    {RpcDstAmtMalformed,      "dstAmtMalformed",      "Destination amount/currency/issuer is malformed.", 400},
+    {RpcDstAmtMissing,        "dstAmtMissing",        "Destination amount/currency/issuer is missing.", 400},
+    {RpcDstIsrMalformed,      "dstIsrMalformed",      "Destination issuer is malformed.", 400},
+    {RpcExcessiveLgrRange,    "excessiveLgrRange",    "Ledger range exceeds 1000.", 400},
+    {RpcForbidden,              "forbidden",            "Bad credentials.", 403},
+    {RpcHighFee,               "highFee",              "Current transaction fee exceeds your limit.", 402},
+    {RpcInternal,               "internal",             "Internal error.", 500},
+    {RpcInvalidLgrRange,      "invalidLgrRange",      "Ledger range is invalid.", 400},
+    {RpcInvalidParams,         "invalidParams",        "Invalid parameters.", 400},
+    {RpcInvalidHotwallet,      "invalidHotWallet",     "Invalid hotwallet.", 400},
+    {RpcIssueMalformed,        "issueMalformed",       "Issue is malformed.", 400},
+    {RpcJsonRpc,               "json_rpc",             "JSON-RPC transport error.", 500},
+    {RpcLgrIdxsInvalid,       "lgrIdxsInvalid",       "Ledger indexes invalid.", 400},
+    {RpcLgrIdxMalformed,      "lgrIdxMalformed",      "Ledger index malformed.", 400},
+    {RpcLgrNotFound,          "lgrNotFound",          "Ledger not found.", 404},
+    {RpcLgrNotValidated,      "lgrNotValidated",      "Ledger not validated.", 202},
+    {RpcMasterDisabled,        "masterDisabled",       "Master key is disabled.", 403},
+    {RpcNotEnabled,            "notEnabled",           "Not enabled in configuration.", 501},
+    {RpcNotImpl,               "notImpl",              "Not implemented.", 501},
+    {RpcNotReady,              "notReady",             "Not ready to handle this request.", 503},
+    {RpcNotSupported,          "notSupported",         "Operation not supported.", 501},
+    {RpcNoClosed,              "noClosed",             "Closed ledger is unavailable.", 503},
+    {RpcNoCurrent,             "noCurrent",            "Current ledger is unavailable.", 503},
+    {RpcNotSynced,             "notSynced",            "Not synced to the network.", 503},
+    {RpcNoEvents,              "noEvents",             "Current transport does not support events.", 405},
+    {RpcNoNetwork,             "noNetwork",            "Not synced to the network.", 503},
+    {RpcWrongNetwork,          "wrongNetwork",         "Wrong network.", 503},
+    {RpcNoPermission,          "noPermission",         "You don't have permission for this command.", 401},
+    {RpcNoPfRequest,          "noPathRequest",        "No pathfinding request in progress.", 404},
+    {RpcObjectNotFound,       "objectNotFound",       "The requested object was not found.", 404},
+    {RpcPublicMalformed,       "publicMalformed",      "Public key is malformed.", 400},
+    {RpcSendmaxMalformed,      "sendMaxMalformed",     "SendMax amount malformed.", 400},
+    {RpcSigningMalformed,      "signingMalformed",     "Signing of transaction is malformed.", 400},
+    {RpcSlowDown,              "slowDown",             "You are placing too much load on the server.", 429},
+    {RpcSrcActMalformed,      "srcActMalformed",      "Source account is malformed.", 400},
+    {RpcSrcActMissing,        "srcActMissing",        "Source account not provided.", 400},
+    {RpcSrcActNotFound,      "srcActNotFound",       "Source account not found.", 404},
+    {RpcDelegateActNotFound, "delegateActNotFound",  "Delegate account not found.", 404},
+    {RpcSrcCurMalformed,      "srcCurMalformed",      "Source currency is malformed.", 400},
+    {RpcSrcIsrMalformed,      "srcIsrMalformed",      "Source issuer is malformed.", 400},
+    {RpcStreamMalformed,       "malformedStream",      "Stream malformed.", 400},
+    {RpcTooBusy,               "tooBusy",              "The server is too busy to help you now.", 503},
+    {RpcTxnNotFound,          "txnNotFound",          "Transaction not found.", 404},
+    {RpcUnknownCommand,        "unknownCmd",           "Unknown method.", 405},
+    {RpcOracleMalformed,       "oracleMalformed",      "Oracle request is malformed.", 400},
+    {RpcBadCredentials,        "badCredentials",       "Credentials do not exist, are not accepted, or have expired.", 400},
+    {RpcTxSigned,              "transactionSigned",    "Transaction should not be signed.", 400},
+    {RpcDomainMalformed,       "domainMalformed",      "Domain is malformed.", 400},
+    {RpcEntryNotFound,        "entryNotFound",        "Entry not found.", 400},
+    {RpcUnexpectedLedgerType, "unexpectedLedgerType", "Unexpected ledger type.", 400},
 };
 // clang-format on
 

src/libxrpl/protocol/MPTAmount.cpp

@@ -1,10 +1,24 @@
 #include <xrpl/protocol/MPTAmount.h>
 
+#include <xrpl/basics/MathUtilities.h>
+#include <xrpl/basics/contract.h>
+#include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/Rules.h>
+
+#include <stdexcept>
+
 namespace xrpl {
 
 MPTAmount&
 MPTAmount::operator+=(MPTAmount const& other)
 {
+    if (auto const result = checkedAdd(value_, other.value()))
+    {
+        value_ = *result;
+        return *this;
+    }
+    if (isFeatureEnabled(fixCleanup3_5_0, /*resultIfNoRules*/ true))
+        Throw<std::overflow_error>("MPTAmount::operator+= overflow");
     value_ += other.value();
     return *this;
 }
@@ -12,6 +26,13 @@ MPTAmount::operator+=(MPTAmount const& other)
 MPTAmount&
 MPTAmount::operator-=(MPTAmount const& other)
 {
+    if (auto const result = checkedSub(value_, other.value()))
+    {
+        value_ = *result;
+        return *this;
+    }
+    if (isFeatureEnabled(fixCleanup3_5_0, /*resultIfNoRules*/ true))
+        Throw<std::overflow_error>("MPTAmount::operator-= overflow");
     value_ -= other.value();
     return *this;
 }

src/libxrpl/protocol/Quality.cpp

@@ -3,10 +3,14 @@
 #include <xrpl/beast/utility/Zero.h>  // IWYU pragma: keep
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/protocol/Asset.h>
+#include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/Rules.h>
 #include <xrpl/protocol/STAmount.h>
 
 #include <cstdint>
 #include <limits>  // IWYU pragma: keep
+#include <optional>
+#include <stdexcept>
 
 namespace xrpl {
 
@@ -81,13 +85,46 @@ Quality::ceilInStrict(Amounts const& amount, STAmount const& limit, bool roundUp
     return ceilInImpl<divRoundStrict>(amount, limit, roundUp, *this);
 }
 
+// Returns std::nullopt if a native result can't be represented, instead of
+// throwing. Pathfinding runs without transaction
+// rules, so default to the fixed behavior there to match transactions once the
+// amendment is enabled.
+template <STAmount (*MulRoundFunc)(STAmount const&, STAmount const&, Asset const&, bool)>
+static std::optional<STAmount>
+tryMulRound(STAmount const& v1, STAmount const& v2, Asset const& asset, bool roundUp)
+{
+    try
+    {
+        return MulRoundFunc(v1, v2, asset, roundUp);
+    }
+    catch (std::overflow_error const&)
+    {
+        // std::overflow_error is a std::runtime_error, so it must be caught
+        // first to keep the handler below from swallowing it. It means the
+        // computation itself overflowed, not that the result is out of range.
+        // Callers handle it, e.g. BookStep removes the offer.
+        throw;
+    }
+    catch (std::runtime_error const&)
+    {
+        if (!asset.native() || !isFeatureEnabled(fixCleanup3_5_0, /*resultIfNoRules*/ true))
+            throw;
+        return std::nullopt;
+    }
+}
+
 template <STAmount (*MulRoundFunc)(STAmount const&, STAmount const&, Asset const&, bool)>
 static Amounts
 ceilOutImpl(Amounts const& amount, STAmount const& limit, bool roundUp, Quality const& quality)
 {
     if (amount.out > limit)
     {
-        Amounts result(MulRoundFunc(limit, quality.rate(), amount.in.asset(), roundUp), limit);
+        // An unrepresentable XRP product is larger than amount.in, so the
+        // clamp below would return amount.in anyway.
+        Amounts result(
+            tryMulRound<MulRoundFunc>(limit, quality.rate(), amount.in.asset(), roundUp)
+                .value_or(amount.in),
+            limit);
         // Clamp in
         if (result.in > amount.in)
             result.in = amount.in;

src/libxrpl/protocol/STAmount.cpp

@@ -1,6 +1,7 @@
 #include <xrpl/protocol/STAmount.h>
 
 #include <xrpl/basics/Log.h>
+#include <xrpl/basics/MathUtilities.h>
 #include <xrpl/basics/Number.h>
 #include <xrpl/basics/contract.h>
 #include <xrpl/basics/safe_cast.h>
@@ -384,10 +385,11 @@ operator+(STAmount const& v1, STAmount const& v2)
         return {v1.getFName(), v1.asset(), v2.mantissa(), v2.exponent(), v2.negative()};
     }
 
+    // XRPAmount and MPTAmount check for int64 overflow under fixCleanup3_5_0.
     if (v1.native())
-        return {v1.getFName(), getSNValue(v1) + getSNValue(v2)};
+        return {v1.getFName(), (v1.xrp() + v2.xrp()).drops()};
     if (v1.holds<MPTIssue>())
-        return {v1.asset_, v1.mpt().value() + v2.mpt().value()};
+        return {v1.asset_, (v1.mpt() + v2.mpt()).value()};
 
     auto x = v1;
     x = v1.iou() + v2.iou();
@@ -443,6 +445,22 @@ getRate(STAmount const& offerOut, STAmount const& offerIn)
     }
 }
 
+bool
+isRepresentable(Asset const& asset, Number const& value)
+{
+    try
+    {
+        // Out-of-range values throw std::overflow_error from Number or
+        // IOUAmount, or std::runtime_error from STAmount::canonicalize.
+        [[maybe_unused]] STAmount const amount{asset, value};
+        return true;
+    }
+    catch (std::runtime_error const&)
+    {
+        return false;
+    }
+}
+
 /**
  * @brief Safely checks if two STAmount values can be added without overflow,
  * underflow, or precision loss.
@@ -474,16 +492,7 @@ canAdd(STAmount const& a, STAmount const& b)
 
     // XRP case (overflow & underflow check)
     if (isXRP(a) && isXRP(b))
-    {
-        XRPAmount const aVal = a.xrp();
-        XRPAmount const bVal = b.xrp();
-
-        return !(
-            (bVal > XRPAmount{0} &&
-             aVal > XRPAmount{std::numeric_limits<XRPAmount::value_type>::max()} - bVal) ||
-            (bVal < XRPAmount{0} &&
-             aVal < XRPAmount{std::numeric_limits<XRPAmount::value_type>::min()} - bVal));
-    }
+        return checkedAdd(a.xrp().drops(), b.xrp().drops()).has_value();
 
     // IOU case (precision check)
     auto const ret = std::visit(
@@ -500,15 +509,7 @@ canAdd(STAmount const& a, STAmount const& b)
 
             // MPT (overflow & underflow check)
             if constexpr (kIsMptissueV<TIss1> && kIsMptissueV<TIss2>)
-            {
-                MPTAmount const aVal = a.mpt();
-                MPTAmount const bVal = b.mpt();
-                return !(
-                    (bVal > MPTAmount{0} &&
-                     aVal > MPTAmount{std::numeric_limits<MPTAmount::value_type>::max()} - bVal) ||
-                    (bVal < MPTAmount{0} &&
-                     aVal < MPTAmount{std::numeric_limits<MPTAmount::value_type>::min()} - bVal));
-            }
+                return checkedAdd(a.mpt().value(), b.mpt().value()).has_value();
             return std::nullopt;
         },
         a.asset().value(),
@@ -559,11 +560,7 @@ canSubtract(STAmount const& a, STAmount const& b)
             return false;
 
         // Check for overflow
-        if (bVal < XRPAmount{0} &&
-            aVal > XRPAmount{std::numeric_limits<XRPAmount::value_type>::max()} + bVal)
-            return false;
-
-        return true;
+        return checkedSub(aVal.drops(), bVal.drops()).has_value();
     }
 
     // IOU case (no underflow)
@@ -586,10 +583,7 @@ canSubtract(STAmount const& a, STAmount const& b)
                     return false;
 
                 // Overflow check
-                if (bVal < MPTAmount{0} &&
-                    aVal > MPTAmount{std::numeric_limits<MPTAmount::value_type>::max()} + bVal)
-                    return false;
-                return true;
+                return checkedSub(aVal.value(), bVal.value()).has_value();
             }
             return std::nullopt;
         },
@@ -1231,6 +1225,19 @@ divide(STAmount const& num, STAmount const& den, Asset const& asset)
     if (num == beast::kZero)
         return {asset};
 
+    // The legacy path below assumes 16-digit mantissas. An MPT mantissa is
+    // the raw 63-bit value and is never scaled down, so an MPT numerator can
+    // overflow the quotient and an MPT denominator shortens it, moving the +5
+    // nudge into a significant digit. Use Number arithmetic under
+    // MPTokensV2 whenever an MPT is involved, as mulRound/divRound do. Pin
+    // the rounding mode so the result does not depend on the caller's.
+    if (isFeatureEnabled(featureMPTokensV2, /*resultIfNoRules*/ true) &&
+        (asset.holds<MPTIssue>() || num.holds<MPTIssue>() || den.holds<MPTIssue>()))
+    {
+        NumberRoundModeGuard const rg(Number::RoundingMode::ToNearest);
+        return STAmount{asset, Number{num} / Number{den}};
+    }
+
     std::uint64_t numVal = num.mantissa();
     std::uint64_t denVal = den.mantissa();
     int numOffset = num.exponent();
@@ -1260,11 +1267,21 @@ divide(STAmount const& num, STAmount const& den, Asset const& asset)
     // numerator by 10^17 (the product is in the range of
     // 10^32 to 10^33) followed by a division, so the result
     // is in the range of 10^16 to 10^15.
-    return STAmount(
-        asset,
-        muldiv(numVal, kTenTO17, denVal) + 5,
-        numOffset - denOffset - 17,
-        num.negative() != den.negative());
+    std::uint64_t quotient = muldiv(numVal, kTenTO17, denVal);
+    int offset = numOffset - denOffset - 17;
+
+    // An integral (XRP) numerator is not scaled down to 16 digits, so the
+    // quotient can land in [2^63, 2^64). The STAmount constructor reads
+    // that as a negative IOU mantissa, and the +5 can wrap. Drop a digit
+    // first; the result is canonicalized to 16 digits anyway.
+    if (quotient > static_cast<std::uint64_t>(std::numeric_limits<std::int64_t>::max()) - 5 &&
+        isFeatureEnabled(featureMPTokensV2, /*resultIfNoRules*/ true))
+    {
+        quotient /= 10;
+        ++offset;
+    }
+
+    return STAmount(asset, quotient + 5, offset, num.negative() != den.negative());
 }
 
 STAmount
@@ -1470,28 +1487,28 @@ roundNumberResult(
     // and for materializing the final integral amount.
     NumberRoundModeGuard const finalRound(roundMode(resultNegative, roundUp));
     auto result = STAmount{asset, number};
+    // An integral result can't underflow: when roundUp is set, roundMode()
+    // above selects Upward, and materializing a Number into an integral
+    // STAmount honors that mode (Number::operator rep()), so any positive
+    // value rounds up to at least 1.
     [[maybe_unused]] bool const nonzeroPositiveRoundUp =
         roundUp && !resultNegative && number != beast::kZero;
     ALWAYS(
-        !nonzeroPositiveRoundUp || result != beast::kZero,
-        "xrpl::roundNumberResult : positive rounded-up MPT result is representable");
+        !nonzeroPositiveRoundUp || !asset.integral() || result != beast::kZero,
+        "xrpl::roundNumberResult : positive rounded-up integral result is representable");
 
     if (roundUp && !resultNegative && !result)
     {
-        // Intended to preserve existing mulRound/divRound behavior for a
-        // positive result too small to represent in the target asset.
-        //
-        // Unreachable in practice: when roundUp is set, roundMode() above
-        // selects Upward, and materializing a Number into an STAmount honors
-        // that mode (Number::operator rep()), so any positive value rounds up
-        // to at least the smallest representable unit. Hence, a positive result
-        // is never !result here; the only zero case is a zero operand, which
-        // the mulRound/divRound callers handle before reaching this function.
-        // LCOV_EXCL_START
+        // Preserve existing mulRound/divRound behavior for a positive result
+        // too small to represent in the target asset. An IOU result with an
+        // MPT operand (e.g. 1 MPT / 1e95) below the smallest IOU is flushed to
+        // zero by IOUAmount normalization regardless of the rounding mode, so
+        // snap it up to the smallest positive IOU. The only zero case for an
+        // integral result is a zero operand, which the mulRound/divRound
+        // callers handle before reaching this function.
         if (asset.integral())
-            return STAmount{asset, 1};
+            return STAmount{asset, 1};  // LCOV_EXCL_LINE
         return STAmount{asset, STAmount::kMinValue, STAmount::kMinOffset, false};
-        // LCOV_EXCL_STOP
     }
 
     return result;
@@ -1540,11 +1557,19 @@ mulRoundImpl(STAmount const& v1, STAmount const& v2, Asset const& asset, bool ro
 
     bool const resultNegative = v1.negative() != v2.negative();
 
-    if (asset.holds<MPTIssue>() && isFeatureEnabled(featureMPTokensV2, false))
+    // The legacy path below assumes 16-digit mantissas. An MPT mantissa is the
+    // raw 63-bit balance, so any MPT operand (not just an MPT result) can
+    // overflow it: a large MPT amount times an IOU-shaped rate into an XRP or
+    // IOU result is the offer-crossing remainder and partial-fill case. Use
+    // Number arithmetic under MPTokensV2 whenever an MPT is involved.
+    //
+    // Outside a transaction (no current rules, e.g. pathfinding) default to
+    // the Number path: an MPT operand can only reach here through MPT
+    // offers or AMMs, which require MPTokensV2, so this keeps RPC quotes on
+    // the same arithmetic as the transaction they describe.
+    if (isFeatureEnabled(featureMPTokensV2, /*resultIfNoRules*/ true) &&
+        (asset.holds<MPTIssue>() || v1.holds<MPTIssue>() || v2.holds<MPTIssue>()))
     {
-        // MPT DEX can combine 63-bit MPT amounts with IOU-shaped transfer
-        // rates. Use Number arithmetic under MPTokensV2 so the rounded
-        // operation is not limited by the legacy uint64_t scaled mantissa.
         Number result;
         {
             NumberRoundModeGuard const operationRound(roundMode(resultNegative, roundUp));
@@ -1642,9 +1667,12 @@ divRoundImpl(STAmount const& num, STAmount const& den, Asset const& asset, bool
 
     bool const resultNegative = (num.negative() != den.negative());
 
+    // See mulRoundImpl: any MPT operand, not just an MPT result, and the
+    // Number path when there are no current rules.
     // fixCleanup3_5_0: the legacy path below overflows on large MPT amounts.
-    if (asset.holds<MPTIssue>() &&
-        (isFeatureEnabled(featureMPTokensV2, true) || isFeatureEnabled(fixCleanup3_5_0, true)))
+    auto const enabled = isFeatureEnabled(featureMPTokensV2, /*resultIfNoRules*/ true) ||
+        isFeatureEnabled(fixCleanup3_5_0, /*resultIfNoRules*/ true);
+    if ((asset.holds<MPTIssue>() || num.holds<MPTIssue>() || den.holds<MPTIssue>()) && enabled)
     {
         // Match the multiply path above: Number performs the rounded
         // operation, then STAmount materializes the final MPT amount using the
@@ -1735,6 +1763,24 @@ divRoundStrict(STAmount const& num, STAmount const& den, Asset const& asset, boo
     return divRoundImpl<NumberRoundModeGuard>(num, den, asset, roundUp);
 }
 
+STAmount
+mulRatio(STAmount const& amt, std::uint32_t num, std::uint32_t den, Number::RoundingMode rounding)
+{
+    XRPL_ASSERT(
+        rounding == Number::RoundingMode::Upward || rounding == Number::RoundingMode::Downward,
+        "xrpl::mulRatio(STAmount) : rounding is Upward or Downward");
+    bool const roundUp = rounding == Number::RoundingMode::Upward;
+    return amt.asset().visit(
+        [&](Issue const& issue) -> STAmount {
+            if (amt.native())
+                return mulRatio(amt.xrp(), num, den, roundUp);
+            return {mulRatio(amt.iou(), num, den, roundUp), issue};
+        },
+        [&](MPTIssue const& issue) -> STAmount {
+            return {mulRatio(amt.mpt(), num, den, roundUp), issue};
+        });
+}
+
 [[nodiscard]] bool
 STAmount::isZeroAtScale(int scale) const
 {

src/libxrpl/protocol/STPathSet.cpp

@@ -1,11 +1,10 @@
 #include <xrpl/protocol/STPathSet.h>
 
 #include <xrpl/basics/CountedObject.h>
-#include <xrpl/basics/Log.h>
 #include <xrpl/basics/UnorderedContainers.h>
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/basics/contract.h>
-#include <xrpl/beast/hash/uhash.h>
+#include <xrpl/basics/safe_cast.h>
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/json/json_value.h>
 #include <xrpl/protocol/AccountID.h>
@@ -17,7 +16,9 @@
 #include <xrpl/protocol/jss.h>
 
 #include <algorithm>
-#include <cstddef>
+#include <concepts>
+#include <cstdint>
+#include <format>
 #include <memory>
 #include <stdexcept>
 #include <utility>
@@ -25,41 +26,6 @@
 
 namespace xrpl {
 
-std::size_t
-STPathElement::getHash(STPathElement const& element)
-{
-    std::size_t hashAccount = 2654435761;
-    std::size_t hashCurrency = 2654435761;
-    std::size_t hashIssuer = 2654435761;
-
-    // NIKB NOTE: This doesn't have to be a secure hash as speed is more
-    //            important. We don't even really need to fully hash the whole
-    //            base_uint here, as a few bytes would do for our use.
-    //
-    // The note above is only true because the result of this function reaches
-    // nothing but STPathElement::operator==, where it is a fast-reject
-    // prefilter ahead of the field comparisons that decide the answer.  Do not
-    // use it to key a container.
-
-    for (auto const x : element.getAccountID())
-        hashAccount += (hashAccount * 257) ^ x;
-
-    // Check pathAsset type instead of element's type_
-    // In some cases type_ might be account but the asset
-    // is still set to either MPT or currency (see Pathfinder::addLink())
-    element.getPathAsset().visit(
-        [&](MPTID const& mpt) { hashCurrency += beast::Uhash<>{}(mpt); },
-        [&](Currency const& currency) {
-            for (auto const x : currency)
-                hashCurrency += (hashCurrency * 509) ^ x;
-        });
-
-    for (auto const x : element.getIssuerID())
-        hashIssuer += (hashIssuer * 911) ^ x;
-
-    return (hashAccount ^ hashCurrency ^ hashIssuer);
-}
-
 // For guidance on deciding which option to pursue:
 // 1. Try to decrease the size of the STPathSet first.  For instance, if a std::optional was
 //    injected into the type, could you get the same functionality using a std::unique_ptr instead?
@@ -108,62 +74,57 @@ STPathSet::operator=(STPathSet const& other)
 STPathSet::STPathSet(SerialIter& sit, SField const& name) : STBase(name)
 {
     std::vector<STPathElement> path;
-    for (;;)
-    {
-        int const iType = sit.get8();
 
-        if (iType == STPathElement::TypeNone || iType == STPathElement::TypeBoundary)
+    STPathElementType type = STPathElementType::None;
+
+    do
+    {
+        type = safeCast<STPathElementType>(sit.get8());
+
+        if (type == STPathElementType::None || type == STPathElementType::Boundary)
         {
             if (path.empty())
-            {
-                JLOG(debugLog().error()) << "Empty path in pathset";
-                Throw<std::runtime_error>("empty path");
-            }
+                Throw<std::runtime_error>("bad path element: empty path");
 
             // Move rather than converting the vector to an STPath by copy.
             value_.emplace_back(std::move(path));
             path.clear();
 
-            if (iType == STPathElement::TypeNone)
-                return;
+            continue;
         }
-        else if ((iType & ~STPathElement::TypeAll) != 0)
-        {
-            JLOG(debugLog().error()) << "Bad path element " << iType << " in pathset";
-            Throw<std::runtime_error>("bad path element");
-        }
-        else
-        {
-            auto const hasAccount = (iType & STPathElement::TypeAccount) != 0u;
-            auto const hasCurrency = (iType & STPathElement::TypeCurrency) != 0u;
-            auto const hasIssuer = (iType & STPathElement::TypeIssuer) != 0u;
-            auto const hasMPT = (iType & STPathElement::TypeMpt) != 0u;
 
-            AccountID account;
-            PathAsset asset;
-            AccountID issuer;
+        if ((type & ~STPathElementType::All) != STPathElementType::None)
+            Throw<std::runtime_error>(
+                std::format("bad path element: <{:#04x}>", std::to_underlying(type)));
 
-            if (hasAccount)
-                account = sit.get160();
+        bool const hasAccount = (type & STPathElementType::Account) == STPathElementType::Account;
+        bool const hasCurrency =
+            (type & STPathElementType::Currency) == STPathElementType::Currency;
+        bool const hasMPT = (type & STPathElementType::Mpt) == STPathElementType::Mpt;
+        bool const hasIssuer = (type & STPathElementType::Issuer) == STPathElementType::Issuer;
 
-            if (hasCurrency && hasMPT)
-            {
-                JLOG(debugLog().error()) << "Bad path element MPT and Currency in pathset";
-                Throw<std::runtime_error>("bad path element: MPT and Currency");
-            }
+        if (hasCurrency && hasMPT)
+            Throw<std::runtime_error>("bad path element: MPT and Currency");
 
-            if (hasCurrency)
-                asset = Currency::fromRaw(sit.get160());
+        AccountID account;
+        PathAsset asset;
+        AccountID issuer;
 
-            if (hasMPT)
-                asset = sit.get192();
+        if (hasAccount)
+            account = sit.get160();
 
-            if (hasIssuer)
-                issuer = sit.get160();
+        if (hasCurrency)
+            asset = Currency::fromRaw(sit.get160());
 
-            path.emplace_back(account, asset, issuer, hasCurrency || hasMPT);
-        }
-    }
+        if (hasMPT)
+            asset = sit.get192();
+
+        if (hasIssuer)
+            issuer = sit.get160();
+
+        path.emplace_back(account, asset, issuer, hasCurrency || hasMPT);
+
+    } while (type != STPathElementType::None);
 }
 
 STBase*
@@ -217,24 +178,22 @@ STPath::getJson(JsonOptions) const
     for (auto const& it : path_)
     {
         json::Value elem(json::ValueType::Object);
-        auto const iType = it.getNodeType();
 
-        elem[jss::type] = iType;
+        elem[jss::type] = safeCast<std::uint32_t>(it.getNodeType());
 
-        if ((iType & STPathElement::TypeAccount) != 0u)
+        if (it.isType(STPathElementType::Account))
             elem[jss::account] = to_string(it.getAccountID());
 
         XRPL_ASSERT(
-            ((iType & STPathElement::TypeCurrency) == 0u) ||
-                ((iType & STPathElement::TypeMpt) == 0u),
+            !(it.hasCurrency() && it.hasMPT()),
             "xrpl::STPath::getJson : not type Currency and MPT");
-        if ((iType & STPathElement::TypeCurrency) != 0u)
+        if (it.hasCurrency())
             elem[jss::currency] = to_string(it.getCurrency());
 
-        if ((iType & STPathElement::TypeMpt) != 0u)
+        if (it.hasMPT())
             elem[jss::mpt_issuance_id] = to_string(it.getMPTID());
 
-        if ((iType & STPathElement::TypeIssuer) != 0u)
+        if (it.hasIssuer())
             elem[jss::issuer] = to_string(it.getIssuerID());
 
         ret.append(elem);
@@ -266,34 +225,42 @@ STPathSet::add(Serializer& s) const
     XRPL_ASSERT(getFName().fieldType == STI_PATHSET, "xrpl::STPathSet::add : valid field type");
     bool first = true;
 
+    // Workaround, since `Serializer` does not accept strongly-typed enums
+    // yet. When support is added, the static_assert will trigger, and the
+    // lambda can be removed entirely.
+    auto const toByte = [](std::same_as<STPathElementType> auto t) noexcept {
+        static_assert(
+            !requires(Serializer& ser) { ser.add8(t); },
+            "Serializer::add8 now accepts STPathElementType directly; remove toByte.");
+        return std::to_underlying(t);
+    };
+
     for (auto const& spPath : value_)
     {
         if (!first)
-            s.add8(STPathElement::TypeBoundary);
+            s.add8(toByte(STPathElementType::Boundary));
 
         for (auto const& speElement : spPath)
         {
-            int const iType = speElement.getNodeType();
+            s.add8(toByte(speElement.getNodeType()));
 
-            s.add8(iType);
-
-            if ((iType & STPathElement::TypeAccount) != 0u)
+            if (speElement.isType(STPathElementType::Account))
                 s.addBitString(speElement.getAccountID());
 
-            if ((iType & STPathElement::TypeMpt) != 0u)
+            if (speElement.hasMPT())
                 s.addBitString(speElement.getMPTID());
 
-            if ((iType & STPathElement::TypeCurrency) != 0u)
+            if (speElement.hasCurrency())
                 s.addBitString(speElement.getCurrency());
 
-            if ((iType & STPathElement::TypeIssuer) != 0u)
+            if (speElement.hasIssuer())
                 s.addBitString(speElement.getIssuerID());
         }
 
         first = false;
     }
 
-    s.add8(STPathElement::TypeNone);
+    s.add8(toByte(STPathElementType::None));
 }
 
 }  // namespace xrpl

src/libxrpl/protocol/TER.cpp

@@ -137,6 +137,8 @@ transResults()
         MAKE_ERROR(tefBAD_PATH_COUNT,              "Malformed: Too many paths."),
         MAKE_ERROR(tefNO_BYTECODE,                 "There is no WASM code to run, but a WASM-specific field was included."),
         MAKE_ERROR(tefBYTECODE_NOT_INCLUDED,       "WASM code requires a field that was not included."),
+        MAKE_ERROR(tefTEMP_DISABLED,               "The transaction requires logic that is currently temporarily disabled."),
+        MAKE_ERROR(tefEXCEEDS_LIMIT,               "The transaction exceeds a limit set by fee voting."),
 
         MAKE_ERROR(telLOCAL_ERROR,            "Local failure."),
         MAKE_ERROR(telBAD_DOMAIN,             "Domain too long."),
@@ -209,7 +211,6 @@ transResults()
         MAKE_ERROR(temINVALID_INNER_BATCH,       "Malformed: Invalid inner batch transaction."),
         MAKE_ERROR(temBAD_CIPHERTEXT,            "Malformed: Invalid ciphertext."),
         MAKE_ERROR(temINVALID_BYTECODE,          "Malformed: Provided byte code is invalid."),
-        MAKE_ERROR(temTEMP_DISABLED,             "The transaction requires logic that is currently temporarily disabled."),
 
         MAKE_ERROR(terRETRY,                  "Retry transaction."),
         MAKE_ERROR(terFUNDS_SPENT,            "DEPRECATED."),
@@ -228,6 +229,7 @@ transResults()
         MAKE_ERROR(terNO_DELEGATE_PERMISSION, "Delegated account lacks permission to perform this transaction."),
         MAKE_ERROR(terLOCKED,                 "Fund is locked."),
         MAKE_ERROR(terNO_PERMISSION,          "No permission to perform requested operation."),
+        MAKE_ERROR(terTICKET_RESERVED,        "Ticket is reserved."),
 
         MAKE_ERROR(tesSUCCESS,                "The transaction was applied. Only final in a validated ledger."),
     };

src/libxrpl/protocol/XRPAmount.cpp

@@ -0,0 +1,54 @@
+#include <xrpl/protocol/XRPAmount.h>
+
+#include <xrpl/basics/MathUtilities.h>
+#include <xrpl/basics/contract.h>
+#include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/Rules.h>
+
+#include <stdexcept>
+
+namespace xrpl {
+
+XRPAmount&
+XRPAmount::operator+=(value_type const& rhs)
+{
+    if (auto const result = checkedAdd(drops_, rhs))
+    {
+        drops_ = *result;
+        return *this;
+    }
+    if (isFeatureEnabled(fixCleanup3_5_0, /*resultIfNoRules*/ true))
+        Throw<std::overflow_error>("XRPAmount::operator+= overflow");
+    drops_ += rhs;
+    return *this;
+}
+
+XRPAmount&
+XRPAmount::operator-=(value_type const& rhs)
+{
+    if (auto const result = checkedSub(drops_, rhs))
+    {
+        drops_ = *result;
+        return *this;
+    }
+    if (isFeatureEnabled(fixCleanup3_5_0, /*resultIfNoRules*/ true))
+        Throw<std::overflow_error>("XRPAmount::operator-= overflow");
+    drops_ -= rhs;
+    return *this;
+}
+
+XRPAmount&
+XRPAmount::operator*=(value_type const& rhs)
+{
+    if (auto const result = checkedMul(drops_, rhs))
+    {
+        drops_ = *result;
+        return *this;
+    }
+    if (isFeatureEnabled(fixCleanup3_5_0, /*resultIfNoRules*/ true))
+        Throw<std::overflow_error>("XRPAmount::operator*= overflow");
+    drops_ *= rhs;
+    return *this;
+}
+
+}  // namespace xrpl

src/libxrpl/server/JSONRPCUtil.cpp

@@ -33,10 +33,7 @@ getHTTPHeaderTimestamp()
 void
 httpReply(int nStatus, std::string const& content, json::Output const& output, beast::Journal j)
 {
-    // The status only. The body is a reply, which carries a credential when the
-    // command is a keygen, and this library cannot mask one: the caller logs the
-    // masked body at debug.
-    JLOG(j.trace()) << "HTTP Reply " << nStatus;
+    JLOG(j.trace()) << "HTTP Reply " << nStatus << " " << content;
 
     if (content.empty() && nStatus == 401)
     {

src/libxrpl/shamap/SHAMap.cpp

@@ -26,6 +26,7 @@
 
 #include <boost/smart_ptr/intrusive_ptr.hpp>
 
+#include <atomic>
 #include <cstdint>
 #include <exception>
 #include <functional>
@@ -77,14 +78,23 @@ SHAMap::SHAMap(SHAMap const& other, bool isMutable)
     : f_(other.f_)
     , journal_(other.f_.journal())
     , cowid_(other.cowid_ + 1)
-    , ledgerSeq_(other.ledgerSeq_)
+    , ledgerSeq_(other.ledgerSeq())
     , root_(other.root_)
-    , state_(isMutable ? SHAMapState::Modifying : SHAMapState::Immutable)
     , type_(other.type_)
     , backed_(other.backed_)
 {
+    // A snapshot shares the source's root, so Invalid carries over. Read once into a local, since
+    // the source's state can change while this runs.
+    auto const otherState = other.state();
+    auto const ownState = [&] {
+        if (otherState == SHAMapState::Invalid)
+            return SHAMapState::Invalid;
+        return isMutable ? SHAMapState::Modifying : SHAMapState::Immutable;
+    }();
+    state_.store(ownState, std::memory_order_release);
+
     // If either map may change, they cannot share nodes
-    if ((state_ != SHAMapState::Immutable) || (other.state_ != SHAMapState::Immutable))
+    if ((ownState != SHAMapState::Immutable) || (otherState != SHAMapState::Immutable))
     {
         unshare();
     }
@@ -105,7 +115,7 @@ SHAMap::dirtyUp(NodePathStack& stack, UInt256 const& target, SHAMapTreeNodePtr c
     // child can be an inner node or a leaf
 
     XRPL_ASSERT(
-        (state_ != SHAMapState::Synching) && (state_ != SHAMapState::Immutable),
+        (state() != SHAMapState::Synching) && (state() != SHAMapState::Immutable),
         "xrpl::SHAMap::dirtyUp : valid state");
     XRPL_ASSERT(child && (child->cowid() == cowid_), "xrpl::SHAMap::dirtyUp : valid child input");
 
@@ -170,7 +180,7 @@ SHAMapTreeNodePtr
 SHAMap::fetchNodeFromDB(SHAMapHash const& hash) const
 {
     XRPL_ASSERT(backed_, "xrpl::SHAMap::fetchNodeFromDB : is backed");
-    auto const obj = f_.db().fetchNodeObject(hash.asUInt256(), ledgerSeq_);
+    auto const obj = f_.db().fetchNodeObject(hash.asUInt256(), ledgerSeq());
     return finishFetch(hash, obj);
 }
 
@@ -183,10 +193,17 @@ SHAMap::finishFetch(SHAMapHash const& hash, std::shared_ptr<NodeObject> const& o
     {
         if (!object)
         {
-            if (full_)
+            // A missing node disproves full_, so withdraw it and report the gap. The exchange
+            // makes exactly one reader report it, and its acquire pairs with the release store in
+            // setFull(). It needs no release: the only other reader of full_ is this same path,
+            // and a reader that loses the exchange does nothing with what the winner did. The load
+            // ahead of it is relaxed, since all it decides is whether to try the exchange: a stale
+            // true costs one exchange that loses, and a stale false means another reader won, or
+            // setFull() is not visible yet and the gap goes unreported.
+            if (full_.load(std::memory_order_relaxed) &&
+                full_.exchange(false, std::memory_order_acquire))
             {
-                full_ = false;
-                f_.missingNodeAcquireBySeq(ledgerSeq_, hash.asUInt256());
+                f_.missingNodeAcquireBySeq(ledgerSeq(), hash.asUInt256());
             }
             return {};
         }
@@ -219,7 +236,7 @@ SHAMap::checkFilter(SHAMapHash const& hash, SHAMapSyncFilter const* filter) cons
             auto node = SHAMapTreeNode::makeFromPrefix(makeSlice(*nodeData), hash);
             if (node)
             {
-                filter->gotNode(true, hash, ledgerSeq_, std::move(*nodeData), node->getType());
+                filter->gotNode(true, hash, ledgerSeq(), std::move(*nodeData), node->getType());
                 if (backed_)
                     canonicalize(hash, node);
             }
@@ -399,7 +416,7 @@ SHAMap::descendAsync(
         {
             f_.db().asyncFetch(
                 hash.asUInt256(),
-                ledgerSeq_,
+                ledgerSeq(),
                 [this, hash, cb{std::move(callback)}](std::shared_ptr<NodeObject> const& object) {
                     auto const node = finishFetch(hash, object);
                     cb(node, hash);
@@ -424,7 +441,7 @@ SHAMap::unshareNode(intr_ptr::SharedPtr<Node> node, SHAMapNodeID const& nodeID)
     if (node->cowid() != cowid_)
     {
         // have a CoW
-        XRPL_ASSERT(state_ != SHAMapState::Immutable, "xrpl::SHAMap::unshareNode : not immutable");
+        XRPL_ASSERT(state() != SHAMapState::Immutable, "xrpl::SHAMap::unshareNode : not immutable");
         node = intr_ptr::staticPointerCast<Node>(node->clone(cowid_));
         if (nodeID.isRoot())
             root_ = node;
@@ -637,7 +654,7 @@ bool
 SHAMap::delItem(UInt256 const& id)
 {
     // delete the item with this ID
-    XRPL_ASSERT(state_ != SHAMapState::Immutable, "xrpl::SHAMap::delItem : not immutable");
+    XRPL_ASSERT(state() != SHAMapState::Immutable, "xrpl::SHAMap::delItem : not immutable");
 
     NodePathStack stack;
     walkTowardsKey(id, &stack);
@@ -719,7 +736,7 @@ SHAMap::delItem(UInt256 const& id)
 bool
 SHAMap::addGiveItem(SHAMapNodeType type, boost::intrusive_ptr<SHAMapItem const> item)
 {
-    XRPL_ASSERT(state_ != SHAMapState::Immutable, "xrpl::SHAMap::addGiveItem : not immutable");
+    XRPL_ASSERT(state() != SHAMapState::Immutable, "xrpl::SHAMap::addGiveItem : not immutable");
     XRPL_ASSERT(type != SHAMapNodeType::TnInner, "xrpl::SHAMap::addGiveItem : valid type input");
 
     // add the specified item, does not update
@@ -810,7 +827,7 @@ SHAMap::updateGiveItem(SHAMapNodeType type, boost::intrusive_ptr<SHAMapItem cons
     // can't change the tag but can change the hash
     UInt256 const tag = item->key();
 
-    XRPL_ASSERT(state_ != SHAMapState::Immutable, "xrpl::SHAMap::updateGiveItem : not immutable");
+    XRPL_ASSERT(state() != SHAMapState::Immutable, "xrpl::SHAMap::updateGiveItem : not immutable");
 
     NodePathStack stack;
     walkTowardsKey(tag, &stack);
@@ -901,7 +918,7 @@ SHAMap::writeNode(NodeObjectType t, SHAMapTreeNodePtr node) const
 
     Serializer s;
     node->serializeWithPrefix(s);
-    f_.db().store(t, std::move(s.modData()), node->getHash().asUInt256(), ledgerSeq_);
+    f_.db().store(t, std::move(s.modData()), node->getHash().asUInt256(), ledgerSeq());
     return node;
 }
 

src/libxrpl/shamap/SHAMapInnerNode.cpp

@@ -16,6 +16,7 @@
 #include <xrpl/shamap/detail/TaggedPointer.h>
 #include <xrpl/shamap/detail/TaggedPointer.ipp>
 
+#include <atomic>
 #include <cstddef>
 #include <cstdint>
 #include <mutex>
@@ -77,7 +78,9 @@ SHAMapInnerNode::clone(std::uint32_t cowid) const
     auto p = intr_ptr::makeShared<SHAMapInnerNode>(cowid, branchCount);
     p->hash_ = hash_;
     p->isBranch_ = isBranch_;
-    p->fullBelowGen_ = fullBelowGen_;
+    // Relaxed, as everywhere. p is not reachable by another thread until this returns.
+    p->fullBelowGen_.store(
+        fullBelowGen_.load(std::memory_order_relaxed), std::memory_order_relaxed);
     SHAMapHash* cloneHashes = nullptr;
     SHAMapHash* thisHashes = nullptr;
     SHAMapTreeNodePtr* cloneChildren = nullptr;

src/libxrpl/shamap/SHAMapSync.cpp

@@ -31,6 +31,25 @@
 
 namespace xrpl {
 
+namespace {
+
+/**
+ * Whether a depth is at or past the deepest an inner node may occupy.
+ *
+ * Nibbles run out at SHAMap::kLeafDepth, so only a leaf may sit there. True for
+ * every deeper position too, which lies past the end of a key.
+ *
+ * @param depth The depth to judge.
+ * @return Whether an inner node at that depth makes the map impossible.
+ */
+[[nodiscard]] bool
+isLeafDepth(unsigned int depth)
+{
+    return depth >= SHAMap::kLeafDepth;
+}
+
+}  // namespace
+
 void
 SHAMap::visitLeaves(
     std::function<void(boost::intrusive_ptr<SHAMapItem const> const& item)> const& leafFunction)
@@ -143,13 +162,10 @@ SHAMap::visitDifferences(
         if (!function(*node))
             return;
 
-        // Nibbles run out at kLeafDepth, so only a leaf belongs there. A well-formed map never
-        // holds an inner node at that depth: addKnownNode marks the map invalid rather than hooking
-        // one in, and fetch-pack data is hash-verified against a validated root, so reaching this
-        // means a defect or a corrupt store, not something a peer can provoke. Report the node
-        // anyway - the wire form carries no depth, and the recipient hooks blobs in by hash - but
-        // skip the children rather than letting getChildNodeID throw on them.
-        if (nodeID.getDepth() >= kLeafDepth)
+        // Only a leaf belongs at kLeafDepth. The node is still reported, since the wire form
+        // carries no depth and the recipient hooks blobs by hash. Its children are skipped, since
+        // getChildNodeID has no answer past kLeafDepth.
+        if (isLeafDepth(nodeID.getDepth()))
         {
             // LCOV_EXCL_START
             UNREACHABLE("xrpl::SHAMap::visitDifferences : inner node at leaf depth");
@@ -207,7 +223,12 @@ SHAMap::gmnProcessNodes(MissingNodes& mn, MissingNodes::StackEntry& se)
             // we already know this child node is missing
             fullBelow = false;
         }
-        else if (!backed_ || !f_.getFullBelowCache()->touchIfExists(childHash.asUInt256()))
+        // The depth test precedes the cache lookup for the same reason it does in addKnownNode():
+        // the cache is keyed by node hash and shared across maps, and a hash covers a node's
+        // children but not its depth. Skipping the shortcut forgoes an optimization only.
+        else if (
+            !backed_ || isLeafDepth(nodeID.getDepth() + 1) ||
+            !f_.getFullBelowCache()->touchIfExists(childHash.asUInt256()))
         {
             bool pending = false;
             auto d = descendAsync(
@@ -238,6 +259,17 @@ SHAMap::gmnProcessNodes(MissingNodes& mn, MissingNodes::StackEntry& se)
                 if (--mn.max <= 0)
                     return;
             }
+            else if (d->isInner() && isLeafDepth(nodeID.getDepth() + 1))
+            {
+                // Only a leaf belongs that deep (see isLeafDepth and SHAMap::addKnownNode). A node
+                // resolved locally reaches the walk without passing through addKnownNode(), so the
+                // walk reaches this verdict itself. Ordered ahead of the full-below test below,
+                // which canonicalization shares across maps.
+                JLOG(journal_.warn()) << "Inner node at branch " << branch << " below " << nodeID
+                                      << " makes the map invalid";
+                setInvalid();
+                return;
+            }
             else if (d->isInner() && !safeDowncast<SHAMapInnerNode*>(d)->isFullBelow(mn.generation))
             {
                 mn.stack.push(se);
@@ -301,6 +333,8 @@ SHAMap::gmnProcessDeferredReads(MissingNodes& mn)
         }
         else if ((mn.max > 0) && mn.missingHashes.insert(nodeHash).second)
         {
+            // getChildNodeID() is safe here: gmnProcessNodes refuses to descend into an inner node
+            // at kLeafDepth, so a deferred parent sits at most one level above it.
             mn.missingNodes.emplace_back(parentID.getChildNodeID(branch), nodeHash.asUInt256());
             --mn.max;
         }
@@ -311,17 +345,20 @@ SHAMap::gmnProcessDeferredReads(MissingNodes& mn)
     mn.deferred = 0;
 }
 
-/**
- * Get a list of node IDs and hashes for nodes that are part of this SHAMap
- * but not available locally.  The filter can hold alternate sources of
- * nodes that are not permanently stored locally
- */
 std::vector<std::pair<SHAMapNodeID, UInt256>>
 SHAMap::getMissingNodes(int max, SHAMapSyncFilter const* filter)
 {
     XRPL_ASSERT(root_->getHash().isNonZero(), "xrpl::SHAMap::getMissingNodes : nonzero root hash");
     XRPL_ASSERT(max > 0, "xrpl::SHAMap::getMissingNodes : valid max input");
 
+    if (!isValid())
+    {
+        // The root node's own hash, since getHash() unshares the tree on a zero hash.
+        JLOG(journal_.warn()) << "getMissingNodes called on an invalid map, root hash "
+                              << root_->getHash() << " seq " << ledgerSeq();
+        return {};
+    }
+
     MissingNodes mn(
         max,
         filter,
@@ -354,6 +391,11 @@ SHAMap::getMissingNodes(int max, SHAMapSyncFilter const* filter)
         {
             gmnProcessNodes(mn, pos);
 
+            // The walk just invalidated the map. The loop stops descending here but falls through
+            // to the drain below, since every posted read must be drained while `mn` is alive.
+            if (!isValid())
+                break;
+
             if (mn.max <= 0)
                 break;
 
@@ -383,6 +425,11 @@ SHAMap::getMissingNodes(int max, SHAMapSyncFilter const* filter)
         if (mn.deferred != 0)
             gmnProcessDeferredReads(mn);
 
+        // Reads are drained, so the map can be abandoned. What was collected belongs to a tree
+        // that cannot exist.
+        if (!isValid())
+            return {};
+
         if (mn.max <= 0)
             return std::move(mn.missingNodes);
 
@@ -416,6 +463,11 @@ SHAMap::getMissingNodes(int max, SHAMapSyncFilter const* filter)
 
     } while (node != nullptr);
 
+    // addKnownNode() on another thread can write the verdict after the loop's own test, so the map
+    // is judged once more before the result is returned.
+    if (!isValid())
+        return {};  // LCOV_EXCL_LINE: only that other thread reaches this, so no test does
+
     if (mn.missingNodes.empty())
         clearSynching();
 
@@ -527,11 +579,19 @@ SHAMap::addRootNode(
     XRPL_ASSERT(cowid_ >= 1, "xrpl::SHAMap::addRootNode : valid cowid");
     XRPL_ASSERT(rootNode, "xrpl::SHAMap::addRootNode : non-null root node");
 
-    // we already have a root_ node
+    // A map syncs against one hash and installs a root once, so a root already held is a duplicate
+    // only once it hashes to the hash asked for.
     if (root_->getHash().isNonZero())
     {
         JLOG(journal_.trace()) << "Got root node, already have one";
-        XRPL_ASSERT(root_->getHash() == hash, "xrpl::SHAMap::addRootNode : valid hash");
+
+        if (root_->getHash() != hash)
+        {
+            JLOG(journal_.warn()) << "Root node offered under hash " << hash
+                                  << ", but the map holds " << root_->getHash();
+            return SHAMapAddNode::invalid();
+        }
+
         return SHAMapAddNode::duplicate();
     }
 
@@ -555,7 +615,7 @@ SHAMap::addRootNode(
         Serializer s;
         root_->serializeWithPrefix(s);
         filter->gotNode(
-            false, root_->getHash(), ledgerSeq_, std::move(s.modData()), root_->getType());
+            false, root_->getHash(), ledgerSeq(), std::move(s.modData()), root_->getType());
     }
 
     return SHAMapAddNode::useful();
@@ -598,7 +658,13 @@ SHAMap::addKnownNode(
         }
 
         auto childHash = inner->getChildHash(branch);
-        if (f_.getFullBelowCache()->touchIfExists(childHash.asUInt256()))
+
+        // Depth before the cache: the cache is keyed by node hash and shared across the family, and
+        // a hash covers a node's children but not its depth, so the same subtree can be cached as
+        // complete at one depth and reached at another. Skipping the shortcut only forgoes an
+        // optimization.
+        if (!isLeafDepth(currNodeID.getDepth() + 1) &&
+            f_.getFullBelowCache()->touchIfExists(childHash.asUInt256()))
         {
             return SHAMapAddNode::duplicate();
         }
@@ -616,25 +682,32 @@ SHAMap::addKnownNode(
             return SHAMapAddNode::invalid();
         }
 
-        // Inner nodes must be at a level strictly less than 64
-        // but leaf nodes (while notionally at level 64) can be
-        // at any depth up to and including 64:
-        if ((currNodeID.getDepth() > kLeafDepth) ||
-            (treeNode->isInner() && currNodeID.getDepth() == kLeafDepth))
+        // Only leaves may sit at kLeafDepth (see isLeafDepth), so an inner node there makes the map
+        // impossible. The node is reported as bad data.
+        //
+        // Every node from the root down hash-verified to get here, so it is the requested root hash
+        // itself that commits to a shape no valid tree can have. The verdict belongs to that hash
+        // rather than to our copy of the tree.
+        bool const badDepth = treeNode->isInner() && isLeafDepth(currNodeID.getDepth());
+        SOMETIMES(badDepth, "xrpl::SHAMap::addKnownNode : map is invalid");
+        if (badDepth)
         {
-            // Map is provably invalid
-            state_ = SHAMapState::Invalid;
-            return SHAMapAddNode::useful();
+            JLOG(journal_.warn()) << "Node " << nodeID << " makes the map invalid at "
+                                  << currNodeID;
+            setInvalid();
+            return SHAMapAddNode::invalid();
         }
 
-        if (currNodeID != nodeID)
+        // The data hashes to the child at currNodeID but claims to belong at nodeID, so it is not
+        // the node that was asked for. Only the label is wrong, so the map stays sound and the node
+        // is still obtainable from another sender.
+        bool const badPosition = (currNodeID != nodeID);
+        SOMETIMES(badPosition, "xrpl::SHAMap::addKnownNode : node ID does not match its position");
+        if (badPosition)
         {
-            // Either this node is broken or we didn't request it (yet)
-            JLOG(journal_.warn()) << "unable to hook node " << nodeID;
-            JLOG(journal_.info()) << " stuck at " << currNodeID;
-            JLOG(journal_.info()) << "got depth=" << nodeID.getDepth()
-                                  << ", walked to= " << currNodeID.getDepth();
-            return SHAMapAddNode::useful();
+            JLOG(journal_.warn()) << "Unable to hook node " << nodeID << ", stuck at "
+                                  << currNodeID;
+            return SHAMapAddNode::invalid();
         }
 
         if (backed_)
@@ -647,7 +720,7 @@ SHAMap::addKnownNode(
             Serializer s;
             treeNode->serializeWithPrefix(s);
             filter->gotNode(
-                false, childHash, ledgerSeq_, std::move(s.modData()), treeNode->getType());
+                false, childHash, ledgerSeq(), std::move(s.modData()), treeNode->getType());
         }
 
         return SHAMapAddNode::useful();
@@ -766,7 +839,7 @@ SHAMap::hasLeafNode(UInt256 const& tag, SHAMapHash const& targetNodeHash) const
         // Same kLeafDepth hazard as in visitDifferences above. That guard bounds the caller's own
         // traversal, not the map queried here, and the loop below descends from this map's root
         // independently, so this check is what keeps a malformed map from reaching getChildNodeID.
-        if (nodeID.getDepth() >= kLeafDepth)
+        if (isLeafDepth(nodeID.getDepth()))
         {
             // LCOV_EXCL_START
             UNREACHABLE("xrpl::SHAMap::hasLeafNode : inner node at leaf depth");
@@ -849,8 +922,8 @@ SHAMap::verifyProofPath(UInt256 const& rootHash, UInt256 const& key, std::vector
                 // there. These nodes come off the wire, so a peer can still claim an inner one;
                 // reject it rather than passing this depth to selectBranch.
                 SOMETIMES(
-                    depth >= kLeafDepth, "xrpl::SHAMap::verifyProofPath : inner at leaf depth");
-                if (depth >= kLeafDepth)
+                    isLeafDepth(depth), "xrpl::SHAMap::verifyProofPath : inner at leaf depth");
+                if (isLeafDepth(depth))
                     return false;
 
                 auto const nodeId = SHAMapNodeID::createID(depth, key);
@@ -859,10 +932,9 @@ SHAMap::verifyProofPath(UInt256 const& rootHash, UInt256 const& key, std::vector
             }
             else
             {
-                // The hash chain up to rootHash only proves this leaf sits where the path claims,
-                // not that it is the leaf for `key`: a peer could substitute any other leaf whose
-                // subtree hashes to the same value at every level above it. Checking the terminal
-                // leaf's own key is what ties the proof to `key` specifically.
+                // The hash chain up to rootHash proves this leaf sits where the path claims. Any
+                // leaf whose subtree hashes the same at every level above satisfies that chain, so
+                // the terminal leaf's own key is what ties the proof to `key`.
                 if (leafKey(*node) != key)
                     return false;