2140-dev · rustaceanrob · May 29, 2026 · May 29, 2026 · May 29, 2026
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -114,11 +114,6 @@ option(REDUCE_EXPORTS "Attempt to reduce exported symbols in the resulting execu
 option(CMAKE_COMPILE_WARNING_AS_ERROR "Treat compiler warnings as errors." OFF)
 option(WITH_CCACHE "Attempt to use ccache for compiling." ON)
 
-option(WITH_ZMQ "Enable ZMQ notifications." OFF)
-if(WITH_ZMQ)
-  find_package(ZeroMQ 4.0.0 MODULE REQUIRED)
-endif()
-
 option(WITH_EMBEDDED_ASMAP "Embed default ASMap data." ON)
 
 option(WITH_USDT "Enable tracepoints for Userspace, Statically Defined Tracing." OFF)
@@ -178,7 +173,6 @@ if(BUILD_FOR_FUZZING)
   set(BUILD_UTIL_CHAINSTATE OFF)
   set(BUILD_KERNEL_LIB OFF)
   set(BUILD_KERNEL_TEST OFF)
-  set(WITH_ZMQ OFF)
   set(WITH_EMBEDDED_ASMAP OFF)
   set(BUILD_TESTS OFF)
   set(BUILD_BENCH OFF)
@@ -585,7 +579,6 @@ message("  bitcoin-chainstate (experimental) ... ${BUILD_UTIL_CHAINSTATE}")
 message("  libbitcoinkernel (experimental) ..... ${BUILD_KERNEL_LIB}")
 message("  kernel-test (experimental) .......... ${BUILD_KERNEL_TEST}")
 message("Optional features:")
-message("  ZeroMQ .............................. ${WITH_ZMQ}")
 message("  Embedded ASMap ...................... ${WITH_EMBEDDED_ASMAP}")
 message("  USDT tracing ........................ ${WITH_USDT}")
 message("Tests:")

diff --git a/CMakePresets.json b/CMakePresets.json
@@ -13,8 +13,7 @@
       "architecture": "x64",
       "toolchainFile": "$env{VCPKG_ROOT}\\scripts\\buildsystems\\vcpkg.cmake",
       "cacheVariables": {
-        "VCPKG_TARGET_TRIPLET": "x64-windows",
-        "WITH_ZMQ": "ON"
+        "VCPKG_TARGET_TRIPLET": "x64-windows"
       }
     },
     {
@@ -29,8 +28,7 @@
       "architecture": "x64",
       "toolchainFile": "$env{VCPKG_ROOT}\\scripts\\buildsystems\\vcpkg.cmake",
       "cacheVariables": {
-        "VCPKG_TARGET_TRIPLET": "x64-windows-static",
-        "WITH_ZMQ": "ON"
+        "VCPKG_TARGET_TRIPLET": "x64-windows-static"
       }
     },
     {
@@ -74,8 +72,7 @@
         "BUILD_UTIL": "ON",
         "BUILD_UTIL_CHAINSTATE": "ON",
         "ENABLE_IPC": "ON",
-        "WITH_USDT": "ON",
-        "WITH_ZMQ": "ON"
+        "WITH_USDT": "ON"
       }
     }
   ]

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -147,7 +147,7 @@ the pull request affects. Valid areas are:
   - `mining` for changes to the mining code
   - `net` or `p2p` for changes to the peer-to-peer network code
   - `refactor` for structural changes that do not change behavior
-  - `rpc`, `rest` or `zmq` for changes to the RPC, REST or ZMQ APIs
+  - `rpc` or `rest` for changes to the RPC or REST APIs
   - `contrib` or `cli` for changes to the scripts and tools
   - `test`, `qa` or `ci` for changes to the unit tests, QA tests or CI code
   - `util` or `lib` for changes to the utils or libraries

diff --git a/ci/lint/requirements.txt b/ci/lint/requirements.txt
@@ -1,3 +1,2 @@
 lief==0.17.5
 mypy==1.19.1
-pyzmq==27.1.0
diff --git a/ci/test/00_setup_env_arm.sh b/ci/test/00_setup_env_arm.sh
@@ -8,7 +8,7 @@ export LC_ALL=C.UTF-8
 
 export HOST=arm-linux-gnueabihf
 export DPKG_ADD_ARCH="armhf"
-export PACKAGES="python3-zmq g++-arm-linux-gnueabihf libc6:armhf libstdc++6:armhf"
+export PACKAGES="g++-arm-linux-gnueabihf libc6:armhf libstdc++6:armhf"
 export CONTAINER_NAME=ci_arm_linux
 export CI_IMAGE_NAME_TAG="mirror.gcr.io/debian:trixie"  # Check that https://packages.debian.org/trixie/g++-arm-linux-gnueabihf (version 14.x, similar to guix) can cross-compile
 export CI_IMAGE_PLATFORM="linux/arm64"

diff --git a/ci/test/00_setup_env_mac_native.sh b/ci/test/00_setup_env_mac_native.sh
@@ -7,7 +7,7 @@
 export LC_ALL=C.UTF-8
 
 export CONTAINER_NAME="ci_mac_native"  # macos does not use a container, but the env var is needed for logging
-export PIP_PACKAGES="--break-system-packages pycapnp zmq"
+export PIP_PACKAGES="--break-system-packages pycapnp"
 export GOAL="install"
 export CMAKE_GENERATOR="Ninja"
 export CI_OS_NAME="macos"

diff --git a/ci/test/00_setup_env_native_alpine_musl.sh b/ci/test/00_setup_env_native_alpine_musl.sh
@@ -9,7 +9,7 @@ export LC_ALL=C.UTF-8
 export CONTAINER_NAME=ci_native_alpine_musl
 export CI_IMAGE_NAME_TAG="mirror.gcr.io/alpine:3.23"
 export CI_BASE_PACKAGES="build-base musl-dev pkgconf curl ccache make ninja git python3-dev py3-pip which patch xz procps rsync util-linux bison e2fsprogs cmake dash linux-headers"
-export PIP_PACKAGES="--break-system-packages pyzmq pycapnp"
+export PIP_PACKAGES="--break-system-packages pycapnp"
 export DEP_OPTS="DEBUG=1"
 export GOAL="install"
 export BITCOIN_CONFIG="\

diff --git a/ci/test/00_setup_env_native_asan.sh b/ci/test/00_setup_env_native_asan.sh
@@ -20,7 +20,7 @@ fi
 
 export CONTAINER_NAME=ci_native_asan
 export APT_LLVM_V="22"
-export PACKAGES="systemtap-sdt-dev clang-${APT_LLVM_V} llvm-${APT_LLVM_V} libclang-rt-${APT_LLVM_V}-dev mold python3-zmq libevent-dev libboost-dev libzmq3-dev ${BPFCC_PACKAGE} libcapnp-dev capnproto python3-pip"
+export PACKAGES="systemtap-sdt-dev clang-${APT_LLVM_V} llvm-${APT_LLVM_V} libclang-rt-${APT_LLVM_V}-dev mold libevent-dev libboost-dev ${BPFCC_PACKAGE} libcapnp-dev capnproto python3-pip"
 export PIP_PACKAGES="--break-system-packages pycapnp"
 export NO_DEPENDS=1
 export GOAL="install"

diff --git a/ci/test/00_setup_env_native_chimera_lto.sh b/ci/test/00_setup_env_native_chimera_lto.sh
@@ -12,7 +12,7 @@ export LC_ALL=C.UTF-8
 export CONTAINER_NAME=ci_native_chimera_musl
 export CI_IMAGE_NAME_TAG="mirror.gcr.io/chimeralinux/chimera"
 export CI_BASE_PACKAGES="ccache chimerautils chimerautils-extra clang cmake curl e2fsprogs git gmake gtar linux-headers ninja pkgconf procps python-devel python-pip rsync util-linux util-linux-lscpu xz"
-export PIP_PACKAGES="--break-system-packages pyzmq pycapnp"
+export PIP_PACKAGES="--break-system-packages pycapnp"
 export DEP_OPTS="build_CC=clang build_CXX=clang++ build_TAR=gtar AR=llvm-ar CC=clang CXX=clang++ NM=llvm-nm RANLIB=llvm-ranlib STRIP=llvm-strip"
 export GOAL="install"
 export BITCOIN_CONFIG="\

diff --git a/ci/test/00_setup_env_native_iwyu.sh b/ci/test/00_setup_env_native_iwyu.sh
@@ -10,7 +10,7 @@ export CI_IMAGE_NAME_TAG="mirror.gcr.io/debian:trixie"  # To build codegen, CMak
 export CONTAINER_NAME=ci_native_iwyu
 export IWYU_LLVM_V="22"
 export APT_LLVM_V="${IWYU_LLVM_V}"
-export PACKAGES="clang-${IWYU_LLVM_V} clang-format-${IWYU_LLVM_V} libclang-${IWYU_LLVM_V}-dev llvm-${IWYU_LLVM_V}-dev jq libevent-dev libboost-dev libzmq3-dev systemtap-sdt-dev libcapnp-dev capnproto"
+export PACKAGES="clang-${IWYU_LLVM_V} clang-format-${IWYU_LLVM_V} libclang-${IWYU_LLVM_V}-dev llvm-${IWYU_LLVM_V}-dev jq libevent-dev libboost-dev systemtap-sdt-dev libcapnp-dev capnproto"
 export NO_DEPENDS=1
 export RUN_UNIT_TESTS=false
 export RUN_FUNCTIONAL_TESTS=false

diff --git a/ci/test/00_setup_env_native_previous_releases.sh b/ci/test/00_setup_env_native_previous_releases.sh
@@ -9,7 +9,7 @@ export LC_ALL=C.UTF-8
 export CONTAINER_NAME=ci_native_previous_releases
 export CI_IMAGE_NAME_TAG="mirror.gcr.io/ubuntu:22.04"
 # Use minimum supported python3.10 and gcc-12, see doc/dependencies.md
-export PACKAGES="gcc-12 g++-12 python3-zmq"
+export PACKAGES="gcc-12 g++-12"
 export DEP_OPTS="CC=gcc-12 CXX=g++-12"
 export TEST_RUNNER_EXTRA="--previous-releases --coverage --extended --exclude feature_dbcrash"  # Run extended tests so that coverage does not fail, but exclude the very slow dbcrash
 export GOAL="install"

diff --git a/ci/test/00_setup_env_native_tidy.sh b/ci/test/00_setup_env_native_tidy.sh
@@ -10,7 +10,7 @@ export CI_IMAGE_NAME_TAG="mirror.gcr.io/ubuntu:24.04"
 export CONTAINER_NAME=ci_native_tidy
 export TIDY_LLVM_V="22"
 export APT_LLVM_V="${TIDY_LLVM_V}"
-export PACKAGES="clang-${TIDY_LLVM_V} libclang-${TIDY_LLVM_V}-dev llvm-${TIDY_LLVM_V}-dev libomp-${TIDY_LLVM_V}-dev clang-tidy-${TIDY_LLVM_V} jq libevent-dev libboost-dev libzmq3-dev systemtap-sdt-dev libcapnp-dev capnproto"
+export PACKAGES="clang-${TIDY_LLVM_V} libclang-${TIDY_LLVM_V}-dev llvm-${TIDY_LLVM_V}-dev libomp-${TIDY_LLVM_V}-dev clang-tidy-${TIDY_LLVM_V} jq libevent-dev libboost-dev systemtap-sdt-dev libcapnp-dev capnproto"
 export NO_DEPENDS=1
 export RUN_UNIT_TESTS=false
 export RUN_FUNCTIONAL_TESTS=false

diff --git a/ci/test/00_setup_env_native_tsan.sh b/ci/test/00_setup_env_native_tsan.sh
@@ -11,7 +11,7 @@ export CI_IMAGE_NAME_TAG="mirror.gcr.io/ubuntu:24.04"
 export APT_LLVM_V="22"
 LIBCXX_DIR="/cxx_build/"
 LIBCXX_FLAGS="-fsanitize=thread -nostdinc++ -nostdlib++ -isystem ${LIBCXX_DIR}include/c++/v1 -L${LIBCXX_DIR}lib -Wl,-rpath,${LIBCXX_DIR}lib -lc++ -lc++abi -lpthread -Wno-unused-command-line-argument"
-export PACKAGES="clang-${APT_LLVM_V} llvm-${APT_LLVM_V} llvm-${APT_LLVM_V}-dev libclang-${APT_LLVM_V}-dev libclang-rt-${APT_LLVM_V}-dev python3-zmq python3-pip"
+export PACKAGES="clang-${APT_LLVM_V} llvm-${APT_LLVM_V} llvm-${APT_LLVM_V}-dev libclang-${APT_LLVM_V}-dev libclang-rt-${APT_LLVM_V}-dev python3-pip"
 export PIP_PACKAGES="--break-system-packages pycapnp"
 export DEP_OPTS="CC=clang CXX=clang++ CXXFLAGS='${LIBCXX_FLAGS}'"
 export GOAL="install"

diff --git a/ci/test/00_setup_env_native_valgrind.sh b/ci/test/00_setup_env_native_valgrind.sh
@@ -8,7 +8,7 @@ export LC_ALL=C.UTF-8
 
 export CI_IMAGE_NAME_TAG="mirror.gcr.io/debian:trixie"
 export CONTAINER_NAME=ci_native_valgrind
-export PACKAGES="clang llvm libclang-rt-dev valgrind python3-zmq libevent-dev libboost-dev libzmq3-dev libcapnp-dev capnproto python3-pip"
+export PACKAGES="clang llvm libclang-rt-dev valgrind libevent-dev libboost-dev libcapnp-dev capnproto python3-pip"
 export PIP_PACKAGES="--break-system-packages pycapnp"
 export USE_VALGRIND=1
 export NO_DEPENDS=1

diff --git a/ci/test/00_setup_env_s390x.sh b/ci/test/00_setup_env_s390x.sh
@@ -7,7 +7,6 @@
 export LC_ALL=C.UTF-8
 
 export HOST=s390x-linux-gnu
-export PACKAGES="python3-zmq"
 export CONTAINER_NAME=ci_s390x
 export CI_IMAGE_NAME_TAG="mirror.gcr.io/debian:trixie"
 export CI_IMAGE_PLATFORM="linux/s390x"

diff --git a/ci/test/03_test_script.sh b/ci/test/03_test_script.sh
@@ -203,7 +203,7 @@ fi
 
 if [[ "${RUN_IWYU}" == true ]]; then
   # TODO: Consider enforcing IWYU across the entire codebase.
-  FILES_WITH_ENFORCED_IWYU="/src/(((crypto|index|kernel|primitives|univalue/(lib|test)|util|zmq)/.*|bench/(block_assemble|connectblock)|common/license_info|node/(blockstorage|interfaces|miner|mining_args|utxo_snapshot)|rpc/mining|clientversion|core_io|signet|init)\\.cpp)"
+  FILES_WITH_ENFORCED_IWYU="/src/(((crypto|index|kernel|primitives|univalue/(lib|test)|util)/.*|bench/(block_assemble|connectblock)|common/license_info|node/(blockstorage|interfaces|miner|mining_args|utxo_snapshot)|rpc/mining|clientversion|core_io|signet|init)\\.cpp)"
   jq --arg patterns "$FILES_WITH_ENFORCED_IWYU" 'map(select(.file | test($patterns)))' "${BASE_BUILD_DIR}/compile_commands.json" > "${BASE_BUILD_DIR}/compile_commands_iwyu_errors.json"
   jq --arg patterns "$FILES_WITH_ENFORCED_IWYU" 'map(select(.file | test($patterns) | not))' "${BASE_BUILD_DIR}/compile_commands.json" > "${BASE_BUILD_DIR}/compile_commands_iwyu_warnings.json"
 

diff --git a/cmake/module/FindZeroMQ.cmake b/cmake/module/FindZeroMQ.cmake
diff --git a/contrib/zmq/zmq_sub.py b/contrib/zmq/zmq_sub.py
diff --git a/depends/Makefile b/depends/Makefile
@@ -35,7 +35,6 @@ WORK_PATH = $(BASEDIR)/work
 BASE_CACHE ?= $(BASEDIR)/built
 SDK_PATH ?= $(BASEDIR)/SDKs
 NO_BOOST ?=
-NO_ZMQ ?=
 NO_USDT ?=
 LTO ?=
 FALLBACK_DOWNLOAD_PATH ?= https://bitcoincore.org/depends-sources
@@ -148,16 +147,11 @@ $(host_arch)_$(host_os)_id:=$(shell env CC='$(host_CC)' C_STANDARD='$(C_STANDARD
 
 boost_packages_$(NO_BOOST) = $(boost_packages)
 
-zmq_packages_$(NO_ZMQ) = $(zmq_packages)
 usdt_packages_$(NO_USDT) = $(usdt_$(host_os)_packages)
 
 packages += $($(host_arch)_$(host_os)_packages) $($(host_os)_packages) $(boost_packages_) $(ipc_packages) $(usdt_packages_)
 native_packages += $($(host_arch)_$(host_os)_native_packages) $($(host_os)_native_packages) $(multiprocess_native_packages)
 
-ifneq ($(zmq_packages_),)
-packages += $(zmq_packages)
-endif
-
 all_packages = $(packages) $(native_packages)
 
 meta_depends = Makefile config.guess config.sub funcs.mk builders/default.mk hosts/default.mk hosts/$(host_os).mk builders/$(build_os).mk
@@ -208,7 +202,6 @@ $(host_prefix)/toolchain.cmake : toolchain.cmake.in $(host_prefix)/.stamp_$(fina
             -e 's|@LDFLAGS@|$(strip $(host_LDFLAGS))|' \
             -e 's|@LDFLAGS_RELEASE@|$(strip $(host_release_LDFLAGS))|' \
             -e 's|@LDFLAGS_DEBUG@|$(strip $(host_debug_LDFLAGS))|' \
-            -e 's|@zmq_packages@|$(zmq_packages_)|' \
             -e 's|@usdt_packages@|$(usdt_packages_)|' \
             -e 's|@ipc_packages@|$(ipc_packages)|' \
             $< > $@

diff --git a/depends/README.md b/depends/README.md
@@ -78,7 +78,6 @@ The following can be set when running make: `make FOO=bar`
 - `C_STANDARD`: Set the C standard version used. Defaults to `c11`.
 - `CXX_STANDARD`: Set the C++ standard version used. Defaults to `c++20`.
 - `NO_BOOST`: Don’t download/build/cache Boost
-- `NO_ZMQ`: Don’t download/build/cache packages needed for enabling ZeroMQ
 - `NO_USDT`: Don’t download/build/cache packages needed for enabling USDT tracepoints
 - `DEBUG`: Disable some optimizations and enable more runtime checking
 - `HOST_ID_SALT`: Optional salt to use when generating host package ids
@@ -88,7 +87,7 @@ The following can be set when running make: `make FOO=bar`
   of build error. After successful build log files are moved along with package archives
 - `LTO`: Enable options needed for LTO. Does not add `-flto` related options to *FLAGS.
 
-If some packages are not built (e.g. `make NO_ZMQ=1`), the appropriate CMake cache
+If some packages are not built (e.g. `make NO_BOOST=1`), the appropriate CMake cache
 variables will be set when generating the Bitcoin Core buildsystem.
 
 ## Compiler Configuration

diff --git a/depends/packages/packages.mk b/depends/packages/packages.mk
@@ -2,8 +2,6 @@ packages:=
 
 boost_packages = boost
 
-zmq_packages=zeromq
-
 ipc_packages = capnp
 multiprocess_native_packages = native_libmultiprocess native_capnp