DataAnalyticsEngineering · sanathkeshav · Aug 12, 2026 · Aug 11, 2026 · Aug 11, 2026 · Aug 11, 2026
diff --git a/.github/workflows/test_pyfans.yaml b/.github/workflows/test_pyfans.yaml
@@ -24,9 +24,6 @@ jobs:
     - name: Checkout repository
       uses: actions/checkout@v7
 
-    - name: Generate build directory
-      run: mkdir -p ${{ env.FANS_BUILD_DIR }}
-
     - name: Install dependencies
       run: |
         apt update
@@ -43,11 +40,17 @@ jobs:
         . .venv/bin/activate
         pip install micro-manager-precice
 
-    - name: Configure
-      working-directory: ${{ env.FANS_BUILD_DIR }}
+    - name: Build and install FANS
+      run: |
+        cmake -S . -B ${{ env.FANS_BUILD_DIR }}
+        cmake --build ${{ env.FANS_BUILD_DIR }} -j
+        cmake --install ${{ env.FANS_BUILD_DIR }}
+        ldconfig
+
+    - name: Install pyfans against it
       run: |
-        cmake .. -DFANS_LIBRARY_FOR_MICRO_MANAGER=ON
-        make
+        . .venv/bin/activate
+        pip install ./pyfans
 
     - name: Run a dummy macro-micro coupling test
       run: |

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # FANS Changelog
 
+## latest
+
+- Build pyFANS as a standalone nanobind project against an installed FANS, so FANS itself no longer depends on Python [#155](https://github.com/DataAnalyticsEngineering/FANS/pull/155)
+
 ## v0.8.0
 
 - Make PyFANS installable (also with pixi build) [#152](https://github.com/DataAnalyticsEngineering/FANS/pull/152)

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -90,21 +90,12 @@ endif ()
 
 set(HDF5_PREFER_PARALLEL TRUE)
 find_package(HDF5 REQUIRED COMPONENTS C CXX)
-
 find_package(Eigen3 REQUIRED)
-
 find_package(MPI REQUIRED)
-
 find_package(FFTW3 REQUIRED COMPONENTS DOUBLE MPI)
-
-option(FANS_LIBRARY_FOR_MICRO_MANAGER "Building FANS as a library to be used by the Micro Manager." OFF)
-
-if (FANS_LIBRARY_FOR_MICRO_MANAGER)
-    set(PYBIND11_FINDPYTHON ON)
-    find_package(pybind11 CONFIG REQUIRED)
-endif()
 find_package(nlohmann_json REQUIRED)
 find_package(spdlog CONFIG REQUIRED)
+
 # ##############################################################################
 # TARGETS
 # ##############################################################################
@@ -133,42 +124,16 @@ add_custom_command(
         COMMENT "Create a symlink for FANS executable to ${CMAKE_CURRENT_SOURCE_DIR}/test/"
 )
 
-if (FANS_LIBRARY_FOR_MICRO_MANAGER)
-    add_subdirectory(pyfans)
-endif ()
-
 # ##############################################################################
 # HEADERS
 # ##############################################################################
 
 target_include_directories(FANS_FANS PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>)
 
-# TODO: when creating a shared library in the future, maybe create one single
-# FANS.h header that consuming projects can use
-set_property(TARGET FANS_FANS PROPERTY PUBLIC_HEADER
-        include/general.h
-        include/logging.h
-        include/matmodel.h
-        include/LargeStrainMechModel.h
-        include/MaterialManager.h
-        include/reader.h
-        include/solverCG.h
-        include/solverFP.h
-        include/solver.h
-        include/setup.h
-        include/mixedBCs.h
-
-        include/material_models/thermal/LinearThermal.h
-        include/material_models/thermal/GBDiffusion.h
-
-        include/material_models/small_strain/LinearElastic.h
-        include/material_models/small_strain/PseudoPlastic.h
-        include/material_models/small_strain/J2Plasticity.h
-        include/material_models/small_strain/J2PlasticityNew.h
-
-        include/material_models/large_strain/SaintVenantKirchhoff.h
-        include/material_models/large_strain/CompressibleNeoHookean.h
-        include/material_models/large_strain/FiniteStrainJ2Plasticity.h
+install(
+        DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/include/
+        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/FANS
+        FILES_MATCHING PATTERN "*.h"
 )
 
 # version.h is generated and added to the build include directory
@@ -182,42 +147,25 @@ target_include_directories(FANS_main PRIVATE "${PROJECT_BINARY_DIR}/include")
 # SOURCES
 # ##############################################################################
 
-target_sources(FANS_FANS PRIVATE
-        src/reader.cpp
-)
-
-target_sources(FANS_main PRIVATE
-        src/main.cpp
-)
+target_sources(FANS_FANS PRIVATE src/reader.cpp)
+target_sources(FANS_main PRIVATE src/main.cpp)
 
 # ##############################################################################
 # LINKING
 # ##############################################################################
 
 target_link_libraries(FANS_FANS PRIVATE m)
 
-# TODO: when switching to a newer CMake version this can all be done by one
-# call to target_link_libraries(FANS_FANS PUBLIC HDF5::HDF5). But CMake 3.16
-# does not yet support this.
-target_include_directories(FANS_FANS PRIVATE ${HDF5_INCLUDE_DIRS})
-target_link_libraries(FANS_FANS PUBLIC ${HDF5_C_LIBRARIES})
-target_link_libraries(FANS_FANS PUBLIC ${HDF5_CXX_LIBRARIES})
-target_compile_definitions(FANS_FANS PUBLIC ${HDF5_DEFINITIONS})
+target_link_libraries(FANS_FANS PUBLIC HDF5::HDF5)
 if (HDF5_IS_PARALLEL)
     target_compile_definitions(FANS_FANS PUBLIC H5_HAVE_PARALLEL)
 endif ()
-
 target_link_libraries(FANS_FANS PUBLIC MPI::MPI_CXX)
-
-target_include_directories(FANS_FANS PRIVATE ${FFTW3_INCLUDE_DIRS})
-target_link_libraries(FANS_FANS PUBLIC ${FFTW3_LIBRARIES})
-target_compile_definitions(FANS_FANS PUBLIC ${FFTW3_DEFINITIONS})
-
+target_link_libraries(FANS_FANS PUBLIC fftw3::double::serial fftw3::double::mpi)
 target_link_libraries(FANS_FANS PUBLIC Eigen3::Eigen)
 target_link_libraries(FANS_FANS PUBLIC nlohmann_json::nlohmann_json)
 target_link_libraries(FANS_FANS PUBLIC spdlog::spdlog)
 
-target_include_directories(FANS_main PRIVATE ${HDF5_INCLUDE_DIRS} ${FFTW3_INCLUDE_DIRS})
 target_link_libraries(FANS_main PRIVATE FANS::FANS)
 
 # ##############################################################################
@@ -237,40 +185,28 @@ install(
         EXPORT FANS
         LIBRARY
         DESTINATION ${CMAKE_INSTALL_LIBDIR}
-        COMPONENT FANS_Runtime
-        NAMELINK_COMPONENT FANS_Development
         ARCHIVE
         DESTINATION ${CMAKE_INSTALL_LIBDIR}
-        COMPONENT FANS_Development
         INCLUDES
         DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/FANS
-        PUBLIC_HEADER
-        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/FANS
-        COMPONENT FANS_Development
-        PRIVATE_HEADER
-        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/FANS
-        COMPONENT FANS_Development
 )
 
 install(
         TARGETS FANS_main
         RUNTIME
         DESTINATION ${CMAKE_INSTALL_BINDIR}
-        COMPONENT FANS_Runtime
 )
 
 install(
         EXPORT FANS
         DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/FANS
         NAMESPACE FANS::
         FILE FANSTargets.cmake
-        COMPONENT FANS_Development
 )
 
 install(
         FILES ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules/FindFFTW3.cmake
         DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/FANS/modules
-        COMPONENT FANS_Development
 )
 
 write_basic_package_version_file(
@@ -288,7 +224,6 @@ install(
         FILES ${CMAKE_CURRENT_BINARY_DIR}/FANSConfig.cmake
         ${CMAKE_CURRENT_BINARY_DIR}/FANSConfigVersion.cmake
         DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/FANS
-        COMPONENT FANS_Development
 )
 
 # ##############################################################################
@@ -303,15 +238,3 @@ if (FANS_ENABLE_TESTING)
     enable_testing()
     add_subdirectory(test)
 endif ()
-
-# ##############################################################################
-# PACKAGING
-# ##############################################################################
-
-if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
-    set(FANS_ENABLE_PACKAGING_DEFAULT ON)
-endif ()
-option(FANS_ENABLE_PACKAGING "Enable creation of Debian packages" ${FANS_ENABLE_PACKAGING_DEFAULT})
-if (FANS_ENABLE_PACKAGING)
-    add_subdirectory(cmake/packaging)
-endif ()
diff --git a/README.md b/README.md
@@ -196,7 +196,6 @@ cd ../test
 | `CMAKE_INTERPROCEDURAL_OPTIMIZATION` | Enable link-time optimization (LTO) | `ON` (if supported) |
 | `FANS_BUILD_STATIC` | Build static library | `OFF` |
 | `CMAKE_INSTALL_PREFIX` | Installation directory | System default |
-| `FANS_LIBRARY_FOR_MICRO_MANAGER` | Build Python bindings using Pybind11 (needed) | `OFF` |
 | `FANS_ENABLE_SANITIZERS` | Enable runtime sanitizers (AddressSanitizer and LeakSanitizer) for memory debugging | `OFF` |
 
 ---

diff --git a/cmake/FANSConfig.cmake.in b/cmake/FANSConfig.cmake.in
@@ -14,12 +14,13 @@ include(CMakeFindDependencyMacro)
 set(HDF5_ENABLE_PARALLEL ON)
 set(HDF5_PREFER_PARALLEL ON)
 find_dependency(HDF5 REQUIRED COMPONENTS C CXX)
-if (NOT HDF5_C_IS_PARALLEL)
-    message(FATAL_ERROR "Parallel HDF5 implementation (mpi) required but not found!")
+if (DEFINED HDF5_C_IS_PARALLEL AND NOT HDF5_C_IS_PARALLEL)
+    message(WARNING "HDF5 does not look MPI-parallel; FANS needs a parallel HDF5 at runtime.")
 endif()
 find_dependency(Eigen3)
 find_dependency(MPI)
 find_dependency(FFTW3 COMPONENTS DOUBLE MPI)
+find_dependency(nlohmann_json)
 find_dependency(spdlog CONFIG)
 
 set(CMAKE_MODULE_PATH "${CMAKE_MODULE_PATH_save}")

diff --git a/cmake/packaging/CMakeLists.txt b/cmake/packaging/CMakeLists.txt
diff --git a/docker/Dockerfile b/docker/Dockerfile
@@ -30,10 +30,9 @@ RUN apt-get update -qq && apt-get install -y --no-install-recommends \
 # Build basics
     software-properties-common \
     build-essential \
-# CMake + git for the CI checkout + file for CPack
+# CMake + git for the CI checkout
     cmake \
     git \
-    file \
 # FANS dependencies \
     libhdf5-dev \
     libhdf5-openmpi-dev \
@@ -43,9 +42,8 @@ RUN apt-get update -qq && apt-get install -y --no-install-recommends \
     libfftw3-mpi-dev \
     nlohmann-json3-dev \
     libspdlog-dev \
-# Required for preCICE Micro Manager Python bindings
+# Required for building pyfans
     python3-dev \
-    pybind11-dev \
 # Clean up
     && apt-get clean \
     && apt-get autoremove --purge -y \

diff --git a/docs/ReleaseGuide.md b/docs/ReleaseGuide.md
@@ -6,7 +6,7 @@ The release of the `FANS` repository is made directly from a release branch call
 
 1. Create a branch called `FANS-v1.2.3` from the latest commit of the `develop` branch.
 
-2. Bump the version in the `CHANGELOG.md`, the base `CMakeLists.txt`, and in the `pixi.toml` on the branch `FANS-v1.2.3`.
+2. Bump the version in the `CHANGELOG.md`, the base `CMakeLists.txt`, the base `pixi.toml`, and in the `pyfans/pyproject.toml` on the branch `FANS-v1.2.3`.
 
 3. Assuming you have Pixi installed, run the command `pixi lock` in the repository root to update the `pixi.lock` file. Then commit and push the `FANS-v1.2.3` branch to remote.