MobilityDB · estebanzimanyi · Jun 11, 2026 · Jul 2, 2026
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -239,6 +239,13 @@ endif ()
 
 add_custom_target(build_all_plugins)
 
+# Declared here so add_compile_definitions reaches all sibling nes-* targets.
+# nes-plugins/CMakeLists.txt re-declares the same option (no-op when cached).
+option(NES_ENABLE_MEOS "Enable MEOS plugin (requires libmeos installed on the system)" ON)
+if(NES_ENABLE_MEOS)
+    add_compile_definitions(NES_ENABLE_MEOS)
+endif()
+
 # Add target for common lib, which contains a minimal set
 # of shared functionality used by all components of nes
 file(GLOB NES_DIRECTORIES RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} "nes-*")

diff --git a/flake.nix b/flake.nix
@@ -54,6 +54,8 @@
           tbb
           python3
           openjdk21
+          paho-mqtt-c
+          paho-mqtt-cpp
         ]) ++ [ follyPkg antlr4Pkg ];
 
         antlr4Jar = pkgs.fetchurl {
@@ -244,6 +246,7 @@
             "-DNES_ENABLES_TESTS=ON"
             "-DCMAKE_MODULE_PATH=${libdwarfModule}/share/cmake/Modules"
             "-DANTLR4_JAR_LOCATION=${antlr4Jar}"
+            "-DNES_ENABLE_MEOS=OFF"
           ];
 
           enableParallelBuilding = true;
@@ -347,6 +350,7 @@
               "-DLLVM_DIR=${commonCmakeEnv.LLVM_DIR}"
               "-DANTLR4_JAR_LOCATION=${antlr4Jar}"
               "-DCMAKE_MODULE_PATH=${libdwarfModule}/share/cmake/Modules"
+              "-DNES_ENABLE_MEOS=OFF"
             ];
             shellHook = ''
               unset NES_PREBUILT_VCPKG_ROOT

diff --git a/nes-physical-operators/CMakeLists.txt b/nes-physical-operators/CMakeLists.txt
@@ -19,7 +19,11 @@ get_source(nes-physical-operators NES_PHYSICAL_OPERATORS_SOURCE_FILES)
 
 # Add Library
 add_library(nes-physical-operators ${NES_PHYSICAL_OPERATORS_SOURCE_FILES})
-target_link_libraries(nes-physical-operators PUBLIC nes-sources nes-sinks nes-nautilus nes-meos)
+if(NES_ENABLE_MEOS)
+    target_link_libraries(nes-physical-operators PUBLIC nes-sources nes-sinks nes-nautilus nes-meos)
+else()
+    target_link_libraries(nes-physical-operators PUBLIC nes-sources nes-sinks nes-nautilus)
+endif()
 target_include_directories(nes-physical-operators PUBLIC
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
         $<INSTALL_INTERFACE:include/nebulastream/>)

diff --git a/nes-physical-operators/src/Aggregation/Function/Meos/CMakeLists.txt b/nes-physical-operators/src/Aggregation/Function/Meos/CMakeLists.txt
@@ -10,5 +10,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+if(NES_ENABLE_MEOS)
 add_plugin(TemporalSequence AggregationPhysicalFunction nes-physical-operators TemporalSequenceAggregationPhysicalFunction.cpp)
 add_plugin(Var AggregationPhysicalFunction nes-physical-operators VarAggregationFunction.cpp)
+endif()
diff --git a/nes-physical-operators/src/Functions/Meos/CMakeLists.txt b/nes-physical-operators/src/Functions/Meos/CMakeLists.txt
@@ -10,9 +10,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+if(NES_ENABLE_MEOS)
 add_plugin(TemporalIntersects PhysicalFunction nes-physical-operators TemporalIntersectsPhysicalFunction.cpp)
 add_plugin(TemporalIntersectsGeometry PhysicalFunction nes-physical-operators TemporalIntersectsGeometryPhysicalFunction.cpp)
 add_plugin(TemporalAIntersectsGeometry PhysicalFunction nes-physical-operators TemporalAIntersectsGeometryPhysicalFunction.cpp)
 add_plugin(TemporalEContainsGeometry PhysicalFunction nes-physical-operators TemporalEContainsGeometryPhysicalFunction.cpp)
 add_plugin(TemporalEDWithinGeometry PhysicalFunction nes-physical-operators TemporalEDWithinGeometryPhysicalFunction.cpp)
 add_plugin(TemporalAtStBox PhysicalFunction nes-physical-operators TemporalAtStBoxPhysicalFunction.cpp)
+endif()
diff --git a/nes-plugins/CMakeLists.txt b/nes-plugins/CMakeLists.txt
@@ -20,33 +20,36 @@ activate_optional_plugin("Sources/TCPSource" ON)
 # Enable the Generator source plugin; required by systests and repl tests
 activate_optional_plugin("Sources/GeneratorSource" ON)
 activate_optional_plugin("Sinks/VoidSink" ON)
-activate_optional_plugin("Sources/MQTTSource" ON)
-activate_optional_plugin("Sinks/MQTTSink" ON)
-
-# MEOS is a dependency
-activate_optional_plugin("MEOS" ON)
-message(STATUS "Enable MEOS Plugin")
-
-# Detect the platform
-if (APPLE)
-    message(STATUS "Building on macOS")
-    # Set the include and library directories for Homebrew (macOS)
-    set(MEOS_INCLUDE_DIR "/opt/homebrew/include" CACHE PATH "Path to MEOS include directory")
-    set(MEOS_PLUGIN_INCLUDE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/include" CACHE PATH "Path to MEOS plugin include directory")
-    include_directories(SYSTEM ${MEOS_INCLUDE_DIR} ${MEOS_PLUGIN_INCLUDE_DIR})
-    include_directories(SYSTEM ${MEOS_INCLUDE_DIR} ${MEOS_PLUGIN_INCLUDE_DIR})
-    link_directories(${MEOS_LIBRARY_DIR} )
-
-else()
-    message(STATUS "Building on Linux")
-
-    # Default behavior for Linux
-    find_package(meos REQUIRED)
-    if(meos_FOUND)
-        message(STATUS "MEOS found: include=${meos_INCLUDE_DIR}, library=${meos}")
-        include_directories(SYSTEM ${meos_INCLUDE_DIR})
+option(NES_ENABLE_MQTT "Enable MQTT source and sink plugins (requires PahoMqttCpp)" ON)
+activate_optional_plugin("Sources/MQTTSource" ${NES_ENABLE_MQTT})
+activate_optional_plugin("Sinks/MQTTSink" ${NES_ENABLE_MQTT})
+
+option(NES_ENABLE_MEOS "Enable MEOS plugin (requires libmeos installed on the system)" ON)
+activate_optional_plugin("MEOS" ${NES_ENABLE_MEOS})
+if (NES_ENABLE_MEOS)
+    message(STATUS "Enable MEOS Plugin")
+
+    # Detect the platform
+    if (APPLE)
+        message(STATUS "Building on macOS")
+        # Set the include and library directories for Homebrew (macOS)
+        set(MEOS_INCLUDE_DIR "/opt/homebrew/include" CACHE PATH "Path to MEOS include directory")
+        set(MEOS_PLUGIN_INCLUDE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/include" CACHE PATH "Path to MEOS plugin include directory")
+        include_directories(SYSTEM ${MEOS_INCLUDE_DIR} ${MEOS_PLUGIN_INCLUDE_DIR})
+        include_directories(SYSTEM ${MEOS_INCLUDE_DIR} ${MEOS_PLUGIN_INCLUDE_DIR})
+        link_directories(${MEOS_LIBRARY_DIR} )
+
     else()
-        message(FATAL_ERROR "MEOS library not found")
+        message(STATUS "Building on Linux")
+
+        # Default behavior for Linux
+        find_package(meos REQUIRED)
+        if(meos_FOUND)
+            message(STATUS "MEOS found: include=${meos_INCLUDE_DIR}, library=${meos}")
+            include_directories(SYSTEM ${meos_INCLUDE_DIR})
+        else()
+            message(FATAL_ERROR "MEOS library not found")
+        endif()
     endif()
 endif()
 

diff --git a/nes-plugins/Sinks/MQTTSink/CMakeLists.txt b/nes-plugins/Sinks/MQTTSink/CMakeLists.txt
@@ -23,5 +23,10 @@ target_include_directories(mqtt_sink_validation_plugin_library
 )
 
 find_package(PahoMqttCpp CONFIG REQUIRED)
-target_link_libraries(mqtt_sink_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3-static)
-target_link_libraries(mqtt_sink_validation_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3-static)
+if(TARGET PahoMqttCpp::paho-mqttpp3-static)
+    target_link_libraries(mqtt_sink_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3-static)
+    target_link_libraries(mqtt_sink_validation_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3-static)
+else()
+    target_link_libraries(mqtt_sink_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3)
+    target_link_libraries(mqtt_sink_validation_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3)
+endif()
diff --git a/nes-plugins/Sources/MQTTSource/CMakeLists.txt b/nes-plugins/Sources/MQTTSource/CMakeLists.txt
@@ -23,5 +23,10 @@ target_include_directories(mqtt_source_validation_plugin_library
 )
 
 find_package(PahoMqttCpp CONFIG REQUIRED)
-target_link_libraries(mqtt_source_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3-static)
-target_link_libraries(mqtt_source_validation_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3-static)
+if(TARGET PahoMqttCpp::paho-mqttpp3-static)
+    target_link_libraries(mqtt_source_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3-static)
+    target_link_libraries(mqtt_source_validation_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3-static)
+else()
+    target_link_libraries(mqtt_source_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3)
+    target_link_libraries(mqtt_source_validation_plugin_library PRIVATE PahoMqttCpp::paho-mqttpp3)
+endif()
diff --git a/nes-query-optimizer/src/RewriteRules/LowerToPhysical/LowerToPhysicalWindowedAggregation.cpp b/nes-query-optimizer/src/RewriteRules/LowerToPhysical/LowerToPhysicalWindowedAggregation.cpp
@@ -54,8 +54,10 @@
 #include <QueryExecutionConfiguration.hpp>
 #include <RewriteRuleRegistry.hpp>
 // Special-case lowering for TEMPORAL_SEQUENCE (multi-input) aggregation
+#ifdef NES_ENABLE_MEOS
 #include <Operators/Windows/Aggregations/Meos/TemporalSequenceAggregationLogicalFunctionV2.hpp>
 #include <Aggregation/Function/Meos/TemporalSequenceAggregationPhysicalFunction.hpp>
+#endif
 
 namespace NES
 {
@@ -128,6 +130,7 @@ getAggregationPhysicalFunctions(const WindowedAggregationLogicalOperator& logica
         const auto name = descriptor->getName();
 
         // Custom lowering path for TEMPORAL_SEQUENCE: needs three field functions (lon, lat, ts)
+#ifdef NES_ENABLE_MEOS
         if (name == std::string_view("TemporalSequence"))
         {
             auto tsDescriptor = std::dynamic_pointer_cast<TemporalSequenceAggregationLogicalFunctionV2>(descriptor);
@@ -159,6 +162,7 @@ getAggregationPhysicalFunctions(const WindowedAggregationLogicalOperator& logica
             aggregationPhysicalFunctions.push_back(std::move(phys));
             continue;
         }
+#endif
 
         // Default path: use registry for single-input aggregations
         auto aggregationInputFunction = QueryCompilation::FunctionProvider::lowerFunction(descriptor->onField);

diff --git a/tools/codegen/.gitignore b/tools/codegen/.gitignore
@@ -0,0 +1,2 @@
+__pycache__/
+*.pyc
diff --git a/tools/codegen/README.md b/tools/codegen/README.md
@@ -0,0 +1,87 @@
+# MobilityNebula MEOS per-event operator codegen
+
+This directory contains the IDL-driven code generator for the canonical
+615-op per-event MEOS surface in MobilityNebula.
+
+## What it is
+
+The generator reads JSON descriptor files that describe each MEOS operator
+(name, SQL token, MEOS C function, argument types, return type) and emits
+the four C++ files that NES requires per operator:
+
+- `nes-logical-operators/include/Functions/Meos/<Name>LogicalFunction.hpp`
+- `nes-logical-operators/src/Functions/Meos/<Name>LogicalFunction.cpp`
+- `nes-physical-operators/include/Functions/Meos/<Name>PhysicalFunction.hpp`
+- `nes-physical-operators/src/Functions/Meos/<Name>PhysicalFunction.cpp`
+
+In addition to the per-operator files, the generator injects the
+CMakeLists.txt target lists, the AntlrSQL.g4 token rules, and the
+AntlrSQLQueryPlanCreator.cpp dispatch table so the full NES build stays
+consistent with the committed surface.
+
+## Pipeline
+
+```
+MobilityDB master
+    └─► MEOS-API run.py <headers>          # libclang extracts the C API
+        └─► meos-idl-master.json           # IDL: all public MEOS functions
+            └─► build_descriptor.py        # author a JSON descriptor family
+                └─► *-descriptor.json      # per-family operator list
+                    └─► gen_all.py         # orchestrates all 9 families
+                        └─► 4 C++ files per op + CMake/grammar/QPC glue
+```
+
+`meos-idl-master.json` committed here is a snapshot of the IDL generated
+from the current MobilityDB master.  Regenerate it via MEOS-API when the
+upstream C surface changes.
+
+## Descriptor families (9 total, 615 operators)
+
+| Descriptor file                         | Family                                      |
+|-----------------------------------------|---------------------------------------------|
+| `tfloat-transforms-descriptor.json`     | tfloat trig / abs / shift-scale             |
+| `numeric-descriptor.json`               | tint/tfloat/tbigint arithmetic, comparisons |
+| `spatial-predicates-descriptor.json`    | tgeo/tcbuffer/tnpoint/tpose spatial preds   |
+| `spatial-phasec-full-descriptor.json`   | full phase-C tgeo/tcbuffer/trgeometry preds |
+| `phasec-rest-descriptor.json`           | remaining phase-C spatial ops               |
+| `trgeo-descriptor.json`                 | trgeometry spatial predicates               |
+| `phasec-composed-descriptor.json`       | composed / multi-step spatial ops           |
+| `missing-ops-descriptor.json`           | 69 canonical ops not covered above          |
+| `canonical-new-ops-descriptor.json`     | 85 gap-fill ops closing the TARGET_SURFACE  |
+
+Intentionally excluded: bbox/topological operators (stbox/stbox,
+stbox/tspatial, tbox/tnumber families) and non-canonical per-type numeric
+two-temporal comparisons are out of scope for the 615-op canonical surface.
+
+## How to regenerate after a MobilityDB API change
+
+```sh
+python tools/codegen/gen_all.py --output-root <repo-root>
+```
+
+`<repo-root>` must be the MobilityNebula repository root (the directory
+that contains `nes-logical-operators/`).  The script writes all 2 460 C++
+files and updates CMakeLists.txt, AntlrSQL.g4, and
+AntlrSQLQueryPlanCreator.cpp in place.  Commit the result.
+
+## Files in this directory
+
+| File                          | Purpose                                           |
+|-------------------------------|---------------------------------------------------|
+| `codegen_nebula.py`           | Core emitter: templates for all 4 C++ file kinds  |
+| `gen_all.py`                  | Orchestrator: runs all 9 descriptor families      |
+| `codegen_aggregations.py`     | Supplementary generator for aggregation operators |
+| `build_descriptor.py`         | Helper: build a new descriptor from IDL entries   |
+| `codegen_input.example.json`  | Annotated example descriptor for new families     |
+| `meos-idl-master.json`        | Committed IDL snapshot from MobilityDB master     |
+| `build_local.sh`              | Local convenience wrapper for gen_all.py          |
+| `*-descriptor.json`           | The 9 operator family descriptors                 |
+
+## Drift guard
+
+`.github/workflows/codegen-drift-guard.yml` (added in the follow-up PR)
+runs on every pull request.  It executes `gen_all.py --output-root .` and
+then asserts `git diff --quiet`.  Any divergence between the committed
+operator files and the generator output fails the check and prints the
+diff stat.  To fix a drift failure, run the regeneration command above and
+commit the updated files.