ROS X Introspection

Unified successor of the following libraries:

• ros_type_introspection
• ros_msg_parser
• ros2_introspection

The library compiles either using:

• ROS1 (catkin),
• ROS2 (colcon/ament) or
• without any ROS dependency (vanilla cmake).

To parse any ROS message at runtime, it requires:

• The name of the type (for instance “sensors_msgs/JointState”)
• The definition of the type (for instance this one),
• The raw memory buffer to be deserialized into individual key/values pairs.

The raw memory buffer is usually obtained by:

• rosbag::MessageInstance and Topic::ShapeShifter in ROS1.
• GenericSubscriber or rosbag2_storage::SerializedBagMessage on ROS2.
• MCAP.

Python binding

Compilation instructions:

cmake -S. -B build_python -DCMAKE_BUILD_TYPE=Release -DROSX_PYTHON_BINDINGS=ON
cmake --build build_python

If you have a rosbag (MCAP file) you can test it with this command

PYTHONPATH=build_python/python python3 python/mcap_ros_parser.py path_to_your_rosbag.mcap

Note that we are providing the folder where the dynamic library is using PYTHONPATH.

Changelog for package rosx_introspection

2.1.0 (2026-02-21)

• Fix multiple bugs in serialization, deserialization, and JSON handling

  • Fix missing throw in ROS_Deserializer::deserialize for unsupported types
  • Fix NanoCDR_Deserializer::deserializeByteSequence crash on empty sequences
  • Fix ROS_Serializer buffer resize logic and UB (const-cast, type-punning)
  • Fix Tree::find using &_root instead of _root.get() on unique_ptr
  • Fix msgpack pointer invalidation after vector resize for large messages
  • Fix blob detection in deserialize() (was restricted to OTHER type only)
  • Fix deserializeIntoJson blob skip not advancing the deserializer

  - Fix serializeFromJson: add JSON parse error checking, type-safe value reading with range validation, proper null handling for missing fields

  • Add complete ROS_Serializer implementation (serialize, serializeString, etc.)

  - Add comprehensive test coverage for all fixes Co-Authored-By: Claude Opus 4.6 <<noreply@anthropic.com>>

• Merge pull request #29 from agxeed/fix/time-duration-nsec-serialization fix: correct nsecs duration serialization

• Merge pull request #22 from amarburg/bugfix_ament_export_testing_dependencies Add sensor_msgs, geometry_msgs as ament dependencies when BUILD_TESTING is true

• Merge pull request #27 from jorritolthuis/msgpack_cpp Make convertToMsgPack() available in C++

• Merge pull request #30 from agxeed/fix/compiler-warnings fix: compiler warnings

• Merge pull request #32 from konsim83/feature/replace_rosbag2_cpp_with_rclcpp Use rclcpp type support instead of rosbag2_cpp

• fix: compiler warnings

• fix: correct nsecs duration serialization

• Make convertToMsgPack() available in C++

• Add sensor_msgs, geometry_msgs as ament dependencies when BUILD_TESTING

• remove ament_target_dependencies

• Contributors: Davide Faconti, Jorrit Olthuis, Konrad Simon, Rein Appeldoorn, admin

2.0.1 (2025-10-01)

• Merge pull request #21 from bryzhao/fix/scikit-build-core-compatibility Fix CMakeLists to support scikit-build-core installations
• Fix CMakeLists to support scikit-build-core installations
• Merge pull request #20 from nealtanner/bugfix/mac-compliation fix compilation errors on mac
• replace sprintf with snprintf
• inline vs constexpr
• Contributors: Bryan Zhao, Davide Faconti, Neal Tanner

2.0.0 (2025-09-24)

• optionally remove JSON support
• new formatting
• fix memory and add README
• add python binding
• NanoCDR
• Merge pull request #16 from traversaro/patch-1 Add missing include of functional header in message_definition_cache.cpp
• Fix issue #13
• Merge pull request #11 from valgur/bugfix/clang Fix ros_parser.cpp compilation failures on

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