7. Release Notes

7.1. Supported Platforms

Each ROS 2 version is built and tested with a specific Connext version to ensure functional and ABI compatibility. Using the versions in the table below guarantees that all libraries and tools work together as intended.

Table 7.1 ROS 2 and Connext Compatibility
ROS 2 Version	Connext Version
Lyrical	7.7.0
Kilted	7.3.0
Jazzy	6.0.1
Humble	6.0.1

7.2. Connext RMW

7.2.1. What’s new in the Lyrical Connext RMW (2026/05)

7.2.1.1. Lyrical Connext RMW is now compiled against Connext Professional 7.7.0

The Lyrical release of the Connext RMW has been updated to compile against Connext Professional 7.7.0.

7.2.1.2. Enabled topic and type name demangling by default, improving interoperability with Connext applications

Starting with the Lyrical release, the Connext RMW enables the dds.ros.demangle_topic_and_type_names property by default. This allows the RMW to announce demangled topic names as aliases, ensuring seamless out-of-the-box communication with Connext 7.7.0+ applications.

7.2.1.3. Debian package rti_connext_dds-7.7.0-ros now depends on official RTI Connext 7.7 Debian packages

In previous releases, the ROS 2-hosted Debian package (rti_connext_dds-x.y.z-ros) bundled all Connext Core Libraries required to compile the RMW. Now, this package uses APT dependencies on the standard Connext Debian packages.

This change streamlines the installation process, enabling simultaneous installation of both standard Connext and Connext ROS 2 Debian packages.

7.2.1.4. Introduced new variable to better manage publication mode selection

You can now configure how user topics are published by utilizing the new RMW_CONNEXT_USER_TOPICS_PUBLISH_MODE variable in the Connext RMW. For information on how to use this variable, see the Connext RMW GitHub readme.

This new variable replaces RMW_CONNEXT_USE_DEFAULT_PUBLISH_MODE, which has been deprecated in this release. See Deprecations and removals for more information.

7.2.1.5. Deprecations and removals

This section describes items that are deprecated or removed in the Lyrical release of the Connext RMW, compared to the Kilted release.

Deprecated means that the item is still supported in this release, but will be removed in a future release. Removed means that the item is discontinued or no longer supported.

Any deprecations or removals noted in RTI’s documentation serve as notice under the Real-Time Innovations, Inc., Maintenance Policy #4220 and/or any other agreements by and between RTI and customer regarding maintenance and support of RTI’s software. RTI’s current standard terms and support and maintenance policies are available at https://www.rti.com/terms.

7.2.1.5.1. RMW_CONNEXT_USE_DEFAULT_PUBLISH_MODE environment variable no longer supported

The RMW_CONNEXT_USE_DEFAULT_PUBLISH_MODE variable has been deprecated and will be removed in a future release. This variable previously determined the value of a DataWriter’s publish mode. If set in this release, it triggers a warning and is ignored.

RMW_CONNEXT_USE_DEFAULT_PUBLISH_MODE has been replaced by the new RMW_CONNEXT_USER_TOPICS_PUBLISH_MODE variable, which allows you to specify the default publish mode directly. See Introduced new variable to better manage publication mode selection for more information.

7.2.2. What’s fixed in the Lyrical Connext RMW (2026/05)

7.2.2.1. Serialized key size calculation error caused DDS sample writes to fail

The Connext RMW did not calculate the correct size for a serialized keyed sample. This error caused the middleware to reserve less memory than needed when writing a sample for certain types, which prevented the sample from being written.

The Connext RMW now uses the correct callback to calculate the size of a serialized keyed sample.

[RTI Issue ID ROS2-170]

7.3. RTI Connext Robotic Toolkit

7.3.1. What’s new in the RTI Connext Robotics Toolkit Lyrical 7.7.0 (2026/05)

RTI Connext Robotics Toolkit Lyrical packages are built on RTI Connext 7.7.0.