1. Before You Get Started

1.1. What is Connext?

What Is Connext DDS?

RTI® Connext® DDS is a connectivity framework for building distributed applications with requirements for high performance and scalability. It includes these components:

  • An SDK that provides you with APIs to help you send and receive data using the communication patterns described in this documentation (see Next Steps). These APIs allow you to connect your own applications to other applications on the databus.

  • Tools that help you visualize your data and debug your distributed system.

  • Infrastructure Services that can perform dedicated functions in your system, such as recording, bridging, and persisting data.

1.2. Downloading Connext

If you haven’t already purchased a Connext bundle, you can follow this Getting Started guide with an evaluation bundle. To obtain an evaluation bundle, click the Free Trial button at https://www.rti.com/. Fill out the brief form, and you will receive an evaluation package shortly.

1.3. Installing Connext

To develop Python applications, you will need the following Connext bundles:

  • A host bundle that contains files such as documentation, the code generator, other tools, and infrastructure services executables. The host bundle is provided in a .run or .exe file that will run an installer.

    Host bundles are named:


    The <package_type> is usually pro.

    The <host_platform> depends on your development platform, such as x64Win64 for a 64-bit Windows® platform.

  • The Python API, required to develop Connext Python applications. The Python API is supported on Python 3.6 to 3.11, and on Linux® x64, Windows® x64, and macOS® x64.

    There are two ways to install it:

    • Install it from pypi.org. This installation method requires a license file when you run your application (see Setting Up a License).

    $ pip install rti.connext


    • Install it from your host installation directory. This method doesn’t require an internet connection or a license file.

    $ pip install rti.connext.activated -f <installdir>/resource/python_api

  • If you plan to develop C, C++, or Java applications or use add-on libraries you will also need a target bundle. See the C++ version of this Getting Started Guide for more information.

1.3.1. Installing a Host

The host bundle is an application; thus, it can be started from a GUI or command line. To install the host bundle, do either of the following:

1.3.2. Installing additional packages with a GUI

After you install the host bundle, you’ll have a tool called RTI Launcher. (See Starting Launcher, in the RTI Launcher User’s Manual.)

To install additional packages from the Launcher tool, open the Configuration tab, and select “Install RTI Packages.” This will open a dialog that allows you to select one or more .rtipkg files that you would like to install.

Install RTI Packages
RTI Package Installer

1.3.3. Installing additional packages from a Command Line

To install additional packages from the command line, type:

$ <installdir>/bin/rtipkginstall <path to rtipkg>

1.3.4. Paths Mentioned in Documentation

This documentation refers to the following directories, depending on your operating system:

$NDDSHOME This refers to the installation directory for Connext.

The default installation paths are:

  • Non-root user:

    /home/<your user name>/rti_connext_dds-<version>

  • Root user:


$NDDSHOME is an environment variable set to the installation path.

Sometimes this documentation uses <NDDSHOME> to refer to the installation path. Whenever you see <NDDSHOME> used in a path, replace it with $NDDSHOME for Linux or macOS systems, with %NDDSHOME% for Windows systems, or with your installation path.

1.4. Setting Up a License

Most installations require a license file to run the tools or features included in the Connext platform. If your distribution requires a license file, you will receive one from RTI via e-mail.

The easiest way to configure your license file is using Launcher, as shown below:

Configure License

If you do not want to use Launcher, you can also install a license by placing it in one of these two locations:

  • <installation directory>/rti_license.dat

  • <workspace directory>/rti_license.dat

The workspace directory is in this location by default, depending on your operating system:

/home/<your username>/rti_workspace/

A third way to install a license is to configure the environment variable RTI_LICENSE_FILE to point to your license file.

If you’re using the Connext Python API from PyPI, you will also need the license file to run your applications. You can copy the rti_license.dat file to the location where you run your application, set the RTI_LICENSE_FILE environment variable, or set its location in the DomainParticipantQos.

For more details on how to install a license file, see the License Management section in the RTI Connext Installation Guide.

1.5. Checking What is Installed

To find out what target libraries or add-ons you have installed, you can use the Launcher tool. See Starting Launcher, in the RTI Launcher User’s Manual. Once in Launcher, open the Configuration tab.

To check your Python API installation, run:

$ pip show rti.connext


$ pip show rti.connext.activated

1.6. Troubleshooting the Python API Installation

1.6.1. resource/python_api under Connext installation directory doesn’t exist

Make sure you have installed a host package. The evaluation installers don’t include rti.connext.activated. If you have an evaluation installer, install rti.connext (using the first method described in Installing Connext) and make sure your evaluation license file is accessible, for example by copying rti_license.dat to the current directory, where you launch your Python application.

1.6.2. pip install fails with ERROR: Could not find a version that satisfies the requirement rti.connext

If you get this error while installing the Python API with pip install, you may have to upgrade pip:

$ pip install --upgrade pip

If the installation still fails after that, make sure your Python version is supported (see Installing Connext).

1.6.3. pip install fails because I don’t have permissions to install packages

You can use a virtual environment to install packages without requiring admin privileges. To create a virtual environment, run the following commands:

$ python -m venv myvenv
$ . myvenv/bin/activate
$ pip install rti.connext

For more information about installing Python packages with pip, see the Python documentation: Virtual Environments and Packages.

1.7. Where Do I Get More Help?

Advanced installation help can be found in the RTI Connext DDS Installation Guide, which explains:

  • Installer command-line options

  • Controlling the location of the RTI Workspace directory

  • Additional license management options

  • Special backup of RTI libraries

  • How to uninstall Connext

Continue to Publish/Subscribe to start learning about the capabilities and features of Connext.

Additional documentation and user forums can be found on community.rti.com.