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VS Code Extension

The TethysL VSCode extension provides advanced editing capabilities for TethysL scripts.

Features include:

  • Complete mission validation, with error highlighting
  • Autocompletions, covering a good part of the language
  • Element information on mouse hover and with links to documentation
  • Script outline
  • Go-to-definition/references navigation:
    • From the use of an argument or output variable to its definition
    • From an argument definition to its usages
    • If the lrauv-application codebase is also available on the system, you can also quickly navigate to the C++ definition of behaviors and settings, units, and universals.
  • Source reformatting
  • Advanced:
    • Optionally, you can enable the automatic generation of XML (.tx extension) upon any successful compilation of the TethysL script. This, in particular, intended to facilitate inspection by users familiar with the XML format.
    • You can also generate TethysL from existing XML files. This is intended to facilitate the migration of existing mission scripts to the TethysL format.


You will only need the TethysL CLI installed on your system, in particular, with the tethysl program available via your $PATH environment variable. Please see the CLI section for instructions. (The extension will automatically call the TethysL LSP server included in the TethysL CLI program.)


In the future we may offer a more self-contained extension. At the moment this is not a priority as we presume the CLI is in general also to be used directly on the target system not only to compile .tl scripts but also for other various tasks, including use in makefiles (as part of preparations for vehicle deployments), documentation generation, XML validation, etc.

Using this extension

With the prerequisite in place (i.e., a functional tethysl program on your $PATH), just open a directory containing TethysL mission files in VSCode.

VSCode may automatically recognize the .tl file extension and offer you to install this extension from the VSCode marketplace. In general, you can directly use the Marketplace option in VSCode and enter "tethysl" in the search field:

Pick the latest version available, review the entry, click "Install", and enjoy.

Here's a screencast demonstrating some features initially implemented.

The extension is published at: