Posit Workbench Extension in JupyterLab

The Posit Workbench extension for JupyterLab provides several useful tools when developing in JupyterLab sessions running on Posit Workbench.

JupyterLab 3 and JupyterLab 4 sessions require different extensions, but the functionality is the same. JupyterLab 4 requires pwb_jupyterlab and JupyterLab 3 requires workbench-jupyterlab.


If the Posit Workbench Extension for JupyterLab is not installed, please contact your administrator and have theme execute these installation instructions. Without the extension, JupyterLab sessions launch but without the additional features.

The extension provides:

JupyterLab Posit Workbench Extension icons

Proxying web servers

The Posit Workbench Extension includes a Proxied Servers view when selecting the extension from the Side Bar. This view contains a list of currently running web servers. Each item in this list includes the web server’s name and the port the process is running on. Selecting an item opens the server in a new browser tab.

The extension determines which servers to display by searching through your currently running processes for those with open and listening sockets. The extension excludes processes it expects and recognizes as non-development servers, such as R and Jupyter sessions. For R and Python processes, the extension represents the server’s name as the directory name.

We have ensured the following server types can be proxied correctly when using the extension in JupyterLab sessions. Other application types may work as expected.

  • Quarto
  • Shiny for Python
  • Shiny for R
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