Napari UI tracer


A plugin to help understand Napari UI components and check their source code definition

License MIT Python Version PyPI PyPI download month conda version conda download count tests codecov napari hub

A plugin to help understand Napari UI components and locate their code definition

This napari plugin was generated with Cookiecutter using @napari's cookiecutter-napari-plugin template.

GIF showing Napari UI tracer's functionality


You can install napari-ui-tracer via pip:

pip install napari-ui-tracer

Or via conda:

conda install -c conda-forge napari-ui-tracer

To install latest development version :

pip install git+


  1. Show the plugin inside the napari interface:

    • You can launch napari with the plugin visible running:

        napari -w napari-ui-tracer
    • Or select it from Plugins > Napari UI tracer widget

  2. Check the Enable Qt event filter checkbox:

    • Use Ctrl/Cmd + Mouse button right click to see the information available about any widget inside napari
    • An option to show objects documentation (object class docstring) can be used by checking the Show object documentation checkbox
  3. Check the Enable application events logging checkbox:

    • A log like information with the events generated when interacting with the application will appear
    • Some configuration options are available:
      • Stack depth: Stack depth to show. Default to 20
      • Allowed nested events: How many sub-emit nesting levels to show (i.e. events that get triggered by other events). Default to 0
  4. If you want to explore the related widget or event module source file, click the link in the output section of the plugin (the module file will open if you have a registered program to open such kind of file)


Contributions are very welcome. Pre-commit is used for formatting. Tests can be run with tox, please ensure the coverage at least stays the same before you submit a pull request.


Distributed under the terms of the MIT license, "napari-ui-tracer" is free and open source software


If you encounter any problems, please file an issue along with a detailed description.


  • 0.1.2

Last updated:

  • 13 April 2023

First released:

  • 14 March 2023


Supported data:

  • Information not submitted

Plugin type:

GitHub activity:

  • Stars: 4
  • Forks: 0
  • Issues + PRs: 0

Python versions supported:

Operating system:


  • qtpy (>=2.3.0)