Migration Guide#

This guide provides an overview of major (potentially breaking) changes and the steps to follow to update JupyterLite from one version to another.

0.3.0 to 0.4.0#


JupyterLite 0.4.0 is based on the JupyterLab 4.2 and Jupyter Notebook 7.2 packages.

Although no breaking changes are expected, this may affect the extensions you are using as they may rely on features added to JupyterLab 4.2 and Notebook 7.2.

See the JupyterLab and Notebook changelogs for more information:

API changes#


  • The signature of the currentChanged signal for the SingleWidgetShell has changed from ISignal<ISingleWidgetShell, void> to ISignal<ISingleWidgetShell, FocusTracker.IChangedArgs<Widget>>.

This follows this change in JupyterLab: Add IShell.currentChanged and notify commands based on it

@jupyterlite/contents package#

The TypeScript interface IEmscriptenNodeOps has changed. All methods now take IEmscriptenFSNode | IEmscriptenStream as input instead of only IEmscriptenFSNode. Classes implementing IEmscriptenNodeOps will need to be updated accordingly. See https://github.com/jupyterlite/jupyterlite/pull/1395 for an example implementation.

The TypeScript interface IDriveRequest has been removed. It has been replaced by the type definition TDriveRequest<T extends TDriveMethod>. This allows to have a more refined typing depending on the type of request. The same goes for the drive response type TDriveResponse<T extends TDriveMethod>. For example, a ‘readdir’ drive request would have the type TDriveRequest<'readdir'>, and its response would be of the type TDriveResponse<'readdir'>.

A new class DriveContentsProcessor is provided, which allows to perform drive requests using the jupyterlite contents manager. It can be used by Emscripten kernel authors in combination to extending the abstract ContentsAPI class in order to provide a custom way to implement file access from the kernel (e.g. bypassing the service worker approach).

0.2.0 to 0.3.0#


JupyterLite 0.3.0 is based on the JupyterLab 4.1 and Jupyter Notebook 7.1 packages.

Although no breaking changes are expected, this may affect the extensions you are using as they may rely on features added to JupyterLab 4.1 and Notebook 7.1.

jupyterlite metapackage#

Prior to JupyterLite 0.3.0, installing the jupyterlite metapackage would also install the JavaScript (Web Worker) kernel by default via the dependency on jupyterlite-javascript-kernel.

This dependency on jupyterlite-javascript-kernel has now been removed, so you may need to explicitely add jupyterlite-javascript-kernel to your build dependencies if you want to use that kernel.


As an alternative to jupyterlite-javascript-kernel, you may also want to use Xeus JavaScript, which currently offers more features and is generally more usable.


jupyterlite-javascript-kernel has now been moved to the jupyterlite-javascript-kernel repo.

Service Worker#

JupyterLite uses a Service Worker to make files and notebooks visible to the kernels, so they can be manipulated by the user via code in the notebook.

In previous versions, the Service Worker had caching enabled by default, and it was not possible to easily disable it.

The Service Worker cache was however the source of many issues when accessing files from a kernel, often giving errors to users, who would have to clear their cache to fix the issue.

In JupyterLite 0.3.0, the Service Worker cache is disabled by default, but it is still possible to enable it if needed.

To enable the Service Worker cache, add the enableServiceWorkerCache option to your jupyter-lite.json file. For example:

  "jupyter-lite-schema-version": 0,
  "jupyter-config-data": {
    "enableServiceWorkerCache": true

0.1.0 to 0.2.0#


JupyterLite 0.2.0 is based on the JupyterLab 4 and Jupyter Notebook 7 packages.

JupyterLab 4 comes with a couple of breaking changes which likely affect extensions.

If you were using JupyterLab 3 extensions in your JupyterLite deployment, you might have to update to a newer version of the extension that is compatible with JupyterLab 4.


For extensions authors, check out the extension migration guide in the JupyterLab documentation.

Jupyter Notebook 7#

In JupyterLite 0.1.x the Notebook interface was provided by RetroLab.

In JupyterLite 0.2.0, the Notebook interface is now provided by Jupyter Notebook 7

Jupyter Notebook 7 is the successor of RetroLab and the Classic Notebook, based on JupyterLab components.

This means the URL have also changed to be aligned with the ones provided by Jupyter Notebook 7:

  • /retro/consoles -> /consoles

  • /retro/edit -> /edit

  • /retro/notebooks -> /notebooks

  • /retro/tree -> /tree

jupyterlite metapackage#

In version 0.1.x, installing the jupyterlite metapackage would automatically install the Pyodide kernel by default, since the jupyterlite metapackage would depend on jupyterlite-pyodide-kernel.

In version 0.2.0 this is not the case anymore. You will need to install the jupyterlite-pyodide-kernel explicitly in your build environment alongside jupyterlite-core (the package providing the jupyter-lite CLI).

See the documentation for adding kernels to learn more.

Service Worker#

The service worker file name has been changed. In 0.1.0, it was service-worker-[hash].js with the hash computed by webpack, in 0.2.0 the hash is removed and the new file name is service-worker.js.

API changes#


  • The Mathjax addon was removed from the jupyterlite-core package. As a consequence the mathjaxConfig and fullMathjaxUrl options in jupyter-lite.json can be removed as they do not have any effect anymore.

    If you would like to use Mathjax 2, it’s possible to install jupyterlab-mathjax2. See the jupyter-renderers repository for more information.

    For reference, see the JupyterLab Pull Request that updated to Mathjax 3

@jupyterlite packages#

These API changes are only relevant if you are reusing @jupyterlite packages in downstream applications.

  • The IKernel interface exposed by @jupyterlite/kernels has a new get method to retrieve a running kernel by id.

0.1.0b19 to 0.1.0b20#


The static assets distributed via the jupyterlite-core package do not include the JavaScript kernel anymore.

Instead the JavaScript kernel is now distributed via the separate jupyterlite-javascript-kernel package.

If you would like to include the JavaScript kernel in your deployment you will have to first install it before building the JupyterLite site. For example with:

python -m pip install jupyterlite-javascript-kernel

Or add it to the LiteBuildConfig/federated_extensions config entry.

Currently the jupyterlite package still includes the JavaScript kernel via a dependency on jupyterlite-javascript-kernel. But this might change in a future version.

We recommend you start using the jupyterlite-core package directly for your deployments, and explicitly add more kernels such as jupyterlite-pyodide-kernel or jupyterlite-javascript-kernel.

0.1.0b18 to 0.1.0b19#


This release introduces a new jupyterlite-core package in addition to the existing jupyterlite package.

The jupyterlite-core package provides the core functionality for building JupyterLite websites CLI extension points. Currently it only includes a JavaScript kernel that runs in Web Worker. If you would like to include a Python kernel in your deployment yyou will have to first install it before building the JupyterLite site. For example with:

python -m pip install jupyterlite-pyodide-kernel

Or add it to the LiteBuildConfig/federated_extensions config entry.

The jupyterlite package currently provides a couple of shims as well as the Pyodide kernel for better compatibility with existing deployments.

We recommend you start using the jupyterlite-core package for your deployments, and additionally install a Python kernel such as jupyterlite-pyodide-kernel or a Xeus kernel.


The Pyodide kernel has been moved to its own repo: jupyterlite/pyodide-kernel

Currently it is still installed by default with jupyterlite for convenience, but it is not part of jupyterlite-core.

A consequence of this change is the renaming of the pyolite JavaScript packages:

  • @jupyterlite/pyolite-kernel -> @jupyterlite/pyodide-kernel

  • @jupyterlite/pyolite-kernel-extension -> @jupyterlite/pyodide-kernel-extension

Make sure to update your config if you were making use of litePluginSettings.

0.1.0b17 to 0.1.0b18#

The JavaScript kernel now runs in a Web Worker instead of an IFrame, to streamline how default kernels run in JupyterLite.

This might affect custom kernel authors extending the base JavaScriptKernel like https://github.com/jupyterlite/p5-kernel.

This was changed in the following PR: #711

0.1.0b16 to 0.1.0b17#

Use PipliteAddon.piplite_urls instead of LiteBuildConfig.piplite_urls#

If you were configuring the piplite_urls option (described in https://jupyterlite.readthedocs.io/en/latest/howto/python/wheels.html) to ship additional wheels at build time, this configuration option has now been moved from LiteBuildConfig.piplite_urls to PipliteAddon.piplite_urls.

If using a jupyter_lite_build.json file, the configuration should look like the following:

  "PipliteAddon": {
    "piplite_urls": ["url-to-wheel1", "url-to-wheel2", "..."]

This was changed in the following PR: #934