How to custom cell

I want to custom my own cell and implment it run logic. But I don’t know how to do it.
Could you give me a demo or a doc to implement it?

We don’t have very comprehensive docs for this right now. (Perhaps you could be the one to write a tutorial?)

Basically, you’ll need to write a JupyterLab extension that provides your custom cell class to the notebook. You can do this by providing an extension that overrides the default cell provider at You’d probably inherit from the notebook panel content factory at (which itself inherits from the notebook content factory at and override the createCodeCell method.

We’re happy to answer questions you may have.

Is this mean I can change exist cell behavior rather than create a new cell ?
So, I can write a JupyterLab extension to find code cell then change it behavior?

The extension I mention above would actually be the one supplying new code cells to JupyterLab wherever they were needed.

Hey @jasongrout I want try and do this too and will try and follow your steps listed, but just wondering if there any tutorials or docs that have been created in the last few months? ( I see the original post was from 8 months ago)

Having sifted through all the jupyterlab documents in the past 2 weeks, the most useful code examples so far for me has been


Oh wow, that looks like a really nice resource!

I don’t know of other comprehensive tutorials covering this case that have been written.

Any luck on this? I am trying to do the similar thing.