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?