Setup references

You're probably on this page because you just saw an error like this one:

marimo raises this error when the setup cell references variables defined in other cells. In the example above, image is defined elsewhere in the notebook, and hence cannot be referenced.

Why can't I refer to variables?

The setup cell special: it runs before all other cells run, in order to provide symbols that top-level functions and classes can use. That's why it can't reference variables defined by other cells.

How do I fix this error?

Define all needed variables in the setup cell. Or, if this code does not need to run before all other cells (if you are not using top-level functions or classes), simply move your code to a regular cell.