ash_phoenix/documentation/how_to/upgrade.md

Upgrading from 2.0 to 3.0

There are a few major changes in 3.0 that you should be aware of that affect AshPhoenix's behavior.

1. You don't need to pass in the domain to your forms.

2. Extra inputs are no longer accepted by actions. This means that if you were using custom form parameters, you may run into issues. There is a new option when constructing forms, skip_unknown_inputs: ["foo", "bar"] that allows you to skip these, but they don't currently apply to nested forms. If you need this, or encounter any issues, please open an issue.

3. When calling AshPhoenix.Form.params/1, for the same reasons as above, it will no longer return the hidden fields from the form. If you need these, you can add the hidden?: true option to AshPhoenix.Form.params/1.