Frappe Custom DocTypes and Type Checking Setup Explained

When creating a new DocType in Frappe, you might notice that the Custom checkbox is non-interactable (read-only).

This happens if developer_mode is not active and the developer_mode parameter is set to 1 in the site_config.json file.

If the Custom setting is unchecked, the DocType will store document data in the codebase of the specified app.

Custom DocType with Type-Checking

When creating a non-custom DocType, you’ll notice a simple *.py file for form manipulation. However, type-checking is not enabled by default.

To enable type-checking by default, you need to modify the hooks.py file within your app, located at:

[yourFrappeBenchFolder]/apps/[yourAppName]/[yourAppName]/hooks.py

Add the following configuration:

# For type-checking
export_python_type_annotations = True

Finally, navigate to your DocType, update any field names, and save the DocType.