Feature summary
I added support to QuickCategories’ /batch/new/pagepile page to accept actions and title parameters via URL (GET request), in addition to the existing page_pile_id parameter. This allows external tools like Cat-a-lot to open QuickCategories with all necessary batch parameters prefilled via URL, simplifying batch creation.

Use case(s)
While working on the Cat-a-lot tool, I discovered that although page_pile_id could be passed to QuickCategories via URL, the actions (which specify category edits) and title (edit summary) parameters could not. This meant users or scripts had to manually fill these fields, complicating automation. Attempts to use POST were blocked by CORS policies when invoked from Wikimedia Commons. Therefore, enabling GET parameter support for actions and title provides a practical solution.

Benefits

• Improves automation for tools like Cat-a-lot by allowing all batch parameters to be set via URL, enabling seamless workflows.
• Reduces manual input errors and speeds up batch submissions.
• Makes QuickCategories more flexible and extensible for other external integrations or scripts.

I have raised a pull request implementing this feature: Add support for actions and title URL parameters in PagePile batch