It's now possible to create ItemPage redirects. We should implement this functionality in Pywikibot too:
Parameters:
- from: Entity ID to make a redirect
- to: Entity ID to point the redirect to
- token: A 'csrf' token retrieved from action=query&meta=tokens
- bot: Mark this edit as bot (This URL flag will only be respected if the user belongs to the group "bot")
Example to turn Q11 into a redirect to Q12:
api.php?action=wbcreateredirect&from=Q11&to=Q12
This should be two parts: Part in site and part in page.
With T73979 a method to Page was added to create redirects, which doesn't directly use the site (only to save the page).