# xslt on GET /w/api.php stops working

Calls to /w/api.php, query parameter xslt on Wikisource stopped working on November 30, 2025.

On November 30, 2025, support for the query parameter xslt on the /w/api.php endpoint was removed. Calls to /w/api.php using this parameter now fail. The change removed support for format=xml with an xslt stylesheet across Wikimedia projects.

## What to use instead

Stop sending an XSLT stylesheet and transform the XML or JSON output client-side instead.

- API: Wikisource (ar.wikisource.org)
- Kind: Parameter removal
- Announced: November 21, 2025
- Takes effect: November 30, 2025
- Calls after that day: fail
- Calls it hits: `/w/api.php`, `query parameter xslt`
- Source: [Announcement](https://lists.wikimedia.org/hyperkitty/list/mediawiki-api-announce@lists.wikimedia.org/message/5AX7UWAVVUNUSBOIRHMNOKWOZ5EZI3JX/)
- Verified: November 6, 2026, against Wikisource's own pages
- Page: https://www.okapi.bot/providers/wikisource/breaking-changes/xslt-on-get-w-api-php-stops-working/

## Wikisource's words

> Support for the format=xml&*xlst={stylesheet}* will be removed from Wikimedia projects by the end of November, 2025.

Okapi finds the calls this change hits in your repo and opens the pull request with the fix: https://github.com/apps/okapi-agent