In #265 the ability to maps.wikimedia.org was added. Maybe since then the Terms of Use have changed, but they now say:
If you are developing an application that uses the Wikimedia Maps service, you must provide a valid HTTP User-Agent that includes your application, version, and sufficient information to easily contact you (e.g., your email address).
The following are prohibited on the Wikimedia Maps service:
Excessive downloading (such as downloading significant areas of tiles for later offline usage)
Accessing the service without a proper HTTP User-Agent or HTTP referer
Using the service without compliance with any license or copyright terms
I may have missed something obvious, but I can't see a way to specify a user-agent when adding a tile layer.
In #265 the ability to maps.wikimedia.org was added. Maybe since then the Terms of Use have changed, but they now say:
I may have missed something obvious, but I can't see a way to specify a user-agent when adding a tile layer.