2010/11/19 Nicolas Bregenzer nicolas.bregenzer@googlemail.com:

Hello, we are operating a search engine and would like to supplement our search suggestions with wikimedia open search: http://en.wikipedia.org/w/api.php?action=opensearch&search=%5BTERM] are there any limits in volume

No fixed limits, but you should include a descriptive User-Agent header with contact information in all of your API requests (always, regardless of volume) so we can contact you if you're causing problems.

or legally to what extend this service can be used ?

I don't think there are any legal restrictions on simple search results (as opposed to article content), but you should really ask the on-wiki folks about that; this is a technical list.

Roan Kattouw (Catrope)