I think that the correct URI might be the very similar plecoapi://x-callback-url/s?q=(search term) - I've found both versions listed in a few different places here and there, but only s?q works for me...
Thanks, I was able to add a plug-in to ctext.org to open Pleco and look-up words
Is there a more complete documentation of the URI features that are available? (perhaps a Reader that is able to use the ctext URIs would be useful!)
We haven't bothered documenting them explicitly since they've pretty much all been added at the request of various developers that want to link to us, but if you go to pleco.com/ipmanual/vershist.html and search for 'plecoapi' you should see them all in there.