A Web Annotation Protocol compliant "Search" API

Dear all,
I’m Luca De Santis of Net7, the company behind the Pundit annotation tool ( https://thepund.it <https://thepund.it/> ).
We are currently working on some updates of our tool. Amongst them, we are planning to develop an endpoint that supports, in read-only mode, the Web Annotation Protocol (WAP). Currently Pundit is compliant to the Web Annotation Data Model (well, quite compliant…).

Basically the APIs that we’d like to implement are:
1. the (filtered) retrieval of “a group” of annotations
2. the retrieval of a single annotation.

No problem for point 2, which is pretty clear.

Point 1, which corresponds in our use case to a “search for annotations”, is not completely clear to me. 
In fact, while the concept of “Annotation Containers” is very handy, I haven't seen a WAP compliant mode to pass parameters to filter results. 
Some examples of these parameters:
- the URI of the target document
- some conditions (e.g.: on author, date, etc).

Is there any standardization of the possible parameters to pass to filter annotations in a container? 
In particular we are planning to implement this method https://www.w3.org/TR/annotation-protocol/#representations-with-annotation-descriptions <https://www.w3.org/TR/annotation-protocol/#representations-with-annotation-descriptions> .

Other tools/services like Hypothes.is <http://hypothes.is/> or Europeana seem to have implemented a specific search endpoint (e.g. https://hypothes.is/api/search?uri=https://www.repubblica.it <https://hypothes.is/api/search?uri=https://www.repubblica.it> ), but if there is a clean and WAP complaint way to implement this feature I'd stick with it.

Any idea on that? Thanks in advance.

Regards,
Luca De Santis

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Luca De Santis / Chief Technology Officer
desantis@netseven.it <mailto:desantis@netseven.it> 
www.netseven.it <http://www.netseven.it/>
+39 050 55 25 74   
+39 335 7376 153
skype: lucadex



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