1. A computer-implemented method, the method comprising: receiving, by a search system from a user device, a search query submitted by a user through a search interface of a website of a content provider; identifying, by the search system, a context file provided by the content provider, the context file identifying one or more document collections to be searched by the search system to obtain search results for users requesting searches through the search interface of the content provider; obtaining, by the search system, search results that satisfy the search query, wherein each search result of the one or more search results identifies a resource in the one or more document collections specified by the content provider in the context file; and providing the one or more search results to the user device for presentation to the user as a response to the search query.
5. The method of claim 1 , wherein the context file specifies a type-based filter for a particular resource type, the type-based filter indicating that search results that identify resources having the particular resource type should be filtered out of search results provided in response to a search query, and further comprising: removing, from the one or more search results, all search results that identify resources having the particular resource type.