SimpleFilterBackend

class SimpleFilterBackend(BaseFilterBackend):
    def get_schema_fields(self, view):
        return [coreapi.Field(
            name='query',
            location='query',
            required=False,
            type='string'
        )]

class MyViewSet(viewsets.ViewSet):
    filter_backends = (SimpleFilterBackend,)

    def list(self, request, *args, **kwargs):
        return Response({'hello': 'world'}, status.HTTP_200_OK)