I think an issue was introduced regarding paging when getting topics for a category.
/c/{id}.json?page=0 doesn’t work anymore. We get a 400 errors with invalid_parameters.
We need to remove the page parameter when value is 0. page=1 is valid (but that is the 2nd page).
page=0 used to be valid.
page=0 is working when getting posts from topics.
I think it should be consistent and have support for page=0 everywhere for all types. It makes the use of your API easier.