WP rest api v2 posts filter by ‘search’ & ‘category_name’ not working

The filter parameter was removed as part of WP 4.7, to get the results you expect you’ll need to change

http://examples.com/wp-json/wp/v2/posts?filter[category_name]=uncategorize&per_page=30&order=asc&search=hello

to

http://examples.com/wp-json/wp/v2/posts?categories=1&per_page=30&order=asc&search=hello

Make sure to change categories=0 to whatever uncategorised‘s tag_ID is.

If you’d like to restore the Filter parameter, I would recommend this plugin: https://github.com/WP-API/rest-filter