apply_filters( 'rest_url_prefix', string $prefix ) Filters the REST URL prefix. ContentsParameters Source Related Used By Changelog User Contributed Notes Parameters $prefix (string) URL prefix. Default 'wp-json'. Top ↑Source File: wp-includes/rest-api.php View on Trac Top ↑Related Top ↑Used By Used By Used By Description wp-includes/rest-api.php: rest_get_url_prefix() Retrieves the URL prefix for any API resource. Top ↑Changelog Changelog Version Description 4.4.0 Introduced. Top ↑User Contributed Notes Skip to note 1 content You must log in to vote on the helpfulness of this noteVote results for this note: 0You must log in to vote on the helpfulness of this note Contributed by Farhan Noor — 2 years ago Flushing rewrite rules is required for new prefix to work. Simplest method is to visit Settings/Permalinks in your admin panel & Save Changes with existing settings. It will refresh your permalinks. You must log in before being able to contribute a note or feedback.