wp-includes/rest-api.php:560Retrieves the URL to a REST endpoint.
$pathstringoptional''$schemestringoptional'rest'stringfunction rest_url( $path = '', $scheme = 'rest' ) { return get_rest_url( null, $path, $scheme );}Introduced in 4.4.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/rest-api.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.