Output a JSON Feed of posts in a zone

zones-json-feed.php

<?php

// This will be accessible at /feed/zones-json/
add_feed( 'zones-json', 'x_render_zones_json_feed' );

function x_render_zones_json_feed() {
	if ( function_exists( 'z_get_zone_query' ) ) {
		$query = z_get_zone_query( 'zone-name' );

		header('Content-type: application/json');
		echo json_encode( $query->posts ); // you'll obviously want to strip down the data that's output
	}
}