The REST namespace is wordpress-fetch/v1. Resources include sources, source actions, discovery, pre-save testing, metadata, dashboard, jobs, logs, OPML, groups, profiles, settings, and configuration export/validation/import. Browser calls use WordPress cookie authentication and X-WP-Nonce; external automation should use Application Passwords.
Important extension points:
wpfetch_request_headers( array $headers, string $url, ?Source $source )wpfetch_mapped_post( array $post, FeedItem $item, Source $source )wpfetch_post_imported( int $post_id, FeedItem $item, Source $source )
Normalized parsers return Domain\FeedItem; extensions should operate on normalized fields rather than RSS-specific XML paths. Mapping templates do not execute PHP.
Configuration export has schema version 1.0, excludes credentials, and can be validated before applying. Import requires an explicit confirm: true, never imports credentials, and creates sources disabled. OPML export is separate and intentionally contains only source-list information.