Location rules: post type, post status, user role, page parent, page template, taxonomy, format — with OR groups and AND rules.
Conditional logic: show/hide fields based on other field values.
REST API: field values for posts exposed via /fieldforge/v1/fields/{id} with location-rule filtering.
Field validation: number enforces min/max, email validates format, URL validates format, text enforces maxlength.
Local JSON sync — field groups saved as JSON files in the theme for version control.
Field Group editor with drag-to-reorder fields, live field name auto-generation, type-specific settings panels, Repeater/Flexible Content sub-field editors, and dynamic location rule value dropdowns.
PHPUnit test suite covering all field type sanitize/save/load cycles and JSON importer logic.
GitHub Actions CI matrix on PHP 7.4, 8.0, 8.1, 8.2, 8.3.