Fieldstone

Description

Fieldstone is a content-modeling plugin for WordPress: build field groups, custom post types, and taxonomies from a clean visual editor, then read the values in your theme with simple template functions.

What makes Fieldstone different is where your data lives. Field values are stored in dedicated, indexed database tables — one row per post — instead of scattering two rows per field across wp_postmeta. That means faster queries, no postmeta bloat, and content you can actually query by field value.

At the same time, a postmeta mirror (on by default) keeps a plain copy of every value where the rest of the ecosystem expects it, so exports, backups, SEO plugins, and search plugins keep working untouched.

Features

• Visual field group editor — 24 field types: text, textarea, number, range, email, URL, password, select, checkbox, radio, button group, true/false, image, file, WYSIWYG, oEmbed, date, colour, link, icon picker, post link, and the layout types tab, accordion and message.
• Custom table storage — one indexed row per post; opt any field into a real database index.
• Postmeta mirror — full compatibility with WordPress export/import, backup plugins, SEO variables, and search plugins. A rebuild tool covers both directions.
• Location rules — target field groups by post type, page template, specific post/page, page type (front page, child pages…), post status, user role, taxonomy, attachment type, or menu item, combined with and/or logic.
• Fields wherever the content is — post screens, user profiles, taxonomy terms, attachments (including the media modal), and navigation menu items.
• Screen settings per group — put a group below the editor, above it, or in the side column; go seamless; place labels beside fields; choose where help text sits; order groups; hide WordPress panels you do not want; switch a group off without losing its data.
• Front-end forms — fstn_form() renders a group on the front of the site and accepts the submission, with validation, a honeypot and rate limiting. What the form targets is stored on the server, never in the page, so a submission cannot be edited into writing somewhere else.
• Shortcode — [fieldstone field="subtitle"] prints a value anywhere, always escaped.
• Duplicate, import and export — copy a group or a single field; export groups as JSON or as PHP that registers them from a file; import a JSON export back.
• Conditional logic — show or hide fields based on other fields’ values, enforced server-side.
• Validation — mark any field required, and set length, range, pattern or format rules with your own error message. Checked in the browser before saving and re-checked on the server, where an invalid field is reported without overwriting the value you already had.
• Import from Advanced Custom Fields — bring your existing ACF field groups across in one click, with a plain-English warning for anything that can’t map one to one. Deterministic mapping, no AI involved, and your ACF data is left untouched.
• Custom post types & taxonomies — register them from the same editor, with labels generated for you.
• Local JSON — every definition (field groups, post types, taxonomies) syncs to files in your theme for version control and deployments.
• REST API — opt field groups into the REST API; values appear on post responses and are writable with proper permissions.
• WP-CLI — wp fstn json status|sync, wp fstn mirror rebuild, wp fstn table status.
• Developer API — fstn_get_field(), fstn_the_field() (escaped by default), fstn_update_field(), fstn_register_field_group(), and a stable extension contract for custom field types.
• Generate with AI (optional) — describe a field group in plain language (“a recipe with ingredients, prep time and a photo”) and get the whole group drafted for review: correct types, choices, validation rules, and a location rule. Or open a group you have already started and ask for the fields it is missing — suggestions are added for review and never rename or replace what you built. Bring-your-own Anthropic API key; completely off until you add one. See “External services” below.

How to use

1. Go to Fieldstone → New Field Group, add your fields, and set a location rule (e.g. Post Type is Page).
2. Edit a matching post — your fields appear in a metabox. Fill them in and update.
3. Display the values in your theme with the template functions below.

Template functions

• fstn_get_field( $name, $context, $format ) — returns a field value (formatted by default). You escape the output.
• fstn_the_field( $name, $context ) — echoes the value already escaped with esc_html(). Best for plain text.
• fstn_get_fields( $context ) — returns all values for an object as a name => value array.
• fstn_update_field( $name, $value, $context ) — sanitizes and stores a value.

• fstn_delete_field( $name, $context ) — deletes a value.

  $context defaults to the current post in The Loop. It also accepts a post ID (123), 'option' for site-wide values, 'user_5' for a user, 'term_12' for a term, or a WP_Post / WP_User / WP_Term object.

Displaying each field type

Text / Textarea / Email — returns a string ('' when empty).

<p><?php fstn_the_field( 'headline' ); ?></p>

URL — returns an escaped URL string.

<a href="<?php echo esc_url( fstn_get_field( 'website' ) ); ?>">Visit</a>

Number — returns an int (or float when decimals are enabled), null when empty.

<?php $price = fstn_get_field( 'price' ); ?>
<span>$<?php echo esc_html( number_format( $price, 2 ) ); ?></span>

True / False — returns a bool.

<?php if ( fstn_get_field( 'is_featured' ) ) : ?><span class="badge">Featured</span><?php endif; ?>

Select / Radio — returns the chosen value as a string. A select with “Allow multiple” returns an array of strings.

<?php foreach ( (array) fstn_get_field( 'tags' ) as $tag ) : ?>
    <li><?php echo esc_html( $tag ); ?></li>
<?php endforeach; ?>

Checkbox — returns an array of the checked values.

<?php foreach ( fstn_get_field( 'features' ) as $feature ) : ?>
    <li><?php echo esc_html( $feature ); ?></li>
<?php endforeach; ?>

Image — return format is a per-field setting: array (default) returns id, url and alt; url returns the URL string; id returns the attachment ID.

<?php $img = fstn_get_field( 'headshot' ); ?>
<?php if ( $img ) : ?>
    <img src="<?php echo esc_url( $img['url'] ); ?>" alt="<?php echo esc_attr( $img['alt'] ); ?>" />
<?php endif; ?>

With return format id, use core helpers for responsive images: echo wp_get_attachment_image( fstn_get_field( 'headshot' ), 'large' );

File — same formats as image; the default array carries id, url and filename.

<?php $file = fstn_get_field( 'brochure' ); ?>
<a href="<?php echo esc_url( $file['url'] ); ?>" download><?php echo esc_html( $file['filename'] ); ?></a>

WYSIWYG — returns formatted HTML. Print with wp_kses_post().

<div class="content"><?php echo wp_kses_post( fstn_get_field( 'body' ) ); ?></div>

Date — returns a string in the field’s return format (default Y-m-d), null when empty.

<?php $date = fstn_get_field( 'event_date' ); ?>
<time datetime="<?php echo esc_attr( $date ); ?>"><?php echo esc_html( date_i18n( 'F j, Y', strtotime( $date ) ) ); ?></time>

Color — returns a hex string: #rrggbb, or #rrggbbaa when opacity is below 100%.

<span style="background: <?php echo esc_attr( fstn_get_field( 'brand_color' ) ); ?>;"></span>

Post Link (relationship) — returns a WP_Post object by default, or the post ID with return format id.

<?php $related = fstn_get_field( 'related_project' ); ?>
<?php if ( $related ) : ?>
    <a href="<?php echo esc_url( get_permalink( $related ) ); ?>"><?php echo esc_html( get_the_title( $related ) ); ?></a>
<?php endif; ?>

Reading many fields at once

<?php $f = fstn_get_fields(); ?>
<h2><?php echo esc_html( $f['full_name'] ?? '' ); ?></h2>

Options, users and terms

<?php echo esc_html( fstn_get_field( 'company_tagline', 'option' ) ); ?>
<?php echo esc_html( fstn_get_field( 'twitter', 'user_' . get_the_author_meta( 'ID' ) ) ); ?>
<?php echo esc_html( fstn_get_field( 'icon', 'term_' . $term_id ) ); ?>

External services

oEmbed providers

The oEmbed field turns a URL you paste into an embed, exactly as pasting the
same URL into the post editor does. When such a field is displayed, WordPress
asks that provider (YouTube, Vimeo, Spotify, X and the rest of its built-in
list) for the embed markup, and caches the answer. Only the URL saved in the
field is sent, and only to the provider that URL points at. If you never use an
oEmbed field, no such request is ever made.

Anthropic API

Fieldstone can optionally connect to the Anthropic API (api.anthropic.com) to power its two AI features: “Generate with AI” and “Suggest fields”.

• What is sent, and when: for Generate, only the field-group description you type into the Generate panel. For Suggest fields, only the title of the group you are editing and the label, name and type of the fields already in it. Both also send the plugin’s field-type instructions. A request is made only when you have saved your own Anthropic API key in Fieldstone → Settings AND click the Generate or Suggest fields button. No site content, posts, field values, user data, or analytics are ever sent, and nothing is sent in the background.
• Who provides it: the request goes directly from your server to Anthropic, PBC using your own API key — never through any Fieldstone server. Usage is billed by Anthropic to your account (typically a few cents per generation).
• Anthropic terms of service and privacy policy.

Without an API key, no AI features are shown and the plugin makes no external requests at all.