KUROFUNE LINK

KUROFUNE LINK works with KUROFUNE, a separate, paid SEO service. It does two things on the posts of your site:

1. Related posts. It adds a short list of related posts from the same site after the body of each post, so that new articles also receive links from older ones. KUROFUNE decides which posts are related, using its analysis of your articles, and delivers only pairs of post IDs. The plugin renders the list from your own WordPress data (titles, permalinks and featured images).
2. Keeping KUROFUNE’s parts up to date. Posts written or rewritten with KUROFUNE can contain three kinds of marked parts: recommendation links (affiliate or product links you registered in KUROFUNE), call-to-action (CTA) blocks, and author cards. When you change one of them in KUROFUNE, KUROFUNE delivers the new link URL or block HTML, and the plugin shows it in place of the old one in every post that contains that marked part.

• The post content is never modified. Both happen only when a single post is displayed, so deactivating the plugin brings back exactly what is saved in each post.
• Posts that the body already links to are left out of the related posts. Only published posts without a password are shown.
• The number of related posts (default 6) and the heading can be changed under Settings > KUROFUNE LINK, and the related-post list can be turned off there. That setting does not stop the updates of marked parts; deactivate the plugin to stop them.
• Delivered HTML is checked with WordPress’s own HTML filter (kses) when it is received, and anything that does not pass is not used. Delivered recommendation link URLs must use https.
• No “powered by” credit, no tracking of visitors, no cookies and no front-end JavaScript. The plugin itself never sends requests to KUROFUNE or any other server (see External services).
• For editors, the admin bar, the post editor and the posts list get “AI rewrite in KUROFUNE” (and “Edit in KUROFUNE” for posts KUROFUNE wrote) links that open the post in KUROFUNE.

KUROFUNE deliveries and cancellation

The plugin shows nothing until KUROFUNE sends the first delivery. An active KUROFUNE plan (including a trial), a WordPress connection, and KUROFUNE LINK being turned on are required for new deliveries.

After cancellation, the last delivered related posts and marked parts remain displayed, but changes are no longer reflected. Archiving the site or deleting its workspace in KUROFUNE also leaves the last delivery displayed. The plugin stays free to use after you cancel, and the last delivery keeps being shown. To stop the display, deactivate the plugin (activating it again shows the last delivery as before).

External services

This plugin is an add-on for KUROFUNE, a service provided by 株式会社KUROFUNE AI (KUROFUNE AI, https://www.kurofune-ai.co.jp/). It does nothing until KUROFUNE starts sending data to it.

What KUROFUNE sends to your site, and when. The plugin itself never contacts KUROFUNE or any other server. Instead, after you connect your site to KUROFUNE (with the WordPress Application Password of an Editor or Administrator that you register in KUROFUNE) and turn on KUROFUNE LINK there, KUROFUNE calls three REST API endpoints that this plugin adds to your site, periodically and when you change something in KUROFUNE:

• POST /wp-json/kurofune-link/v1/sync – KUROFUNE sends: an identifier of your KUROFUNE site, a sequence number, how long that KUROFUNE site reserves this WordPress against another one, pairs of post IDs for related posts and their checksum, the IDs of the posts KUROFUNE wrote, the address of KUROFUNE (used only for the “Edit / AI rewrite in KUROFUNE” links), the current URLs of marked recommendation links, and the HTML of marked CTA blocks and author cards. The plugin stores these values in WordPress options on your site.
• GET /wp-json/kurofune-link/v1/status – KUROFUNE reads: the plugin version, your site’s home URL, the display setting, the detected page-cache plugin, since when a cache purge has been waiting, and whether another KUROFUNE site reserves this WordPress; for its own delivery, also the sequence number, a checksum of the stored post IDs, the remaining reservation time and when delivered items were last rejected.
• GET /wp-json/kurofune-link/v1/usage – KUROFUNE asks which published posts contain one specified recommendation link, CTA block or author card. The response includes up to 200 IDs, titles and URLs of published posts.

All three endpoints require a logged-in user with the edit_others_posts capability (Editor or above). Nothing about your visitors is sent to KUROFUNE.

What your visitors’ browsers load. Delivered recommendation links point to the destinations you registered in KUROFUNE, and delivered CTA blocks and author cards can contain images. An image is loaded by the visitor’s browser from wherever it is hosted: your own media library, KUROFUNE’s image storage, or the address of an image URL you entered in KUROFUNE. As with any image or link in a post, that host receives the visitor’s IP address and browser information; the plugin adds no tracking to these requests.

Links that open KUROFUNE. When an editor clicks “Edit in KUROFUNE” or “AI rewrite in KUROFUNE”, the browser opens KUROFUNE with this site’s host name, the post ID and the chosen action in the address. Nothing is sent until the link is clicked. The links open the KUROFUNE address named in KUROFUNE’s deliveries, and only if it is one of these two (or an address the site’s administrator adds in wp-config.php, see the FAQ):

• https://app.kurofune-ai.co.jp – KUROFUNE, the service that customers use.
• https://kurofune-web-stg-qk2qckvyua-uc.a.run.app – KUROFUNE’s staging environment, used only by KUROFUNE staff and testers to check KUROFUNE before a release. The links open it only on a WordPress site connected to that staging environment.

KUROFUNE’s terms and privacy policy:

• KUROFUNE terms of service: https://www.kurofune-ai.co.jp/terms/
• KUROFUNE privacy policy: https://www.kurofune-ai.co.jp/privacy/

Source code

Everything in this plugin is shipped as human-readable source: the PHP, the stylesheet and the translation source (languages/*.po). There is no build step other than compiling the .po file into the bundled .mo file with gettext’s msgfmt. Development-only files (unit tests, coding-standards configuration) are left out of the zip.