Champlin AI Internal Linker self-updates

Semantic internal-link suggestions for WordPress, powered by OpenAI embeddings. Free and GPL-licensed, with no per-seat fees.

What it does

• Indexes your posts into vector embeddings (default: text-embedding-3-small, 1536d, ~6KB/post)
• Surfaces semantically relevant internal-link suggestions inside the block editor sidebar
• Auto-picks an anchor phrase from the sentence in your draft closest to the target post
• One click to insert; acceptances are logged so the same target stops reappearing

Architecture

• PHP 8.1+ with strict types, PSR-4 (Champlin\InternalLinker\), Composer autoloaded
• WordPress 6.4+ Gutenberg-first; sidebar is React via @wordpress/scripts
• MySQL — two custom tables (cil_embeddings, cil_suggestion_log); embeddings stored as packed float32 BLOBs
• Action Scheduler for background indexing
• Tailwind for admin pages (built, not CDN)
• No vector DB; cosine ranking happens in PHP against batched embeddings

champlin-ai-internal-linker/
├── champlin-ai-internal-linker.php   # Bootstrap, plugin header
├── composer.json
├── package.json
├── tailwind.config.js
├── phpcs.xml
├── phpunit.xml.dist
├── uninstall.php
├── readme.txt                         # WP.org-format readme
├── src/
│   ├── Plugin.php                     # Container + hook registration (single place)
│   ├── Embeddings/                    # ProviderInterface, OpenAIProvider, ProviderFactory
│   ├── Storage/                       # VectorStore, SuggestionLog, Schema
│   ├── Similarity/                    # CosineCalculator
│   ├── Engine/                        # SuggestionEngine, AnchorExtractor
│   ├── Indexing/                      # IndexQueue, BulkIndexer, ContentNormalizer
│   ├── REST/                          # SuggestionsController, IndexController, BaseController
│   └── Admin/                         # SettingsPage, IndexerPage, EditorAssets
├── includes/views/                    # Server-rendered admin views (settings, indexer)
├── assets/
│   ├── editor/index.js                # Gutenberg sidebar (React)
│   ├── admin/                         # Tailwind source + indexer.js
│   └── dist/                          # Built output (gitignored)
├── languages/                         # .pot files
└── tests/                             # PHPUnit + Brain Monkey

Development

composer install
npm install

# Watch the admin Tailwind CSS:
npm run watch:admin

# Build editor + admin bundles:
npm run build

# Run unit tests:
composer test

# Lint:
composer lint

Local dev install

Symlink into a WordPress dev install:

ln -s "$(pwd)" /path/to/wordpress/wp-content/plugins/champlin-ai-internal-linker

Activate via wp-admin → Plugins, then enter an OpenAI key in AI Linker → Settings.

Distribution

• GitHub: tagged releases with the full source tree; users get auto-updates via yahnis-elsts/plugin-update-checker.
• WordPress.org: ./scripts/build-wp-org.sh produces a stripped variant (PUC removed, dotfiles excluded) ready for SVN check-in.

Performance targets

• Single-post index: <2s end-to-end (dominated by API latency)
• /cil/v1/suggestions/{post_id} p95 on a 1K-post site: <300ms
• Full re-index of 1K posts: <15 min at default Action Scheduler concurrency

Hard rules (Plugin Check + WP.org review)

• All file ops via WP_Filesystem (none currently needed — but if added, no direct mkdir/unlink)
• Every $_POST/$_GET/$_SERVER access goes through wp_unslash() BEFORE sanitization
• No short echo tags (<?= … ?>) — use <?php echo esc_html(...); ?>
• Build script excludes .git, .github, .gitignore, .DS_Store, .editorconfig
• Every REST route checks capability + nonce
• All $wpdb calls use prepare() — no string interpolation

License

GPLv2 or later © Champlin Enterprises. See LICENSE.