AI FAQ Chat — AlexHost case study

Not a drop-in WordPress plugin. This is the custom FAQ chatbot built for alexhost.com: it indexes the hosting catalog (FAQ, tariffs, coupons, SSL, blog posts, pages) and answers visitors from that knowledge — not from a generic “FAQ CPT only” template.

Live on the production site. Credentials never live in git (SECURITY.md).

What it does

A visitor asks about VPS, a coupon, or an SSL cert. The widget (POST /wp-json/ai-faq-chat/v1/message) answers from indexed site content:

1. Primary — Node RAG (knowledge_chunks): WP save_post queues a reindex; the chat backend embeds the page.
2. Fallback — PHP embeddings in wp_aifaq_embeddings + WordPress search, if Node is not configured.

The plugin is wired to this theme’s post types and ACF fields (prices, promo codes, CPU/RAM/storage). It will not make sense on an unrelated WP site.

Indexed content

Allowlists:

• Node reindex: includes/class-node-reindex-hook.php
• PHP index + config: includes/class-embeddings.php, config/site-config.php content_types

Tariffs / coupons / SSL are theme CPTs. The plugin only indexes them; it does not register those types.

Indexing logic

Editor publishes a post
        │
        ▼
  type in allowlist? ──no──► ignore
        │ yes, status=publish
        ▼
  WP-Cron (~5s)  ──►  Node POST /internal/reindex
                      { url, content_hash, post_id, post_type }
                      Node fetches the URL and stores chunks

  PHP fallback (admin bulk index / embeddings):
        title + excerpt + first 5k of body
        + ACF: price, links, promo-coupon, CPU, RAM, storage, features
        → OpenAI embedding → wp_aifaq_embeddings

• Autosaves, revisions, and password-protected posts are skipped.
• Node gets a hash + permalink, not the full body; the chat server crawls the URL (idempotent via content_hash / X-Event-Id).
• Keyword fallback (class-content-search.php) queries faq-post, services, coupon, certificate (not generic post/page).

Visitor path: widget → /message → Node /internal/ai/chat when a reindex token is set; otherwise PHP semantic/keyword search over the indexed types.

Secrets

API keys, reindex Bearer, and live-chat secret are WordPress Settings / wp-config.php only. This repo has empty defaults and 127.0.0.1 placeholders in the admin UI. See SECURITY.md.

Layout

Tests

npm test

License

MIT — published as a portfolio case, not a product to install on third-party sites.

Changelog: CHANGELOG.md.