Course · Advanced Trending

Build a RAG Knowledge Base in WordPress: Embeddings, Vector Search & Semantic Retrieval

A complete, production-oriented retrieval-augmented generation pipeline for WordPress, chunking real content, generating and storing embeddings, running semantic search in PHP, and grounding an AI assistant's answers so it stops guessing and starts citing your actual site.

9 lessons
Start course →

Course 5, LLM Integration in WordPress With the PHP AI Client SDK, introduced embeddings in a single lesson: what they are, one real method call, one small cosine similarity function. That was enough to understand the concept. It is nowhere near enough to ship an AI assistant you’d trust in front of real users, and that gap is what this course closes.

This course goes deep on the part of the stack that decides whether an AI assistant built on your WordPress site tells the truth or confidently makes something up. Anything built in WordPress AI Foundations or the assistant, agent, and automation courses that follow it can call an LLM. Only a real retrieval pipeline, chunked content, stored embeddings, a working similarity search, and a prompt that hands the model actual retrieved passages, can make that LLM answer questions about your specific site instead of its training data. That’s retrieval- augmented generation, RAG, and it is arguably the single most important course in this whole track for anyone who cares about their assistant being accurate rather than merely fluent.

You’ll build the full pipeline end to end: turning WordPress posts into embeddings with the real, current PHP AI Client SDK method, chunking long content sensibly instead of naively, storing vectors in a custom database table with dbDelta(), writing a brute-force cosine similarity search in plain PHP, and constructing a grounded prompt that feeds retrieved chunks to wp_ai_client_prompt()->generate_text() so the model answers from your content instead of improvising. The course closes with the sync problem every real deployment hits: keeping embeddings current as content changes.

Nothing here is invented. Where WordPress genuinely has no official answer, most notably vector storage, this course says so plainly and shows you the real, honest options instead of a made-up “official” plugin. If you’re building the conversational assistant from Course 3, the editorial tools in Course 6, or the autonomous agents later in the track, treat this course as the foundation those projects need to be trustworthy, not just capable.