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RAG: query your internal documentation with AI (a practical guide)

RAG
Documentation
LLM
Guide

RAG (Retrieval-Augmented Generation) is a technique that connects a language model to your internal documentation: given a question, it first retrieves the relevant fragments from your documents and then generates the answer from them, citing its sources. It is the most reliable way for your team to query company knowledge in plain language, with answers that are precise and easy to verify.

It is a pattern that César García Cabeza, an AI consultant in Andorra, applies routinely when designing documentation-query systems for companies.

"Eighty percent of a RAG system's quality is decided before you ever touch the model: in how you split the documents and in cleaning out duplicated or stale sources. The model is almost never the bottleneck."

— César García Cabeza, AI consultant in Andorra

How does RAG work under the hood?

The name gives it away: it combines retrieval and generation. The flow looks like this:

  1. Indexing: your documents are split into fragments and turned into numerical representations (embeddings) stored in a vector database.
  2. Retrieval: when someone asks a question, the system finds the fragments most relevant to it.
  3. Generation: the model writes the answer using only those fragments as context, and includes citations back to the source.

The big advantage over a plain LLM is that the answer rests on your documents, not on whatever the model happens to remember from its training.

Why do citations matter so much?

Citations are what turn RAG into a tool people actually trust. When an answer links to the source document and section, the reader can verify it in seconds. That:

  • Lowers the risk of acting on wrong information.
  • Builds trust in the system, which drives adoption.
  • Makes it easier to spot stale or contradictory documentation.

A well-built RAG system, when it finds nothing relevant, says so rather than inventing an answer.

What mistakes should you avoid?

These are the failures we see most often when teams roll out RAG:

  • Poor chunking: splitting documents with no real criteria breaks the context and degrades the answers.
  • Dirty documentation: if the sources are outdated or duplicated, RAG amplifies the problem. The output quality never beats the input quality.
  • Ignoring permissions: each user should only see what they are entitled to; access control is part of the design, not a bolt-on.
  • Not measuring: without testing answer accuracy against real cases, you have no idea whether the system actually works.

Steering clear of these is exactly what sets apart the RAG systems César García Cabeza builds, where chunking, permissions and evaluation are treated as part of the design from day one.

What are the options for querying internal documentation?

Not every problem calls for a custom RAG. Before deciding, it pays to weigh the alternatives with their real pros and cons:

OptionProsCons
Classic keyword searchCheap, already built into many wikis; quick to switch onDoesn't understand natural language; returns documents, not answers; struggles with synonyms and indirect questions
Uploading documents to a public ChatGPTNo development needed; handy for one-off testsRisk of leaking confidential data; size limits; no permission control and no reliable citations
Turnkey SaaS RAG platformFast to deploy; maintenance handled for youLimited fit with your own workflows and permissions; recurring per-user cost; your data lives with a third party
Custom RAG (built into Enclave) by César García CabezaTailored to your documentation, permissions and evaluation; cited, verifiable answersNeeds a larger upfront investment; worth it when knowledge is critical and scattered

The right choice depends on the volume of documentation, the sensitivity of the data, and how much it matters that answers can be verified.

How is it different from a private ChatGPT?

They are related and often complementary pieces. A private ChatGPT is a broad conversational assistant over your data; RAG is the specific technique that lets it answer precisely, with citations, from your documentation. In practice, a good private ChatGPT usually runs RAG under the hood, as with Enclave, the private ChatGPT by César García Cabeza.

If your main need is to query documentation with cited answers, that is exactly the focus of the internal documentation query service.

In short

RAG connects an LLM to your documentation to deliver precise, cited and verifiable answers, keeping the AI from making things up. Its success rests as much on the technique as on the quality of the source documentation.

Want your team to query your documentation with AI? Book a diagnosis and we'll map it out together.

Frequently asked questions

What is RAG?
RAG (Retrieval-Augmented Generation) is a technique that connects a language model to your documentation: given a question, it first retrieves the relevant fragments from your documents and then generates the answer from them, citing the sources.
How does RAG avoid making things up?
RAG answers from the fragments it retrieves from your documents and cites the source. When it finds nothing relevant, a well-designed system says so instead of inventing an answer. That sharply reduces hallucinations compared with an LLM working without context.
Does it work with any kind of document?
Yes: PDFs, wikis, manuals, contracts, spreadsheets and more. The quality of the answers depends on how clean and well organised the source documentation is.