RefChat is not a general-purpose chatbot plugged into your PDFs. It's a research tool built around one requirement: every answer must be traceable back to your documents. Robustness isn't a marketing option here, it's the backbone of the product.
1. Source, don't invent
The number-one risk of an AI assistant is hallucination: producing a credible claim that nothing supports. RefChat is built to avoid it. Every answer relies on passages actually present in your documents, and cites its sources. When the corpus doesn't contain what's needed to answer, RefChat says so explicitly rather than filling the gap. For a researcher, a lawyer or an expert, that "I don't have the source" is a feature, not a flaw.
2. Multi-stage hybrid search
Finding the right passage among hundreds of articles is a hard problem. RefChat combines several complementary approaches rather than relying on a single one:
Semantic
A multilingual model understands the meaning of your question, beyond the exact words — a question in English finds an answer in a French article.
Lexical
A keyword search captures the precise technical terms, acronyms and proper nouns that semantics alone might dilute.
Reranking
A second pass reorders the candidate passages from most to least relevant, so only the best material is presented to the model.
This combination is markedly more accurate than a basic single-stage "RAG". And because structured documents (sections, titles) are respected, the cited passages stay coherent units of meaning, not fragments cut at random.
3. Clean text, even from difficult PDFs
A search engine is only as good as the text it's given. RefChat cleanly extracts the content of your PDFs — including OCR for scanned documents — and handles multilingual content end to end. Less noise in means fewer errors out.
4. A verified chain, from install to update
Robustness doesn't stop at answer quality: it also covers the integrity of the software itself. RefChat verifies the integrity of its components — the analysis building blocks and the updates are checked before use, to prevent a tampered file from running without your knowledge. Any secrets (access keys) are protected on your machine. It's the kind of security hygiene you expect from professional software, and we apply it.
5. Your data stays with you
In local mode, your articles, patents and sensitive reports never leave your machine: no third-party service, no data sent out, no model training on your content. If you prefer performance, cloud mode runs on European infrastructure (OVHcloud, France), within a GDPR-compliant framework. Either way, you decide where your data lives.
In short
RefChat is robust because it's designed to be verifiable at every step: sourced rather than invented answers, multi-stage search rather than a shortcut, a software chain whose integrity is checked, and confidentiality as the default setting. We deliberately keep the detail of our methods to ourselves — but the result is built to withstand scrutiny.