Gated RAG with an ai_decide layer: abstain when evidence is missing instead of hallucinating

Limp-Park7849 · reddit · 2026-10-15

The author contrasts traditional RAG with a gated pipeline built around an aidecide decision layer:

Traditional RAG: question → top-k similarity retrieval → the LLM always writes an answer, even when the passages don't contain it, often with real-looking citations.
Gated RAG: three checkpoints — (G0) is the question in scope? If not, reply out-of-scope with no retrieval or generation; (G1) do the retrieved hybrid BM25+vector passages fully answer it? If not (P < τ), clarify, abstain, or escalate with 0 generation tokens; (G2) is every claim in the draft supported? If not, withhold the draft and abstain.

Retrieval is hybrid BM25 + vector (top 5), bilingual EN/FR, and the LLM may only answer from cited passages. The core idea: teach the system not to answer when the evidence isn't there, suppressing hallucination at the source.

Original post →

Gated RAG with an ai_decide layer: abstain when evidence is missing instead of hallucinating

More from coding & agent