What is it?
Basic RAG always searches once. Agentic RAG lets the AI act like a researcher: reword the question, try a different source, notice weak results and try again before answering.
Also known as: agentic RAG, self-RAG, corrective RAG, CRAG, adaptive RAG, iterative retrieval, multi-hop RAG, query decomposition.
Technical definition
Patterns: query rewriting/decomposition, routing among indexes or tools, relevance grading with retry (Corrective RAG, Yan et al., 2024), self-reflective retrieval where the model decides when to retrieve (Self-RAG, Asai et al., 2023), and iterative multi-hop retrieval. It combines What is RAG (Retrieval-Augmented Generation)? with The ReAct Pattern (Reason + Act). Extra LLM calls add latency and cost, and a mis-judging grader can discard good evidence.
Entity type: technique · Freshness class: evolving.
When should I use it?
Use when single-pass retrieval fails on multi-hop or ambiguous questions.
Implementation patterns
- Rewrite → retrieve → grade → (retry | answer).
- Router selects among vector, keyword and web search.
- Decompose into sub-questions; answer; synthesise.
- Hard cap on retrieval iterations.
Technologies and frameworks
Commonly associated: LangGraph, LlamaIndex agents, search tools, rerankers. Names are examples of what exists, not recommendations, and projects change quickly.
Practical guide
- Measure plain-RAG failures first.
- Add the smallest loop that fixes them.
- Limit iterations.
- Evaluate end-to-end and retrieval separately.
Common failure modes
- Loops that never stop.
- Grader errors discarding useful passages.
- Latency and cost multiplication.
- Injected instructions in retrieved text (What is Prompt Injection?).
Troubleshooting
- Slow answers — Cap iterations, parallelise sub-queries, use a small grader model.
- Answers still ungrounded — Require citations and verify them against retrieved text.
Contrasted with
- What is RAG (Retrieval-Augmented Generation)? — Standard RAG is one fixed retrieval pass; agentic RAG loops and adapts.
- The ReAct Pattern (Reason + Act) — ReAct is the general loop; agentic RAG applies it to retrieval.
Questions this page answers
- What is agentic RAG?
- What is self-RAG?
- When should RAG retrieve more than once?
- How do I make RAG handle multi-hop questions?
Typical goals: handle complex multi-part questions; add self-checking to RAG.
Sources and verification
Status: not independently verified. This entry was authored on 2026-10-06 from general technical knowledge, without live checking of the sources below. Treat every source as a lead to confirm (identifier, title, authorship, current version) before publication or citation.
Freshness class: evolving — Established techniques whose best practice shifts as research and tooling move. Re-review every 6 months.
Canonical sources (unverified leads):
- Asai et al., Self-RAG (2023) — arXiv:2310.11511
- Yan et al., Corrective Retrieval Augmented Generation (2024) — arXiv:2401.15884