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Citation RAG

Citation-grounded RAG

Answers you can verify, line by line.

A retrieval-augmented answer engine where every claim is grounded in a specific source passage — with inline, checkable citations and an abstain path when the corpus doesn't support an answer. Built for high-stakes text, where a confident wrong answer is worse than no answer.

The demo corpus is the U.S. founding documents — the Constitution, the Bill of Rights, and the Federalist Papers (public domain) — so every answer is externally checkable.

The specimen · one cited claimverbatim source

The First Amendment bars Congress from establishing a religion or prohibiting the free exercise thereof.1

[1]U.S. Constitution — Amendment I

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble…

Every span links to a verbatim source — or the engine abstains. Native citations, not made-up [1]s.
1.00
faithfulness · Claude judge
3/3
abstain · out-of-corpus
0.909
recall@5 · hybrid RRF
0.809
MRR · hybrid RRF

How it works

Two readings, fused — then grounded, or withheld.

Retrieval finds the passages; generation is constrained to cite them. The whole path is scored by an eval harness that gates CI on retrieval recall and answer faithfulness.

01Hybrid retrieval

BM25 lexical and dense embeddings, fused with Reciprocal Rank Fusion — exact terms, names, and §-numbers from one; paraphrase and concept matches from the other. Neither half alone is enough.

02Native, verifiable citations

Sources go to Claude as document blocks with citations enabled, so every cited span is a real substring of a real passage — not a model-invented [1]. Open any marker to read it in context.

03Abstains, doesn't guess

When retrieval surfaces no supporting evidence, the engine declines instead of fabricating. An out-of-corpus question is met with silence, not confidence — measured at 3/3 abstain accuracy.

Citation-Grounded RAG — query & answer flowArchitecture
Question
streamed end-to-end

Hybrid retrieval

BM25 lexical
exact terms · names · §-numbers
Dense embeddings
paraphrase · concepts
Reciprocal Rank Fusion
→ top-k (+ optional rerank)
Claude · document blocks, citations enabled
native cited spans, not made-up [1]s
Streamed cited answer
[n] chips open the source
or Abstain
no supported evidence
Lexical and dense retrieval are fused with Reciprocal Rank Fusion; sources go to Claude as document blocks with citations enabled, so every answer span links to a verifiable source — or the engine abstains.

Ask it something checkable.

Query the founding documents and watch every claim attach to the exact passage that supports it — or watch it decline when the sources don't.

Ask the corpus