naulon

Score how relevant each candidate is to the topic, from its free teaser alone — a 0..1 relevance plus a one-line rationale. Pass the candidates you got from naulon_discover (or a curated subset), and pass them back WHOLE — `matchedInBody` / `matchedSemantic` tell the scorer WHY the search returned each one, and dropping them makes a body-matched source with a terse teaser look identical to a near-miss with a keyword-ish one. FREE: it reads the teaser and those flags, never paid content, and it fetches and pays for nothing. Use it to decide what is worth quoting.

FREE citation and retraction check. For up to 25 references (a DOI, PMID, PMCID, arXiv id, or the reference as written), say whether each work exists and whether it was retracted, withdrawn, corrected or put under an expression of concern. Use it before you cite. Facts from Crossref and Retraction Watch; no judgement of the research. For a retracted or withdrawn citation, up to three reviews and trials that cite it are suggested; for an unfound one, up to three papers on its subject; each with its licence.

Browse a TOPIC: list candidate articles by title and teaser, with no verdict on whether any of them answers a question. Returns FREE public teasers only — slug, title, and summary — with no content and no payment. Call this first to see what is available before appraising or quoting. A candidate may carry WHY it matched: `matchedInBody` means your terms are inside the paid text but NOT in the title or teaser (strong — the teaser just does not show it), `matchedSemantic` means only that it is near your query in meaning and your terms are absent (weak: judge the teaser, and set aside one that is off-topic). NEITHER flag set means one of two opposite things, so read it against the rest of the response: if any OTHER candidate here carries a flag, this source searches, and no flag is the STRONGEST result of all — your terms matched the title or teaser, which is why no body-only or semantic explanation was needed. If NO candidate in the response carries a flag, the source does not search (a plain RSS feed), and the absence says nothing at all — judge every candidate on its teaser. Discovery returns the best available matches, never a promise that any of them answers your question.

FREE. Get the record of one source you already have the address of: a publisher page by its URL, or a paper by DOI, PMID, PMCID or arXiv id. For a page it returns the title, site, summary and its read and citation prices. For a paper it returns the title, authors, venue, year, retraction and correction notices, licence, abstract where it may be shown, and where a free copy is. It searches nothing: to find sources by topic use naulon_discover or naulon_search.

Probe the real x402 toll for a source WITHOUT paying — the free 402 price check. Returns the author price, the buyer's true total (when the publisher adds extra settlement legs such as an operator fee, the total is higher than the author price), and the settlement terms. gated:false means one thing only — the origin answered 2xx, so it is a genuinely free read you may just fetch. Anything else returns refused:true with the reason in note: a refusal to reach the url (off-gate identity, or operator policy such as a kill-switch or deny-list), a 404, an unreachable origin, or a malformed 402. A refused url is NEITHER payable nor free — do not fetch it and do not report it as free; retry or fix the url.

FREE preview, RESEARCH PAPERS only. For a question, lists the open CC0, CC BY, CC BY-SA or public-domain papers that could answer it and the price of each mode (answer, retrieve). This tool never pays and never runs the answer. Prices only: nothing on this server buys. How buying works: https://naulon.app/docs/for-buyers

FREE. Ask a QUESTION: search every naulon publisher's articles and get each match priced, with its public summary, `url`, and a verdict on whether it answers the question and what reading it would add. For a plain list of a topic's articles with no verdict, use naulon_discover. Prices only: nothing on this server buys. How buying works: https://naulon.app/docs/for-buyers

FREE. Find which naulon publisher pages a passage was copied from, word for word. Returns each page's title, url, and whether it holds most of the passage or part of it, plus how many Citation Licenses the page has sold where its publisher shows that. It detects verbatim reuse only, not paraphrase or training. Send 40 words to 5000 characters.