crossref-mcp-server

<div align="center"> <h1>@cyanheads/crossref-mcp-server</h1> <p><b>Resolve DOIs, search ~155M scholarly works, fetch references, and look up publishers via the Crossref REST API. STDIO or Streamable HTTP.</b> <div>7 Tools</div> </p> </div> <div align="center">

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Tools

Seven tools for working with Crossref data — DOI resolution, full-text search across all scholarly works, outgoing reference lists, and journal, funder, and publisher lookup:

| Tool | Description | |:-----|:------------| | crossref_get_work | Resolve a DOI to its full Crossref metadata record: title, authors, affiliations, abstract (when deposited), journal, publication date, type, license, full-text links, funder acknowledgements, and outgoing reference count. The author list pages by offset/limit. | | crossref_search_works | Search the Crossref works index by free text and/or structured filters. Supports sort, field selection, a per-work author cap, and cursor-based deep paging. | | crossref_get_references | Return the outgoing reference list for a DOI — the works cited by this paper, with deposited citation strings and resolved DOIs where available | | crossref_search_journals | Find Crossref journal records by ISSN or title query; optionally retrieve a page of the journal's most recent works by publication date. Both lists page by offset. | | crossref_search_funders | Find funders registered in the Crossref Funder Registry by name, bare registry ID, or funder DOI; optionally retrieve a page of funded works. Both lists page by offset. | | crossref_get_member | Resolve a Crossref member ID to its publisher record — name, owned DOI prefixes, DOI counts, per-work-type breakdown, and per-category metadata deposit coverage | | crossref_get_prefix | Resolve a DOI prefix (e.g. 10.1038) to its owning publisher — name and member ID, chaining into crossref_get_member |

crossref_get_work

Resolve a DOI to its canonical Crossref record.

• DOI validated against 10.NNNN/suffix regex before the upstream call
• Returns title, authors with affiliations, abstract (when deposited), container/journal, publication date, work type, ISSN, license URLs, full-text link URLs, and funder acknowledgements
• The author list is paged with offset and limit (default 25, max 500). authorCount is the full deposited total; when authors remain, the response carries a nextOffset to pass back as offset. Ordinary records fit in a single page — large-collaboration papers deposit thousands of authors, enough to fill a client's context from one record. Only the author list is paged; every other field comes back in full on every page.
• A funder or an affiliation the publisher asserted through the ROR registry rather than by name carries that identifier as ror, and no name. The entry still names an organization instead of coming back as an award number with nothing attached to it.
• A date component Crossref records as unknown — it deposits null in place of the number — is omitted rather than reported, so a record with no registered year comes back with no publication date.
• The publication date is the first of published, published-print, published-online, and issued that names one. The three search tools read the same order without issued, which is this tool's alone. A source deposited holding only unknown components names nothing and is passed over; one naming a coarser date than the source behind it still answers, since the four are different facts rather than one fact at four precisions.
• Outgoing references are reported as a count; the entries themselves come from crossref_get_references
• Incoming citation count (is-referenced-by-count) is included; citing works are not — Crossref does not expose that data. Use OpenAlex for citation graphs.

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crossref_search_works

Search across ~155M Crossref-registered works.

• Free-text query plus a structured filter object using Crossref's hyphen-separated key syntax: from-pub-date, until-pub-date, type, funder, issn, member, has-abstract, has-references, has-full-text, directory (use DOAJ to restrict to open-access content)
• Field-specific query parameters scope matching beyond the generic query: queryTitle, queryAuthor, queryContainerTitle (journal/book name), and queryBibliographic (whole-citation match to resolve a known reference to its DOI) — all combine with each other and with query
• Sort by relevance, is-referenced-by-count, published, deposited, or score
• fields parameter narrows response payload — useful for large result sets. Names are case-sensitive; DOI is always returned whether or not it is listed, so every result stays resolvable by crossref_get_work.
• Each work returns at most authorLimit authors (default 25, max 500), with authorCount reporting that work's full deposited total. A single page of large-collaboration papers can carry tens of thousands of author entries; pass a cut work's DOI to crossref_get_work to page its whole author list, or raise authorLimit to widen the cap here.
• Offset paging up to ~10K results; deep paging requires cursor=* on the first call, then pass the returned nextCursor token. Cursor and offset cannot be combined.
• A cursor walk ends on the page that omits nextCursor. Crossref keeps minting a token past the end of a list, so the token is withheld on an empty page rather than relayed — the rule the works_cursor walks below follow too. Here that page also carries a notice saying the walk is complete, because works is this tool's whole payload and an empty page nothing is said about renders as blank text.

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crossref_get_references

Fetch the outgoing reference list for a DOI.

• Each reference includes its deposited citation string and, where Crossref has resolved it, a DOI for follow-up lookup
• Citation strings come back with markup removed — inline emphasis (<i>, <em>, <small>, <span>), scripts (<sub>, <sup>, <inf>), block boundaries (<p>, <br>, <refersplit />), MathML and TeX formula wrappers, and a whole JATS <mixed-citation> deposited into a free-text field. A bracket comes out only when it is a well-formed tag whose element name is on a closed list, so an angle-bracket span that is not one — a cited URL, a Miller index, a DOI fragment, a bracketed phrase — is returned exactly as deposited. A link (<a>, <ext-link>, <uri>) is decided against its own text: its tags come out where the text already carries what the href holds, and stay where the href addresses something the text does not name.
• Paged with offset and limit (default 100, max 500). referenceCount is the full deposited total; when more remain, the response carries a nextOffset to pass back as offset. Most works fit in a single page — bibliography records can carry tens of thousands of references.
• Coverage varies by publisher — pre-2000 literature and non-participating publishers may have no reference list
• Single-hop only; agents that need N-hop traversal chain calls explicitly

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crossref_search_journals

Find journal records by ISSN or title.

• include_works: true also returns a page of the journal's most recent works by publication date
• Returns journal title, publisher, ISSN-L, subject areas, and total DOI count
• Title-query results page with offset; journalsTotal reports the full match count and nextOffset carries the input for the following page. The journal works list pages separately with works_offset and nextWorksOffset.
• The two lists have different ceilings: title search allows offset + rows up to 100,000, the works list only 10,000. A page that stops at either ceiling carries a notice saying so — a missing continuation offset would otherwise read as the end of the list.
• The journal works list also pages by cursor, which has no ceiling: pass works_cursor="*" and chain the nextWorksCursor token from each response to read the whole list. A cursor walk starts at the newest work and cannot resume from an offset, and the two cannot be combined — works_cursor with a nonzero works_offset returns works_cursor_offset_conflict. Each token runs about 1500 characters on both result surfaces, a cost per page rather than per record, so a long walk is cheaper at a high rows.
• include_works needs an unambiguous journal. A title query matching more than one — measured by the upstream match count, not by how many fit on the requested page — returns ambiguous_journal, naming the page's candidates and their ISSNs in the message and in candidates on the error data, alongside the full match count. Pass one back as issn, or narrow the query when the journal you want is not among them.
• The works list is addressable by ISSN alone, so a matched journal with none registered has no works list to request. include_works is then skipped and the response carries a notice saying so — an absent recentWorks would otherwise read as a journal with no works, and totalDois is the journal's own DOI count rather than an answer about the lookup. There is no alternative identifier to retry with; use crossref_search_works with queryContainerTitle instead.

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crossref_search_funders

Find funders in the Crossref Funder Registry.

• Accepts a name query, a bare registry ID (100000001), or a full funder DOI (10.13039/100000001, optionally behind a doi: or https://doi.org/ prefix)
• include_works: true also returns a page of works funded by the matched funder
• Returns funder name, registry ID, country, and alternate names
• Name-query results page with offset; fundersTotal reports the full match count and nextOffset carries the input for the following page. The funded works list pages separately with works_offset and nextWorksOffset.
• The two lists have different ceilings: name search allows offset + rows up to 100,000, the works list only 10,000. A page that stops at either ceiling carries a notice saying so — a missing continuation offs