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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Public Hosted Server: https://crossref.caseyjhand.com/mcp

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Overview

Scholarly metadata from the Crossref REST API. Resolve DOIs to full metadata records, search across ~155 million scholarly works by free text or structured filters, fetch outgoing reference lists, and look up journals, funders, and publishers. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.

Tools

| Tool | Description | |:---|:---| | crossref_get_work | Resolve a DOI to its full Crossref metadata record: title, authors, editors, affiliations, abstract, journal with volume/issue/pages, ISSNs and ISBNs, publication date, license, full-text links, funder acknowledgements, post-publication updates, and related identifiers | | crossref_search_works | Search the Crossref works index by free text and/or structured filters, with field-scoped query parameters, sort, field selection, and offset or cursor-based paging | | crossref_get_references | Return the outgoing reference list for a DOI — the works cited by this paper, with 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 | | crossref_search_funders | Find funders in the Crossref Funder Registry by name, registry ID, or funder DOI; optionally retrieve a page of funded works | | crossref_get_member | Resolve a Crossref member ID to its publisher record — name, owned DOI prefixes, DOI counts, and per-category metadata deposit coverage | | crossref_get_prefix | Resolve a DOI prefix (e.g. 10.1038) to its owning publisher, chaining into crossref_get_member |

Capability reference

crossref_get_work _tool

• DOI validated against the 10.NNNN/suffix regex before the upstream call, accepted either bare or wrapped in its resolver (https://doi.org/…, https://dx.doi.org/…, doi:…) and unwrapped before the lookup
• Returns title, authors with affiliations, abstract (when deposited), container/journal, publication date, work type, ISSN, license URLs, full-text link URLs, and funder acknowledgements
• Citation locators volume, issue, page, and articleNumber under the same names and on the same rendered line as crossref_search_works, plus isbn — each as deposited, omitted when absent
• editors in the author entry shape, returned whole and never counted in authorCount
• Author list paged by offset/limit (default 25, max 500); authorCount reports the full deposited total and a nextOffset continues when authors remain — every other field is returned in full on every page
• updatedBy lists the corrections, retractions, expressions of concern, and new versions Crossref records against the work — notice DOI, type, source (publisher or retraction-watch, with its record ID), and date, entry for entry — and updateTo the works this record is a notice for; when updatedBy is present, notice names each update type with its sources. An absent updatedBy does not mean the work was never updated
• relations groups related identifiers (preprint ↔ published version, versions, reviews, supplements) by relation type, identifier type, and asserting party, returned whole; only Crossref-registered DOIs among them resolve through this tool
• A funder or affiliation asserted only through the ROR registry (no name deposited) carries ror in place of name, never as a blank entry
• Publication date is the first of published, published-print, published-online, and issued (this tool only) that names a value; a date component Crossref records as unknown is omitted, along with everything less precise below it
• Outgoing references are reported as a count (referencesCount) — entries come from crossref_get_references; incoming citation count (isReferencedByCount) is included, but citing works are not exposed by Crossref — use OpenAlex for citation graphs

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crossref_search_works _tool

• Free-text query plus a structured filter object using Crossref's hyphenated keys (from-pub-date, type, funder, issn, has-abstract, license.url, etc.)
• Field-scoped parameters queryTitle, queryAuthor, queryContainerTitle, and queryBibliographic combine with query and with each other
• Sort by relevance, score, is-referenced-by-count, published, deposited, or other listed fields — the publication-date sorts page by offset only, since Crossref refuses them with a cursor
• fields narrows the payload to any of the 17 select names the summary projects — including the citation locators volume, issue, page, article-number, and ISSN — and refuses any other name; DOI is always returned, and crossref_get_work carries the rest of the record
• A blank or whitespace-only query term or filter value, and an empty sort or order, is read as omitted; when that leaves nothing to search by, the notice says the page is an unfiltered listing
• authorLimit caps authors per work (default 25, max 500); authorCount reports the full deposited total — chain a cut work's DOI into crossref_get_work for the rest
• Offset paging is capped at ~10K; cursor="*" starts deep paging via chained nextCursor tokens — cursor and offset cannot be combined
• A cursor walk ends on the page that omits nextCursor — an empty page never carries one; every empty page's notice names which of the three causes applies

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crossref_get_references _tool

• Takes the citing work's DOI bare or resolver-wrapped, the same forms crossref_get_work accepts
• Each reference carries its deposited citation string and, when Crossref has resolved it, a DOI for crossref_get_work
• Citation strings have formatting markup stripped and character references decoded; a bracketed span that isn't a recognized tag (a cited URL, a Miller index, a DOI fragment) is left exactly as deposited
• Paged by offset/limit (default 100, max 500); referenceCount is the full deposited total and nextOffset continues when more remain
• Coverage varies by publisher — pre-2000 works and non-participating publishers often have no indexed references
• Single-hop only; incoming citations are not available through Crossref — use OpenAlex for citation graphs

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crossref_search_journals _tool

• include_works: true also returns a page of the journal's most recent works — newest published first by works_offset, newest registered first on a works_cursor walk; requires an unambiguous journal — a title query matching more than one returns ambiguous_journal, naming candidates and ISSNs
• Returns journal title, publisher, ISSN-L, subject areas, and total DOI count
• Title-query results page by offset (ceiling offset + rows ≤ 100,000); the works list pages separately by works_offset (ceiling ≤ 10,000) — a page that stalls at either ceiling, or an offset past the end of either list, carries a notice naming it
• works_cursor="*" pages the works list with no ceiling via chained nextWorksCursor tokens; a cursor walk runs by Crossref registration date, newest first (Crossref does not walk a publication-date sort by cursor), and cannot combine with works_offset > 0 (works_cursor_offset_conflict)
• A matched journal with no ISSN registered has no addressable works list — include_works is skipped with a notice rather than returning an empty list

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crossref_search_funders _tool

• Accepts a name query, a bare registry ID (100000001), or a full funder DOI (10.13039/100000001, optionally behind a doi:/https://doi.org/ prefix)
• include_works: true also returns a page of funded works; requires an unambiguous funder — a name query matching more than one returns ambiguous_funder, naming candidates and registry IDs
• Returns funder name, registry ID, country, and alternate names
• Name-query results page by offset (ceiling ≤ 100,000); the funded-works list pages separately by works_offset (ceiling ≤ 10,000) or, with no ceiling, works_cursor="*" chaining nextWorksCursor — offset pages run newest published first, a cursor walk newest registered first, and the two cannot combine (works_offset > 0); an offset past the end of either list carries a notice naming it
• The funded-works list also counts works funded by the funder's registry descendants, which a crossref_search_works filter on {"funder": "10.13039/<id>"} does not
• A deprecated registry entry answers to its successor's name while counting only its own works — the response's notice names the superseding ID via replacedBy; the replacement is never followed automatically

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crossref_get_member _tool

• Members are the organizations that register DOIs — this answers "what does this publisher publish, and how completely do they deposit metadata?"
• Returns primary name, alternate imprint names, owned DOI prefixes, DOI counts (total/current/backfile), a per-work-type breakdown, and per-category metadata deposit coverage (references, abstracts, ORCIDs, funders, licenses, and more) as current/backfile fractions
• Pair with crossref_get_prefix to resolve a DOI prefix to the member ID first

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crossref_get_prefix _tool

• Accepts the registrant prefix of a DOI (e.g. 10.1038, no /suffix)
• Returns the publisher name and numeric member ID — the ID chains directly into crossref_get_member for the full record
• The Crossref prefix record is thin by design (owner name and member link only); richer publisher data lives on the member record

Features

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