# crossref-mcp-server MCP Server

Resolve DOIs, search ~155M scholarly works, and fetch references via the Crossref REST API.

**Publisher claimed.** No tool list reported, and Pod has not connected to this server.

## Status

Pod has not dialled crossref-mcp-server yet, so everything on this page is what its publisher reported rather than what we observed. Registries describe servers; they do not connect to them. Until a check runs, treat the tool list below as a claim.

## Connect

Published as `@cyanheads/crossref-mcp-server` on npm. Runs locally.

## Known issues

**57 problems reported by people outside the maintainer team.** Issues filed by the project's own owners, members and collaborators are excluded — those are release checklists and internal refactors, not things that will go wrong for you. Showing 12.

### Most discussed

### bug(crossref_search_works): fields projection can exclude required output fields

### Server version

0.1.3

### mcp-ts-core version

0.9.6

### Runtime

Bun 1.3.11

### Transport

HTTP (Streamable HTTP)

### OS

macOS 15.x

### Description

`crossref_search_works` returns `isError: true` with a serialization error when the `fields` input array omits `type`. The Crossref `select=` projection removes `type` from the upstream response, but `WorkSummarySchema` declares `type: z.string()` as required. The handler maps `type: raw.type` unconditionally, so when `raw.type` is `undef

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/1) · 2026-05-23 · closed · 5 comments

### bug(get_work,search_works): an alternatives wrapper renders one formula twice

### Server version

0.3.6

### mcp-ts-core version

0.11.1

### Runtime

Bun

### Runtime version

Bun 1.3.14

### Transport

HTTP

### OS

macOS

### Description

Related: #54

A JATS `<alternatives>` wrapper holds several encodings of one object and expects a consumer to pick one. In an abstract it wraps a formula's presentation MathML beside the same formula's TeX, or a graphic beside its TeX. The markup strip has no rule for it, so every child that carries text is emitted and one expression 

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/56) · 2026-08-10 · closed · 4 comments

### bug(response-parity): content output truncates references and abstracts

### Server version

0.2.0

### mcp-ts-core version

0.10.14

### Runtime

Bun

### Runtime version

Bun 1.3.14

### Transport

HTTP (Streamable HTTP)

### OS

macOS 26.1

### Description

`crossref_get_references` and `crossref_search_works` return less data through `content[]` than through `structuredContent`. Content-only MCP clients therefore lose references, citation text, or most of an abstract with no equivalent retrieval path.

### Steps to reproduce

1. Call `crossref_get_references` wit

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/31) · 2026-07-16 · closed · 3 comments

### bug(get_work): the publication-date fallback chain diverges from the three search tools

### Server version

0.3.7

### mcp-ts-core version

0.11.1

### Runtime

Bun

### Runtime version

Bun 1.3.14

### Transport

HTTP

### Description

Related: #58

The four tools that resolve a publication date call the same helper but chain their fallbacks at different points, so they can disagree about the same record.

`crossref_get_work` picks the source object first and parses once:

```ts
parseDateParts(raw.published ?? raw['published-print'] ?? raw['published-online'] ?? raw.issued)
```

`

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/59) · 2026-08-10 · closed · 2 comments

### bug(get_work): funder, affiliation, and date projections assume upstream fields Crossref does not guarantee

### Server version

0.3.7

### mcp-ts-core version

0.11.1

### Runtime

Bun

### Runtime version

Bun 1.3.14

### Transport

http

### Description

`crossref_get_work` fails the whole call on three upstream shapes the Crossref message schema permits and the projection treats as impossible. All three are ordinary deposits, not corruption.

Related: #6, which closed the same class for `type: null`.

1. **A funder identified by ROR instead of by name.** Crossref lets a funding assertion carry `id:

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/58) · 2026-08-10 · closed · 2 comments

### Most recent

### bug(search_works): a zero-result response leads with an empty text block

### Server version

0.3.9

### mcp-ts-core version

0.12.3

### Runtime

Bun

### Runtime version

Bun 1.4.0

### Transport

http

### Description

When a query matches nothing, `format()` in `search-works.tool.ts` builds `lines` from the works array and an optional `nextCursor` header — both empty — and returns `''`. That empty string still ships as `content[0]`, ahead of the enrichment trailer that carries the useful "No results matched the query" notice.

The information is all there; the res

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/61) · 2026-08-25 · open · 0 comments

### bug(search_journals,search_funders): works_cursor paging is rejected by Crossref — an explicit sort rides along with the cursor

### Server version

0.3.9

### mcp-ts-core version

0.12.3

### Runtime

Bun

### Runtime version

Bun 1.4.0

### Transport

http

### Description

Related: #38

`works_cursor` never works on either tool. `getJournalWorks` and `getFunderWorks` both build their query string with a hardcoded `sort: 'published', order: 'desc'`, then call `setSubResourcePage(params, opts)`, which appends `cursor` when the caller passes one. Crossref rejects `sort` combined with `cursor` outright, so every cursor cal

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/60) · 2026-08-25 · open · 0 comments

### enhancement(get_references): refersplit and valueless-attribute tags survive the markup strip

Related: #50

Two brackets `stripReferenceMarkup` does not recognize still reach both result surfaces. Both are well-formed markup by the rule's own shape test, so neither is a case the "an ambiguous angle bracket must not cost the reader content" constraint argues for leaving.

### `<refersplit />` is not on the allow-list

A reference-separator element some publishers append to each packed citation string. It is self-closing, carries nothing in an attribute, and has no ordinary-word reading, s

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/52) · 2026-08-10 · closed · 2 comments

### bug(text-normalization): only five named HTML entities are decoded; the rest reach both surfaces literally

### Server version

0.3.5

### mcp-ts-core version

0.11.1

### Runtime

Bun

### Runtime version

Bun 1.3.14

### Transport

HTTP

### OS

macOS

### Description

`decodeHtmlEntities` in `src/services/crossref/crossref-service.ts` decodes five named entities — `&amp;`, `&lt;`, `&gt;`, `&quot;`, `&apos;` — plus numeric and hex references. Every other named entity a publisher deposits reaches both result surfaces as its literal source text.

It is the same pass all three normalization functions s

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/51) · 2026-08-10 · closed · 2 comments

### enhancement(get_references): the markup allow-list misses span, inf, and the JATS structured-citation vocabulary

Related: #49

The element-name allow-list in `normalizeReferenceText` clears inline emphasis, scripts, block boundaries, and MathML, but three element classes it does not name still reach both result surfaces as visible tags. None of them carries content in an attribute, so the constraint #49 established — an ambiguous angle bracket must not cost the reader a URL — does not argue for leaving them.

Reproducible against the live API, one `curl` each:

```
curl -s 'https://api.crossref.org/works/1

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/50) · 2026-08-09 · closed · 2 comments

### enhancement(get_references): reference free text carries raw markup; angle brackets are ambiguous there

Related: #44

`crossref_get_references` projects `unstructured`, `articleTitle`, `journalTitle`, and `author` through `normalizeText()` — entity decode and whitespace collapse, no markup stripping. A measurable slice of entries therefore reaches both result surfaces carrying raw markup.

Two live entries, each one `curl` away:

```
curl -s 'https://api.crossref.org/works/10.3934/dcds.2013.33.2211' | jq -r '.message.reference[0].unstructured'
# J. T. Beale, T. Kato and A. Majda, <em>Remarks on th

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/49) · 2026-08-09 · closed · 2 comments

### bug(get_member,get_prefix): publisher/member names never get HTML entity decoding

### Server version

0.3.3

### mcp-ts-core version

0.11.1

### Runtime

Bun

### Runtime version

Bun 1.3.14

### Transport

HTTP (Streamable HTTP)

### Description

`crossref_get_member`'s `primaryName`/`names` and `crossref_get_prefix`'s `ownerName` project `raw['primary-name']`/`raw.names`/`raw.name` with no post-processing at all — neither file imports `decodeHtmlEntities` or `stripJats` from `crossref-service.ts`. Every other name-bearing surface in the server (work titles, journal titles,

[Read the thread](https://github.com/cyanheads/crossref-mcp-server/issues/48) · 2026-08-09 · closed · 2 comments

[See all 18 reports Pod holds for crossref-mcp-server](/mcp/crossref-mcp-server/issues) — of 57 qualified upstream.

## Firsthand observations

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