crossref-mcp-server

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

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What it can do

  • Crossref Get Work: Resolves a DOI to its full Crossref metadata record: title, authors, affiliations, abstract (when deposited), journal or container, publication date, type, license, full-text links,
  • Crossref Get References: Returns the outgoing reference list for a DOI — the works cited by this paper. Each reference includes the raw citation string and, where Crossref has resolved it, a DOI you c
  • Crossref Search Works: Searches the Crossref works index (~155M records) by free text and/or structured filters. Use the filter parameter for structured filtering (object with hyphen-separated Crossre

What data it sees

Do you need an account

No: the server works without sign-in

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

How to connect

How to connect crossref-mcp-server to Claude

The server address to paste into Claude settings:

https://crossref-mcp-server--cyanheads.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect crossref-mcp-server to ChatGPT

The server address to paste into ChatGPT settings:

https://crossref-mcp-server--cyanheads.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect crossref-mcp-server to Cursor

The server address to paste into Cursor settings:

https://crossref-mcp-server--cyanheads.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (5)

Raw names from tools/list. Only developers need these.

crossref_get_workResolves a DOI to its full Crossref metadata record: title, authors, affiliations, abstract (when deposited), journal or container, publication date, type, license, full-text links, funder acknowledgements, and outgoing reference list. The is_referenced_by_count field reports the total incoming citation count from Crossref; the citing works themselves are not available through Crossref — use OpenAlex for citation graphs.
crossref_get_referencesReturns the outgoing reference list for a DOI — the works cited by this paper. Each reference includes the raw citation string and, where Crossref has resolved it, a DOI you can look up with crossref_get_work. Reference list coverage varies by publisher; many older works and non-participating publishers have no indexed references. Incoming citations — the works that cite this paper — are not available through Crossref; use OpenAlex for that.
crossref_search_worksSearches the Crossref works index (~155M records) by free text and/or structured filters. Use the filter parameter for structured filtering (object with hyphen-separated Crossref keys). Sort options: relevance, score, is-referenced-by-count, published, deposited, indexed. Offset-based paging is capped at ~10K results; use cursor="*" to start cursor-based deep paging, then pass the nextCursor value from each response to continue. Cursor and offset cannot be combined.
crossref_search_journalsFinds Crossref journal records by ISSN or title query. Provide issn for an exact single-journal lookup, or query for title-based search returning up to rows results. Set include_works to true to fetch the journal's most recent registered works in a second call (sequential — requires a resolved ISSN from step 1). Returns journal metadata: title, publisher, ISSN-L, subject areas, and total DOI count.
crossref_search_fundersFinds funders registered in the Crossref Funder Registry by name or funder DOI. Provide funder_doi for an exact single-funder lookup (accepts the full DOI like "10.13039/100000001" or just the registry ID), or query for name-based search. Set include_works to true to fetch a paginated list of works funded by the first matched funder (adds a second upstream call). Returns funder name, DOI, country, and alternate names.