# Crossref

`dev.mcpharbor.gateway/crossref`, version 1.0.0

Crossref DOI metadata: citations, journals, funders, bibliometric and scholarly lookups

- MCP endpoint: `https://gateway.mcpharbor.dev/mcp/crossref` for this server alone, or `https://gateway.mcpharbor.dev/mcp` for every server
- Authentication: `Authorization: Bearer <your gateway API key>`
- Price per tool call: $0.0001 (100 micro-USD)
- Registry entry: <https://gateway.mcpharbor.dev/v0.1/servers/dev.mcpharbor.gateway%2Fcrossref/versions/latest>
- Every tool, machine-readable: <https://gateway.mcpharbor.dev/llms-full.txt>

## Provider

We proxy this provider under the terms below, re-checked on a schedule. If a re-check ever
says no, the server and its tools leave the catalog and this page disappears with them.

| Fact | Value |
| --- | --- |
| Terms of use | <https://www.crossref.org/documentation/retrieve-metadata/rest-api/access-and-authentication/> |
| Terms verified on | 2026-09-19 |
| API documentation | <https://www.crossref.org/documentation/retrieve-metadata/rest-api/> |
| Upstream API key | none required |
| Rate limit | 50 requests per minute |
| Website | <https://www.crossref.org/documentation/retrieve-metadata/rest-api/> |
| Compliance notes | mailto joins the polite pool. Abstracts may carry third-party copyright. |

## Attribution

This provider asks for no attribution. Their terms still apply: see the table above.

## Tools (7)

Every call below costs $0.0001 (100 micro-USD). Listing them costs nothing.

| Tool | Description | Price per call | Documentation |
| --- | --- | --- | --- |
| `crossref__crossref_get_member` | Resolves a Crossref member ID to its publisher/organization record: primary name, alternate imprint names, owned DOI prefixes, registered DOI counts, a per-work-type breakdown, and per-category met... | $0.0001 | [crossref__crossref_get_member](https://gateway.mcpharbor.dev/docs/tools/crossref__crossref_get_member) |
| `crossref__crossref_get_prefix` | Resolves a DOI prefix — the registrant portion of a DOI, e.g. "10.1038" — to its owning Crossref member: the publisher name and numeric member ID. Answers "who publishes DOIs starting with 10.1038?... | $0.0001 | [crossref__crossref_get_prefix](https://gateway.mcpharbor.dev/docs/tools/crossref__crossref_get_prefix) |
| `crossref__crossref_get_references` | Returns the outgoing reference list for a DOI — the works cited by this paper. Each reference includes the deposited citation string and, where Crossref has resolved it, a DOI you can look up with ... | $0.0001 | [crossref__crossref_get_references](https://gateway.mcpharbor.dev/docs/tools/crossref__crossref_get_references) |
| `crossref__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, and funder ackn... | $0.0001 | [crossref__crossref_get_work](https://gateway.mcpharbor.dev/docs/tools/crossref__crossref_get_work) |
| `crossref__crossref_search_funders` | Finds funders registered in the Crossref Funder Registry by name or funder DOI. Provide funder_doi for an exact single-funder lookup — the full DOI ("10.13039/100000001"), the bare registry ID ("10... | $0.0001 | [crossref__crossref_search_funders](https://gateway.mcpharbor.dev/docs/tools/crossref__crossref_search_funders) |
| `crossref__crossref_search_journals` | Finds 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. Title-query results page with o... | $0.0001 | [crossref__crossref_search_journals](https://gateway.mcpharbor.dev/docs/tools/crossref__crossref_search_journals) |
| `crossref__crossref_search_works` | Searches the Crossref works index (~155M records) by free text and/or structured filters. The generic query matches loosely across all fields; scope precisely with the field-specific parameters que... | $0.0001 | [crossref__crossref_search_works](https://gateway.mcpharbor.dev/docs/tools/crossref__crossref_search_works) |

## Price

- $0.0001 (100 micro-USD) per tool call.
- Billed on: each tools/call that reaches the upstream and returns a result.
- Free: server/discover, tools/list, registry endpoints, docs files.
- Payment: prepaid credits, drawn down per call. A call your balance cannot cover is refused with HTTP 402 before any upstream is contacted.
- A charged call that then fails upstream is refunded automatically.
- Retries are ordinary calls. There is no client idempotency key, so repeating a request that was already charged buys a second call - see [agent.txt](https://gateway.mcpharbor.dev/agent.txt), section 7.