crossref-mcp

English | 中文

An MCP server wrapping the Crossref REST API, exposing scholarly-metadata lookups (works, members, journals, funders, types, licenses, prefixes) as tools an LLM client can call.

Not affiliated with or endorsed by Crossref. Data is served live from the public Crossref API. Set CROSSREF_MAILTO to join Crossref's polite pool.

Features

• All major Crossref resource endpoints as 18 read-only tools.
• Dual transport: stdio (local) and Streamable HTTP (container).
• Polite pool (User-Agent + mailto), optional Crossref Plus token.
• Token-bucket rate limiting (auto-tuned from X-Rate-Limit-* headers) with exponential backoff honoring Retry-After.
• Cursor deep paging, field select, raw vs simplified output.
• Optional X-API-Key HTTP auth (/health exempt), /health endpoint.
• Optional Redis response cache + cross-replica rate limiting.
• Optional Caddy TLS reverse proxy for public deployment.

Quick start (local, stdio)

uv sync
export CROSSREF_MAILTO="you@example.com"   # recommended (polite pool)
uv run crossref-mcp                         # starts a stdio MCP server

Inspect with the MCP Inspector: uv run mcp dev src/crossref_mcp/server.py.

Configuration

Tools

Works — search_works, get_work (by DOI), get_work_references (capped at 50), get_work_quality (registration agency). Members / Journals / Funders — search_members · get_member · get_member_works; search_journals · get_journal (ISSN) · get_journal_works; search_funders · get_funder · get_funder_works. Types / Licenses / Prefixes — list_types · get_type; list_licenses; get_prefix. Plus ping.

Shared parameters. Search/list tools take query (and query_bibliographic / query_author / query_title on works), filter (Crossref key:value,… syntax), sort + order, rows (≤1000) + offset, and select. Deep paging: set cursor="*" then reuse the returned next_cursor. All tools return simplified fields by default; pass raw=true for the full Crossref JSON.

Connecting an MCP client

stdio (Claude Desktop / Cursor) — claude_desktop_config.json:

{
  "mcpServers": {
    "crossref": {
      "command": "uvx",
      "args": ["crossref-mcp"],
      "env": { "CROSSREF_MAILTO": "you@example.com" }
    }
  }
}

Or run the container over stdio: "command": "docker", "args": ["run", "-i", "--rm", "-e", "CROSSREF_MAILTO", "heyinnaneo/crossref-mcp"].

Streamable HTTP — once the container is up, point an HTTP-capable client at `http://localhost:8000/mc

... View full README on GitHub