Research Paper & DOI Lookup (Crossref) MCP Server

by pcp183 Your server? Claim it

not responding

Research Paper & DOI Lookup (Crossref) is listed as active in the registry but did not answer our last check. It exposes 1 tools.

Verify a DOI or find papers via Crossref metadata. $0.005/call via x402.

The linked repository no longer exists on GitHub — it was deleted or made private.

Uptime history 23 days of history · worst day 0%

23 days agonow

0.0%

Uptime 24h

0 of 91 checks

Tools

read from the server

192 ms

Response time

average over 24h

open, no key

Access

streamable-http

What changed 2

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 17 October 2026. No other catalogue keeps this.

17 Oct a tool description was rewritten paper_lookup

17 Oct a tool changed version

Research Paper & DOI Lookup (Crossref) does not always answer

Over the last week it answered 0.0% of our checks. We check every 15 minutes, so you hear about the next outage within the hour — not from your users.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 9 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add paper-lookup --transport http https://paper-lookup-production-56b0.up.railway.app/mcp

Settings → Connectors → Add custom connector, then paste this address

https://paper-lookup-production-56b0.up.railway.app/mcp

~/.codex/config.toml

[mcp_servers.paper-lookup]
url = "https://paper-lookup-production-56b0.up.railway.app/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "paper-lookup": {
      "url": "https://paper-lookup-production-56b0.up.railway.app/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "paper-lookup": {
      "type": "http",
      "url": "https://paper-lookup-production-56b0.up.railway.app/mcp"
    }
  }
}

Available tools 1

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

paper

paper_lookup

Verify a citation or DOI, or find research papers on a topic. Searches Crossref (150M+ records) by DOI, keywords, author or title with year and type filters: title, authors with ORCID, journal or publisher, date, type, ISSN/ISBN, citation and reference counts, licence, full-text links and funders. Abstracts are excluded. Use when an agent must check that a reference exists and is cited correctly. $0.005 per call, USDC on Base (x402).

Endpoints

URL	Transport	State	Latency	Checked
https://paper-lookup-production-56b0.up.railway.app/mcp	streamable-http	answering	192 ms	9 min ago

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Research Paper & DOI Lookup (Crossref) — questions

Answers built from our own checks of this server.

What can Research Paper & DOI Lookup (Crossref) do?

It exposes 1 tools, read directly from the server on our last check. Among them: paper_lookup. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is Research Paper & DOI Lookup (Crossref) working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 0 of 91 checks got a reply (0.0%), average response time 192 ms. The bar chart above shows every period we have measured.

Is Research Paper & DOI Lookup (Crossref) still maintained?

The linked repository no longer exists on GitHub — it was deleted or made private. We show this because it changes what you can expect: an unmaintained server may keep answering for months and then stop without warning.

The registry lists Research Paper & DOI Lookup (Crossref) as active — why does it not respond?

The official MCP registry stores what the author submitted; it does not verify that the server still runs. We check the endpoint ourselves, and this one does not answer. Catalogues that copy the registry without checking will show it as working.

How do I connect Research Paper & DOI Lookup (Crossref)?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does Research Paper & DOI Lookup (Crossref) need an API key?

No. Research Paper & DOI Lookup (Crossref) completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 1 of them are readable on this page. This is what we observed, not what the docs claim.