Crossref vs Opencitations

In-depth architectural comparison of the Crossref and Opencitations MCP servers. Compare execution transports, security boundaries, tool capabilities, quality scores, and ready-to-paste client installation snippets for Claude, Cursor, Windsurf, and VS Code.

Which MCP Server Should You Choose?

Choose Crossref when:

• You need dedicated capabilities in the Research domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Free / Open Source).
• Primary tools included: DOI metadata lookup, Crossref work search, Author and ORCID discovery.

Explore Crossref Details

Choose Opencitations when:

• You need dedicated capabilities in the Research domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Free / Open Source).
• Primary tools included: Look up cited DOIs, Find citing DOIs, Count incoming citations.

Explore Opencitations Details

Feature & Specification Comparison

Specification	Crossref Research	Opencitations Research
Summary	Crossref MCP — wraps the Crossref REST API (academic papers, free, no auth)	OpenCitations COCI — open-license citation index by DOI
Category & Scope	Research	Research
Quality signal

Tools & Capabilities Breakdown

Ready-to-Paste Client Configurations

Paste either (or both) of these JSON server blocks into your client config file (e.g. claude_desktop_config.json or ~/.cursor/mcp.json).

{
  "mcpServers": {
    "crossref-2": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-crossref"
      ]
    }
  }
}

{
  "mcpServers": {
    "opencitations": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-opencitations"
      ]
    }
  }
}

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