How do I check if a specific research paper is available for free?

Use the `get_article_oa_status` tool with the paper's DOI. Your agent will query the Unpaywall database and return the Open Access status along with direct links to the PDF if available.

Does this tool provide legal versions of the papers?

Yes. Unpaywall only indexes legal, author-archived, or publisher-provided Open Access versions of scholarly articles. It does not access pirated content.

What information is required to use this server?

You need the DOI (Digital Object Identifier) of the article and a valid email address to authenticate with the Unpaywall API.

Unpaywall (Open Access Papers) MCP Connector for Claude

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Access millions of open-access scholarly articles. Check OA status and retrieve full-text PDF links using DOIs.

1 tools Official Updated Oct 1, 2026 Official Vinkius Partner

More Details Connect to Claude

Connect to the Unpaywall database to instantly find legal, open-access versions of scholarly papers. This server allows your AI agent to bypass paywalls by locating freely available PDFs and repository versions of research articles using their Digital Object Identifier (DOI).

What you can do

OA Status Verification — Instantly check if a specific scholarly article is available for free under an Open Access license.
PDF Retrieval — Get direct links to legal, full-text PDF versions of research papers hosted on publisher sites or institutional repositories.
Metadata Inspection — Retrieve information about the type of Open Access (gold, green, bronze, etc.) and the hosting source.
Research Automation — Streamline literature reviews by letting your agent automatically find accessible versions of cited works.

How it works

Subscribe to this server
Enter your email address (required by Unpaywall's API policy)
Start searching for open-access papers in Claude, Cursor, or any MCP-compatible client

Who is this for?

Researchers & Academics — quickly find full-text versions of papers without navigating multiple library portals
Students — access required reading materials that are legally available for free
Data Scientists — automate the collection of open-access research data and papers for analysis

open-accessscholarly-articlesacademic-researchdoi-lookuppdf-retrievalresearch-database

Connect to Claude

Subscribe on Vinkius, then add this connector to Claude.ai or Claude Code.

① Claude.ai (web app)

Go to Settings → Connectors → Add custom connector
Paste the MCP endpoint URL below

https://edge.vinkius.com/vk_preview_FhVinYZ5ipCUoRhSWZX441L0cACxRSjvwvPVvMMz/mcp

② Claude Code (terminal)

claude mcp add --transport http unpaywall-open-access-papers https://edge.vinkius.com/vk_preview_FhVinYZ5ipCUoRhSWZX441L0cACxRSjvwvPVvMMz/mcp

③ Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "unpaywall-open-access-papers": {
      "url": "https://edge.vinkius.com/vk_preview_FhVinYZ5ipCUoRhSWZX441L0cACxRSjvwvPVvMMz/mcp"
    }
  }
}

Get full access on Vinkius

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