Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@unpaywall-mcp Look up DOI 10.1038/s41586-023-00000-0"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
Unpaywall Open Access scholarly API MCP server. Looks up free-to-read versions of papers by DOI and searches article titles for OA matches.
Related MCP server: OpenAlex MCP Server
Tool | Parameters | Description |
|
| OA status + bibliographic metadata for a single DOI |
|
| Search article titles; returns up to 50 DOI objects per page |
search_articles query modifiers: "quoted phrase" (contiguous), OR
(either term), -term (exclude). is_oa tri-state: None no filter, True
OA only, False non-OA only.
Variable | Required | Description |
| yes | Contact email Unpaywall requires on every request |
Unpaywall rate limit: 100,000 calls/day per email.
Only requirement: uv (https://docs.astral.sh/uv/). Nothing else to install.
claude mcp add unpaywall-mcp -e UNPAYWALL_MCP_EMAIL=<your-email> -- uvx --from git+https://github.com/dam2452/unpaywall-mcp.git unpaywall-mcp{
"mcpServers": {
"unpaywall-mcp": {
"command": "uvx",
"args": ["--from", "git+https://github.com/dam2452/unpaywall-mcp.git", "unpaywall-mcp"],
"env": { "UNPAYWALL_MCP_EMAIL": "<your-email>" }
}
}
}After pushing a new version: uv cache clean and restart the client.
uv run --directory . unpaywall-mcpTests (manual):
uv run --directory . --with pytest pytest test/Look up Open Access status and bibliographic metadata for a single DOI.
Returns the full Unpaywall DOI object: title, authors, publication info, OA status, best OA location (free PDF link if available), and more.
Examples: get_doi(doi="10.1038/nature12373") get_doi(doi="10.1007/s11222-022-10107-2")
Inputs: doi (required). Returns: object
Search Unpaywall article titles and return matching DOI objects.
Search terms are whitespace-split and AND-ed by default. Modifiers inside
query:
"quoted phrase" : words must appear as a contiguous phrase
OR : match either term (replaces default AND)
-term : exclude titles containing this term
Returns up to 50 results per page, sorted by match score. Each result
contains the full DOI object, a numeric score, and an HTML snippet
showing where the query matched the title.
Examples: search_articles(query="cell thermometry") search_articles(query='single "cell thermometry"', is_oa=True) search_articles(query="machine learning OR deep learning", is_oa=False, page=2)
Inputs: query (required), page, is_oa. Returns: object
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
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Scored across 2 tools
The two tools have clearly distinct purposes: get_doi retrieves data for a known DOI, while search_articles finds articles by title query. No overlap or ambiguity.
Both tools follow a consistent verb_noun pattern: get_doi and search_articles. The naming is predictable and easy to understand.
Two tools is lean but reasonable for a focused API that covers the primary use cases: fetching by DOI and searching by title. Could be expanded with additional identifiers, but the count is appropriate for a minimal server.
The server covers the core functionality of the Unpaywall API: single DOI lookup and title search. Minor gaps exist (e.g., no batch operations or search by other metadata), but the main workflows are supported.
Unpaywall MCP — open-access lookup for scholarly papers (free, no key)
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