Unpaywall

live Research

Find free legal copies of paywalled papers by DOI. No API key — uses a polite-pool email.

2 tools
0ms auth
free tier 50 calls/day
🔑 Authentication

Unpaywall requires a contact email (polite-pool identifier). The gateway can supply one, or BYO via _email query param.

Config with credentials 
{
  "mcpServers": {
    "pipeworx-unpaywall": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote@latest",
        "https://gateway.pipeworx.io/unpaywall/mcp?_email=you%40example.com"
      ]
    }
  }
}

Generate an app password →

Tools

get_oa required: doi

OA status + best free copy for a DOI.

Parameters
Name Type Description
doi req string DOI
▶ Try it
search_papers required: query

Keyword search; optionally OA-only.

Parameters
Name Type Description
query req string Search term
is_oa opt boolean OA only
page opt number 1-based page
▶ Try it

Test with curl

The gateway speaks JSON-RPC 2.0 over HTTP POST. You can test any pack directly from the terminal.

List available tools
bash 
curl -X POST https://gateway.pipeworx.io/unpaywall/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'
Call a tool
bash 
curl -X POST https://gateway.pipeworx.io/unpaywall/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"get_oa","arguments":{"doi": "10.1038/nature12373"}}}'

Use with the SDK

Install @pipeworx/sdk to call tools from any TypeScript/Node project.

TypeScript 
import { Pipeworx } from '@pipeworx/sdk';
const px = new Pipeworx();
const result = await px.call("get_oa", {"doi":"example"});
ask_pipeworx 
// Or ask in plain English:
const answer = await px.ask("find free legal copies of paywalled papers by doi");