Unpaywall API

api.unpaywall.org · Science

Science No Auth Free & Open Academic Research Open Access

For any DOI, find out if a free legal full-text version of the paper exists anywhere on the web. Covers 50+ million papers. Requires only your email address — no API key.

Authentication

No authentication requiredFree to use with no key needed.

Sample Requests

GET Check open access for a DOI

Find free legal full-text for a paper DOI.

https://api.unpaywall.org/v2/10.1038/nature12373?email=[email protected]

Hover any highlighted part to learn what it does

curl -X GET "https://api.unpaywall.org/v2/10.1038/nature12373?email=you%40example.com"

import requests
params = {
    "email": "[email protected]"
}
response = requests.get(
    "https://api.unpaywall.org/v2/10.1038/nature12373",
    params=params,
)
print(response.json())

const url = new URL('https://api.unpaywall.org/v2/10.1038/nature12373');
url.searchParams.set('email', '[email protected]');

const response = await fetch(url); 
const data = await response.json();
console.log(data);

package main

import (
	"fmt"
	"io"
	"net/http"
	"net/url"
)

func main() {
	baseURL, _ := url.Parse("https://api.unpaywall.org/v2/10.1038/nature12373")
	q := baseURL.Query()
	q.Set("email", "[email protected]")
	baseURL.RawQuery = q.Encode()
	targetURL := baseURL.String()
	req, _ := http.NewRequest("GET", targetURL, nil)

	client := &http.Client{}
	resp, _ := client.Do(req)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

require "net/http"
require "json"

uri = URI("https://api.unpaywall.org/v2/10.1038/nature12373")
uri.query = URI.encode_www_form({
  "email" => "[email protected]"
})

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"

req = Net::HTTP::Get.new(uri)

res = http.request(req)
puts JSON.parse(res.body)

<?php
$url = "https://api.unpaywall.org/v2/10.1038/nature12373?" . http_build_query([
    "email" => "[email protected]"
]);
$opts = ["http" => [
    "method" => "GET",
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));

Postman Setup Guide

Get Postman ↗

No API key needed — just pass your email
Try GET https://api.unpaywall.org/v2/10.1038/[email protected]
Check is_oa field in response: true means a free version exists
best_oa_location.url_for_pdf gives the direct PDF link

Open documentation ↗