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Unpaywall

The Unpaywall REST API gives anyone free, programmatic access to the Unpaywall database of open access scholarly articles. The database covers over 120 million articles with Crossref DOIs and provides free, legal full-text links where available, with metadata on OA status (gold, hybrid, bronze, green), host type (publisher, repository), version (published, accepted, submitted), and license information.

1 APIs 0 Features
Open AccessScholarly ArticlesResearchAcademicLibrariesDOIScience

APIs

Unpaywall API

Free REST API providing open access status and full-text links for 120M+ scholarly articles. Look up any article by DOI to get its OA status, best open access location (publishe...

Collections

Pricing Plans

Unpaywall Plans Pricing

3 plans

PLANS

Rate Limits

Unpaywall Rate Limits

5 limits

RATE LIMITS

FinOps

Semantic Vocabularies

Unpaywall Context

8 classes · 37 properties

JSON-LD

API Governance Rules

Unpaywall API Rules

6 rules · 2 errors 3 warnings 1 info

SPECTRAL

JSON Structure

Unpaywall Article Structure

0 properties

JSON STRUCTURE

Example Payloads

Unpaywall Get Doi Example

2 fields

EXAMPLE

Unpaywall Search Example

2 fields

EXAMPLE

Resources

👥
GitHubOrganization
GitHubOrganization
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LinkedIn
LinkedIn
🔗
Website
Website
🔗
Documentation
Documentation
🔗
DataFormat
DataFormat
💬
Support
Support
🔗
Vocabulary
Vocabulary
🔗
JSONLDContext
JSONLDContext
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LlmsText
LlmsText

Sources

Raw ↑
opencollection: 1.0.0
info:
  name: Unpaywall API
  version: 2.0.0
items:
- info:
    name: DOI Lookup
    type: folder
  items:
  - info:
      name: Get Open Access Status by DOI
      type: http
    http:
      method: GET
      url: https://api.unpaywall.org/v2/:doi
      params:
      - name: doi
        value: 10.1038/nature12373
        type: path
        description: The DOI of the article (e.g., 10.1038/nature12373)
      - name: email
        value: you@example.com
        type: query
        description: Your email address — required for all API calls to identify usage
    docs: Retrieve open access information for a scholarly article identified by its DOI. Returns the OA status, best open
      access location, all available OA locations, journal metadata, and author information.
- info:
    name: Search
    type: folder
  items:
  - info:
      name: Search Articles by Title
      type: http
    http:
      method: GET
      url: https://api.unpaywall.org/v2/search/
      params:
      - name: query
        value: machine learning drug discovery
        type: query
        description: Title search query. Supports AND (default), OR, phrase matching ("exact phrase"), and negation (-term).
      - name: email
        value: you@example.com
        type: query
        description: Your email address — required for all API calls
      - name: is_oa
        value: 'true'
        type: query
        description: Filter results to open access articles only (true) or closed access only (false)
      - name: page
        value: '1'
        type: query
        description: Pagination page number (50 results per page)
    docs: Search the Unpaywall database by article title. Returns up to 50 matching articles per page with relevance scores
      and title snippets. Covers 120M+ articles with Crossref DOIs updated within 24 hours. Supports AND logic (default),
      phrase matching (quoted), OR operator, and negation (-term).
bundled: true