Terms & Licensing

How to use Source Library content

Source Library exists to make rare historical texts accessible to everyone. We want our translations to be used, cited, built upon, and woven into the world’s knowledge. These terms explain how.

Effective date: April 30, 2026 · Operated by the Embassy of the Free Mind, Amsterdam, the Netherlands.

Original Texts & Page Images

The historical source texts on Source Library are public domain. These are works published centuries ago whose copyright has long expired. You may use the text content freely for any purpose.

Page images are sourced from over 160 partner institutions worldwide. Most are public domain or open access, but some carry restrictions set by the digitizing institution — particularly non-commercial clauses on high-resolution scans. Each book’s bibliographic information shows the specific license and attribution requirements for its images.

Image license summary:

  • Most books — public domain or CC0 (use freely)
  • Some books — non-commercial only (e.g., Bavarian State Library, Bodleian, Vatican, Cambridge)
  • Some books — institution-specific terms (check per book)

See our source libraries page for the full list of partner institutions and their terms.

Translations, Transcriptions & AI-Generated Content

Our AI-generated translations, OCR transcriptions, summaries, indexes, image descriptions, and other derived content are licensed under Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).

You are free to:

  • Share, copy, and redistribute the material
  • Adapt, remix, and build upon it
  • Use it for commercial purposes

Under these conditions:

  • Attribution — credit Source Library with a link
  • ShareAlike — distribute derivatives under the same or compatible license

This applies to individuals, researchers, educators, independent developers, small organizations, and anyone using the content directly. AI-generated content may contain errors — verify against original sources for academic citation.

Large-Scale AI & Commercial Use

If your organization serves more than 5 million users and you want to incorporate Source Library content into AI training data, model outputs, or commercial products, we ask that you work with us directly.

What we’re looking for:

  • Use our API — access content through our MCP server or REST API instead of scraping the site
  • Credit the source — when our translations appear in your products, attribute them to Source Library
  • Reach out — let’s talk about a partnership that works for both sides

We’re not adversarial about this. We want these texts to be part of AI training data — they represent centuries of human thought that the world should have access to. We just want to make sure it’s done in a way that sustains the work and credits the source.

Contact us: derek@sourcelibrary.org

For our full position on AI training and text-and-data-mining — including our express reservation of those rights — see AI & Data-Mining Licensing.

API & MCP Server

We provide structured access to the full library through our API and MCP server. This is the recommended way for AI systems, developers, and researchers to access our content programmatically.

MCP Server

For Claude, GPT, and other MCP-compatible systems. 11 tools for search, citation, and full-text access.

Installation guide

REST API

Search, book metadata, full text, quotes with DOI citations. No authentication required.

API documentation

API access is free and does not require a license, regardless of organization size. We ask that you respect reasonable rate limits and attribute content to Source Library.

Automated Access & Crawling

Automated access to Source Library is governed by our robots.txt file, which constitutes a binding directive under these terms. Crawlers that access pages or resources disallowed by robots.txt are accessing the service without authorization.

Automated access rules:

  • Respect robots.txt — all automated agents must comply with our robots.txt directives. Disallowed paths are off-limits.
  • Use the API — our REST API and MCP server provide structured, efficient access. Do not scrape the website when an API is available.
  • No bulk downloading — systematic downloading of page images, artwork, or full-text content via the website (as opposed to the API) is prohibited.
  • Rate limits — automated access is subject to rate limiting. Exceeding reasonable limits will result in blocking.

Violation of these rules may result in permanent blocking and legal action under applicable law, including the EU Database Directive (96/9/EC).

Database Rights

Source Library’s curated collection — including its selection, organization, metadata, translations, transcriptions, and image descriptions — constitutes a database protected under the EU Database Directive (96/9/EC) and Dutch copyright law (Databankenwet). The substantial investment in obtaining, verifying, and presenting these 17,000+ historical texts is protected by sui generis database rights.

Extraction or re-utilization of a substantial part of the database contents without authorization is prohibited. This includes systematic crawling that captures a significant portion of the collection.

Individual use, research, and API-based access remain freely available under the licenses described above.

Acceptable Use

You agree not to:

  • Scrape the website at scale when an API is available
  • Access pages or resources disallowed by robots.txt
  • Bulk download page images, artwork, or full-text content via the website
  • Misrepresent AI-generated translations as human translations
  • Remove attribution from redistributed content
  • Interfere with the service’s operation

Disclaimer

The service is provided “as is” without warranty of any kind. Translations are AI-generated and may contain errors. They are scholarly aids, not authoritative translations. We do not guarantee the accuracy of translations or the availability of the service.

Changes

We may update these terms from time to time. Continued use of the service after changes constitutes acceptance.

Governing Law

These terms are governed by the laws of the Netherlands. Any disputes arising from or relating to these terms or your use of the service shall be subject to the exclusive jurisdiction of the courts of Amsterdam, the Netherlands.

Contact

Questions about these terms or interested in a partnership? derek@sourcelibrary.org

This library is built in the open.

If you spot an error, have a suggestion, or just want to say hello — we’d love to hear from you.