Finding books for Primer

Start with Primer's seven sample books, or bring a DRM-free EPUB you are allowed to store and process in Primer. EPUB is the supported ebook format; PDF, Kindle formats and scanned documents are not currently supported. Text and Markdown can be pasted into Add a reading.

Project Gutenberg

Find a title on Project Gutenberg, open its book page, and choose an EPUB download. Save the file on your device, then select it in Primer's Add a reading form and review the conversion before saving.

Most Gutenberg books are public domain in the United States, but some remain copyrighted. Check the specific edition's notice, including any translation or illustrations, and the rules in your country. Gutenberg's name and distribution license also have separate conditions. Permissions guidance.

Standard Ebooks

Browse Standard Ebooks, choose a title, and select its EPUB download. Its carefully prepared editions are a useful source of reflowable text.

Standard Ebooks bases its public-domain assessment on United States law and dedicates its own contributions to the public domain. Check the position in your own jurisdiction before reuse. About Standard Ebooks.

The Anarchist Library

The Anarchist Library offers essays and books in several downloadable formats, including EPUB. Open an individual work and choose its EPUB option for Primer; use pasted text for a short essay when appropriate. Available formats.

The archive encourages distribution, but its availability statement is not an edition-by-edition finding that every work is public domain or permission for every hosted or model-processing use. Inspect the work's source and rights information. Do not treat the entire catalog as material Primer can redistribute.

Buying ebooks: check more than the file format

Some publishers sell downloadable DRM-free EPUBs. Before buying a book for Primer, confirm both that you will receive an EPUB file and that its terms permit your intended hosted storage and model use. DRM-free describes a technical restriction; it does not grant redistribution or upload permission.

For example, Verso sells watermarked, DRM-free EPUBs directly, but its purchase help says those ebooks cannot be uploaded to websites or file-sharing networks. We cannot recommend importing a Verso purchase into Primer without resolving that permission question, even though its file format is technically compatible. A private library does not by itself settle this restriction. Verso purchase help, ebook file types, terms of service.

Before selecting a file

• Download the actual .epub to a location you can find in your device's file picker. On a phone, you may need to save it to Files or Downloads first.
• An .acsm file is not an EPUB book. A purchase delivered only inside a reading app may not provide an importable file. Primer does not remove DRM.
• Keep the original. Preview sections and footnotes, and read conversion warnings before saving; Primer preserves supported embedded raster illustrations, but does not reproduce the original page layout. Unsupported or oversized images retain descriptions and a warning.
• The EPUB limit is 20 MB; the converted package limit is 6 MB. Embedded images are limited to 200 PNG, JPEG, GIF or WebP assets, 1.5 MB each and 3 MB combined before encoding. A very large or heavily illustrated book may not fit even if it opens in another reader.
• Uploading to your private Primer account does not publish the book on the public shelf. Chatting still sends relevant text through CAP’s AI proxy to the selected model provider.

See Getting started for the import steps and AI through CAP for the chat data flow.

Source information checked 2026-09-06. Download options and publisher terms can change; check the linked source before purchasing or importing.