A good book.
A thought worth
following.
Primer is a place to read closely, select a passage, and explore it with an AI companion that keeps the text in view.
Sample books need no account. Conversation requires a Primer account and CAP’s shared AI allowance.
Begin with what
you want to read.
A book from the shelf
Seven prepared editions, from Alice to Meditations. Open a sample and start reading before you sign up.
Explore the sample booksA book of your own
Import a DRM-free EPUB you have permission to upload, or a converted Primer file. Review the chapters and any linked notes before saving privately.
Finding books for PrimerSomething shorter
Paste an essay or article, or upload a Markdown or plain-text file. Give it a title, review the formatting, and keep it in your private library.
Add a readingStay with the passage.
Select what catches you.
A puzzling sentence. A shift in tone. A thought you don’t want to lose.
Ask your own question.
The selected words stay with your question. Follow a passage citation back into the reading.
Pick up the thread.
Return to your saved conversations and reading notes when you come back.
A little setup.
Then, your next question.
Your Primer account keeps your private readings, notes, and conversations together. You can read and import at any time.
When you want to talk, CAP provides a shared AI allowance of $5 per person per UTC month, with no rollover. Admin credits remain until used. Your allowance covers all CAP apps and depends on the shared sponsor budget.
Chat sends relevant reading text and your question through CAP’s AI proxy to the model provider. Private storage does not mean your text stays only in Primer.
Understand AI, allowance and privacyBefore you begin
Can I try Primer without an account?
Yes. Browse all seven sample books and read them without signing in. Create an account to save your own reading and conversations. Chat uses your shared CAP allowance.
What can I bring into Primer?
DRM-free EPUBs you have permission to upload, converted .primer.json files, Markdown or plain-text files, and pasted text or Markdown. EPUB files can be up to 20 MB; converted files up to 6 MB. Pasted readings can be up to 100,000 characters. Review the import preview: formatting and linked notes depend on the edition. PDF import and fetching articles from a URL are not available.
Does the companion see the whole book?
Prepared sample books use the book text as context. Imported books use a bounded selection of nearby passages and linked notes, rather than the whole book. Responses can be wrong; use passage links to check an interpretation against the text.
Are my imported readings public?
Imported readings belong to your account and do not appear on the public sample shelf. When you chat, relevant text is sent through CAP’s AI proxy to the model provider.
There’s more in the margins.
Bring your curiosity. Sign in with CAP when you’re ready to talk; provider charges may apply.