Concepts
Books vs skills, slugs, versions, and what an access grant is.
bkstr has a small vocabulary. This page defines the terms the rest of the docs lean on. For one-line definitions, see the Glossary.
Books and skills
bkstr sells two classes of content. They are bought and fetched the same way; they differ in what your agent does with them.
- A book is a bundle of markdown — chapters of prose your agent reads as context. Books support an optional question-and-answer endpoint that grounds answers in the book's text.
- A skill is a
.zipbundle — aSKILL.mdplus supporting files (scripts, configs, templates) your agent installs and runs.
| Book | Skill | |
|---|---|---|
| Content | Markdown chapters | SKILL.md plus supporting files |
| Your agent | Reads it as context | Installs and runs it |
| Delivered as | A bundle of files | A bundle of files |
| Question-and-answer endpoint | Yes | No |
The catalog treats them as one product type — the buy-and-fetch flow is identical. Only the install destination and how your agent uses the files differ.
Slugs and the catalog
Every item has a slug — a short, lowercase, hyphenated identifier such as agentic-qa-manual. The slug is how every surface names an item: the storefront URL /storefront/<slug>, the install endpoint, the CLI.
The catalog is the set of active items, browsable at /storefront. bkstr resolves a slug to either a book or a skill — whichever is active under that slug. Archived items do not resolve; a request for one is a not-found.
Versions
Books and skills are versioned — v1, v2, v3. The latest version is the one served by default. Your purchase covers every version of the item you bought, so you can re-fetch after the publisher ships an update at no extra cost.
A publisher who re-uploads identical content gets the same version back — the upload is idempotent. An upload with changed content creates the next version.
Access grants and ownership
Owning an item means your account holds a live access grant for it. A grant records that your account may fetch a specific book or skill.
A grant is created when:
- you complete a purchase — the grant is tied to your Stripe payment;
- you are the publisher of the item — publishers hold a grant on their own content;
- an admin grants you access directly.
A grant is live until it is revoked. It does not expire on its own, and re-fetching never consumes it. An admin can revoke a grant — for example, to reverse an accidental purchase — which ends access while keeping the record.
Free items are never granted. An item priced at $0 is installable by anyone, anonymously. Because nobody holds a grant for it, a free item never appears in a Library or in bkstr list — it is installable by everyone and owned by no one.
Archived items
A publisher can archive a book. An archived item is hidden from the storefront, the catalog, and bkstr list, and it no longer resolves by slug for browsing. Archiving does not revoke grants — anyone who already owns an archived book keeps access and can still install it by its slug.