Glossary: Capa docs

The admin and these docs say project and entry. Parts of the API, older code and some error messages say tenant and instance. They mean the same things.

Term	Means
Project	One site's space in Capa: its models, entries, media, keys and members. The API calls it a tenant. See Projects.
Model	A content type you define, such as Article. The API sometimes calls it a data model.
Namespace	A model's or a field's name in the API, such as `article` or `hero_image`. Lowercase, unique within its project or model.
Field	One value on a model: text, a number, an image, a link. See Content model.
Entry	One piece of content of a model. The API calls it an instance: the `instance:read` scope reads entries, and `instance.published` is the webhook event for a publish.
Version	One saved state of an entry. Every save makes a new one, and one of them is live.
Draft	An entry, or a version of one, that is not live. Only draft keys can read it.
Published	Live. Production keys read the published version.
Published, draft ahead	Live, with saved changes that are not live yet. The API's `status` for it is `changed`.
Relation	A field that links to entries of another model, such as an article's author.
Expand	Ask for a related entry's own fields in the same read: `select=title,author(name)`.
Select	The `select` parameter: which fields a read returns.
Key	The credential your code reads with, sent in `x-api-key`. See Keys.
Scoped key	A key starting `cap_live_` or `cap_test_`. It carries scopes and works on `/api/`.
Legacy key	A key starting `pk_` or `sk_`, or an older key with no prefix. It works on `/v2/api`, `/v3/api` and `/api/`.
Production key	A key that reads published entries only: `cap_live_` or `pk_`. Its reads are cached.
Draft key	A key that reads drafts too: `cap_test_` or `sk_`. The API reports its environment as something other than `production`. Never cached.
Scope	One permission on a scoped key, written `resource:action`, such as `instance:read`.
Version (API)	The dated contract a read follows, such as `2026-10-01`, sent in `Capa-Version`. See Versions.
Surrogate key	A tag on a cached response that names what it holds, so a publish purges exactly the responses that showed the entry. See Caching.
Purge	Clearing cached responses. Publishing purges what changed.
Workspace	An arrangement of the admin's sidebar: folders and shortcuts. Moving things in it never moves content.
Layout	How a model's entries are arranged in the editor: cards, columns and widths.
Owner	The one person in a project who can transfer it or delete it.
Role	What a member may do: Admin, Developer, Content or Viewer. See Members and roles.
Legacy API	`/v2/api` and `/v3/api`, the read API existing sites use. It keeps working.