How a component joins Issho: the same issho option in every component (Kotoba's editor, Hakushi's canvas, Masu's grid, yours), so an app writes it once and it means the same everywhere.

<.kotoba    issho={[instance: MyApp.Issho, document: "page:1/body"]} user={@user} />
<.canvas    issho={[instance: MyApp.Issho, document: "page:2"]} user={@user} />
<.data_grid issho={[instance: MyApp.Issho, document: "page:3/rows"]} user={@user} />

The keys:

• :instance (required): your Issho instance, MyApp.Issho.
• :document (required): the document the component shows. Its room is the part before the first "/" ("page:1/body" is in "page:1"), so the components of a page whose documents share a room share its people, and a pointer goes from one to the other.
• :can: :write (the default) or :read, what the person may do here; your policy is asked as well.
• :people: whether the component shows the room's people itself (true); false on a page that shows Issho's list (Issho.Components.people/1).
• :follow: whether the component takes part in following (true); false, and it follows no one and shows no one followed, though the room's other components do.
• :on_behalf_of: the person an actor acts for (an agent's person).
• :claims: what your policy needs to know of the actor, signed in its grant.

A component takes its own options besides these (Kotoba's :undo), and says which with new!/2's extra; any other key is an error, so a typo does not go unnoticed. The person is the component's user, as Issho.Actor says them.