Who may talk to an embedded editor

The rules

• Only the page that embeds it. A message from any other window, such as a sibling frame or a popup, is ignored.
• Only an allowed origin. If the iframe's address names origins (origin=), nothing else is ever accepted. The first hello from an allowed origin pins it: from then on only that origin, and every reply and event is posted to that origin, never to "*". With no origin in the address, the first handshake's origin is the one pinned.
• Nothing before the handshake. Any request other than hello from an unpinned origin is ignored.
• A stranger gets no answer at all, not even a refusal, so a page cannot find out that an editor is there.

athanor-embed.js follows the same rules from your side: it posts only to the editor's origin and accepts messages only from its own iframe at that origin.

What an embedded editor does not do

• It saves nothing on the reader's device and never touches the reader's own Athanor documents: no autosave, no backups, no tabs. Read the structure out through the protocol and keep it where your page keeps things.
• It shows no account, sign-in or cloud features, and no assistant.
• It does not navigate away: the small Athanor mark in its corner opens the Athanor site in a new tab.

The site sends no frame-ancestors or X-Frame-Options, so any page may frame the editor; who may talk to it is the origin rule above.