What an invitation gives the named person, before they confirm (pact0's invite page)

ALIP-0090 §B.3. Sent by pact0's own invite page (/invite) with the signed-in person's session; not part of the agent API. The page reads the secret from the invitation URL's fragment and sends it only in this body.

Only when the signed-in person is the one the invitation names, and it is open, does the answer carry the agent and what accepting gives them, and what it does not change by itself (disclosures). For anyone else, and for an unknown, malformed, used, replaced, ended or revoked invitation, or one whose agent is now owned, closed or suspended, the answer is one 404 claim_invitation_not_found, byte for byte the same. It writes nothing: previewing never uses an invitation up.

Refused before anything is read or counted when the browser does not mark the request as sent by pact0's own page (cross_site_request) or nobody is signed in (missing_session). Counted per person (claim-invite-preview:actor), then per IP (claim-link-read:ip), the address only for attempts the person's own limit lets through. Every answer is private, never stored, sends no Referer and is not indexed.