A verifiable booking record: two independent proofs an AI agent can check on the host's own domain

When an AI agent shows someone a price for a stay, that price is only worth acting on if the agent can be sure of two things: that the offer really came from the host, unchanged — and that it knows how the offer was delivered. Today HemmaBo has shipped the piece that makes both checkable: the VRP receipt.

The VRP receipt is a verifiable booking record. It carries two independent, separately signed proofs, and anyone can verify both against the host's own domain — without trusting HemmaBo.

Two proofs, one record

• The offer. The host's real price, dates and availability, signed on the host's own domain. This is the same standalone-verifiable signed stay offer the Vacation Rental Protocol has always produced.
• The delivery. A second, separately signed statement from the host's own domain: that this exact offer was served in response to an AI agent's request, at a specific time. It is the host attesting to the interaction — not something anyone else can fake.

Both are signed with the host's own key, published on the host's own domain. An agent — or anyone — fetches the host's public keys and checks the signatures. Alter a single byte and verification fails. We published this with an open verifier and a set of conformance examples anyone can run, so an independent implementer can reproduce the exact result and confirm it for themselves.

Why two proofs matter

The first proof answers "is this really the host's offer?" The second answers "and is this the offer the agent was actually shown?" Together they turn a quoted price into a record that can be checked after the fact — which matters the day a booking is questioned, a price is disputed, or an agent's claim needs to be confirmed against what the host actually served.

The record is deliberately simple: a flat list of proofs. A new kind of proof — a payment confirmation, a delivery attestation — is just a new entry in the list. There is no central body that approves what goes in, and no operator who becomes the keeper of the record. As agent-driven commerce adds new layers, they slot in beside the host's offer rather than above it.

And the offer never depends on the record. A VRP signed stay offer still verifies standalone from the host's own domain. The receipt adds provenance; it is never approval, a score, or a condition for a stay to be real.

What this is — and isn't

This is live today on the first host's own domain, and it is published as an open standard — free to implement, with an explicit patent grant on the reference code — at vacationrentalprotocol.com. HemmaBo built and runs the reference implementation. We are not claiming industry-wide adoption yet: that is earned when independent parties verify it for themselves, which is exactly why the verifier and the test examples are public.

The line we have held from the start still holds. HemmaBo is not a registry, not a certification company, not a scorer, accreditation body, OTA, or booking intermediary. The host's own domain is the source of truth. The receipt just makes that truth checkable.