If your properties run on Guesty, this page is the honest technical answer to "how would that actually work," not a sales page pretending the details don't matter.
What Guesty's API actually exposes
Guesty's Open API is REST-based, with requests sent to open-api.guesty.com/v1. Authentication is OAuth2: you exchange a Client ID and Client Secret, generated from your Guesty dashboard under Integrations, for an access token that lasts 24 hours, then send it as a Bearer token on every request. Everything is JSON over HTTPS.
One detail worth knowing before you build against it: Guesty allows up to five access tokens per API key within a 24-hour period. That's not a lot. An integration that requests a fresh token on every call will burn through its quota fast; the correct pattern is to cache the token and reuse it until it actually expires, which the response headers make easy to track (ratelimit-remaining, expires_in). It's a small thing, but it's the kind of detail that separates an integration that works in testing from one that holds up in production.
The endpoint families are Listings, Reservations, Guests, Tasks, and Webhooks, all under the /v1/ path.
What a reservation record actually contains
Guesty's reservation data is detailed enough to do more than confirm dates. Alongside the basics (confirmation code, listing, check-in and check-out, guest count) it carries a full money object: total paid, balance due, and whether the reservation is fully paid. It also records where the booking came from (source and secondarySource, meaning the actual channel: Airbnb, Booking.com, direct) and whether the guest is a returning one.
The balance-due field matters more than it looks. A guest asking "how much do I still owe" is a question the agent can answer accurately from real data, not a guess, and it's exactly the kind of question that piles up in an inbox overnight.
How the concierge agent uses this
The pattern is the same one behind the AI Guest Concierge: a guest message triggers an agent with tools, not a script. Mapped onto Guesty specifically, that looks like this.
Check Guesty availability lets the agent answer a date-range question against real inventory. Look up booking & balance is what turns "what do I owe" or "is my booking confirmed" into an accurate answer instead of "let me check and get back to you." Escalate to the team is the tool that matters most: anything involving money changing hands, an exception, or genuine judgment goes to a person.
What a guest conversation actually looks like
Hi, can you tell me how much we still owe for our stay next month?
Your booking shows a remaining balance, due before arrival; the exact figure is on your confirmation. I can't set up a custom payment plan myself, so I've let the team know you'd like to discuss one.
Illustrative example, not a real guest conversation.
Where a human still needs to be in the loop
Payments, refunds, cancellation exceptions, and anything involving a returning guest's history are decisions for a person with the authority and context to make them, not an agent following a tool call. The escalation path isn't a fallback for edge cases the agent failed on; it's designed in from the first version, the same way it is for every PMS this system supports.
What this page is, and isn't. This describes Guesty's public API and the integration architecture Attilus AI builds against it. It is not a claim that this is running live for a paying Guesty client today; the concierge pattern is a tested demo, documented honestly as that on the About page. A client build swaps the demo's tools for your property's real Guesty account and your real team's inbox.
The technical details above (base URL, authentication flow, token limits, reservation fields) are drawn directly from Guesty's own developer documentation, not from undisclosed internals.
What a property needs to get started
A Guesty account with API access enabled (this requires admin permissions on the account), a Client ID and Secret generated under Integrations → API & Webhooks, and confirmation of which guest channels you want answered. The rest gets shaped on the intro call around how your operation actually runs.
Technical details in this page are drawn from Guesty's public developer documentation at open-api-docs.guesty.com. See also the WebHotelier and Hostaway integration breakdowns. Guesty is a product of its respective owner; Attilus AI is not affiliated with Guesty.