Let them argue with the facts.

Just say its name and ask. “Sent, is that number right?” Simple facts come back in about two seconds; trickier ones get an honest “give me a moment.”

If a question deserves real research, Sentinel raises its hand 🖐 and comes back with a proper answer when you call on it.

Two things: approve Sentinel when it requests the mic at your booked time, and give it a one-line introduction. Everything else is automatic.

Never. It speaks when summoned, and its only unprompted move is silently raising a hand. If someone talks over it, it stops and yields.

It verifies against sources and answers with a confidence level and a named source — “confirmed,” “likely, but I’d want a better source,” or “can’t verify that one.” It checks facts, not opinions, so your debate stays yours.

It never asserts arithmetic on its own — numbers are worked out in a sandbox before it speaks them.

Four general sources on every claim: Brave web search, Wikipedia, Wikidata, and the Google Fact Check index of published fact-checks. A claim is confirmed when two independent sources agree, or when one authoritative source settles it — the official record for its own facts.

Specialists by the kind of claim: the Bureau of Labor Statistics, FRED (the Federal Reserve’s data), the US Census, FBI crime data, CourtListener for court records, the Federal Register and eCFR for US rules, UK legislation, PubMed and OpenAlex for research papers, Google Books and the Internet Archive for what a book or an old newspaper actually said, and Wiktionary for words.

Coming soon: upload a PDF with your booking — the book or report your Space is about — and Sentinel searches it by page and cites the page.

Yes, and it’s built to admit it. Verdicts carry confidence levels, sources are named aloud, and if better evidence turns up mid-Space it raises its hand and corrects itself on air. Treat it as a very fast, very well-read participant — not an oracle.

Sentinel tries to join at your booked start time and keeps retrying the link every two minutes until it gets in — the start time doesn’t have to be the beginning of your Space. If the Space is delayed past your booked window, it will need to be re-booked.

It won’t vanish mid-sentence. Sentinel finishes its current answer, gives the room a scorecard, says goodbye, and leaves the stage.

Listeners can’t take the mic, but they can reply to your Space’s post, and Sentinel watches. “Someone in the audience is asking…” turns your listeners into participants.

They’re welcome to try — it makes for good radio. Sentinel treats everything said on stage as conversation to fact-check, never as instructions to follow.

Yes, and it never pretends otherwise. It’s disclosed in its bio, it introduces itself as an AI the first time it speaks, and it will cheerfully confirm it if asked.

Audio is never kept. The transcript is kept for 30 days so your report can be produced, then only the checked claims, their verdicts and their sources remain. A PDF uploaded with a booking (an option coming soon) is deleted an hour after the booked time ends. The full policy is under “The fine print” below.

Audio is never kept. Sentinel transcribes what is said as it streams and discards the sound. It does not record your Space.

The transcript is kept for 30 days. An attributed transcript (who said what) exists so your report and the receipt thread can be produced. Thirty days after the Space ends it is deleted, along with everything that quotes it.

What remains after that is the claim record: the claims Sentinel checked, its verdicts, the sources it used, and a summary of the session (when, how long, what it cost to run). No conversation survives beyond the claims themselves.

Things you send it. A PDF uploaded with a booking (an option coming soon) is read once and deleted an hour after the booked time ends. Links and images DM’d to Sentinel during a Space are looked at in the moment and not stored.

Your booking (the Space link, the handles, the settings and your payment details as Stripe reports them) is kept as the record of the sale.

The policy is enforced by the software, not by hand: a job runs at every start and every day and reduces old sessions to the claim record. If you want the transcript of your own Space removed sooner, write to hello@sentinel.build.

Who we are. Sentinel Fact-Checker, reachable at hello@sentinel.build.

What Sentinel is. An AI participant that joins the X Space you book, listens to what is said on stage, checks claims, and speaks when called on. It says it is an AI in its profile and the first time it speaks. Spaces are public; Sentinel is one more listener, and it is only ever in a Space its host booked it for.

What we collect and why. From you: the booking (Space link, host and co-host handles, the settings you choose, and when that option is on, a PDF) and, through Stripe, your email and payment. From the Space: the words spoken on stage, transcribed live, and the links, images and messages the host DMs to Sentinel. This is used only to run your session and produce your report and receipt thread.

Who else touches it. Payments are handled by Stripe; we never see your card number. To do its job Sentinel sends speech to a speech-recognition service, transcript passages and claims to AI-model and web-search providers, and its own replies to a voice service. None of them is allowed to use your data for anything but answering the request. We do not sell data, run advertising, or use analytics on this site; the site remembers a half-filled booking form only in your own browser.

How long. As set out in the retention policy above: audio never, transcripts 30 days, the claim record after that, a PDF for an hour past your booking.

Your rights. Transcripts of identifiable speakers are personal data. You can ask what we hold about you or your Space, ask for it to be corrected or deleted, or object to its processing, by writing to hello@sentinel.build; we answer within a month. If Sentinel checked something you said in someone else’s Space and you want it removed, the same applies.

Changes. If this page changes, the date at the bottom of it changes with it. This version: 21 September 2026.

Who these terms are with. Sentinel Fact-Checker (“we”), reachable at hello@sentinel.build, and you, the person booking.

What you are buying. A booking puts Sentinel in the X Space you name, from the start time you pick, for the hours you pay for, behaving the way you set on the form. The price is shown before you pay and charged in full at booking through Stripe.

What we need from you. Your Space must exist at the link you gave and be open at the booked time; you approve Sentinel when it asks for the mic and introduce it. Only the host and the co-hosts you name can send it clips. You are responsible for your Space and for following X’s rules in it.

If the Space starts late or never opens. Sentinel keeps trying to join every two minutes until your booked window ends. If your Space opens late inside the window, you get the time that is left. If it never opens, or Sentinel could not get in for a reason on our side, the booking is credited or refunded in full. A Space that runs past its booked window needs a new booking; Sentinel finishes what it is saying, gives the scorecard and leaves when the time is up.

Cancelling. You can cancel for a full refund up to 24 hours before the start time. After that the booking is used or forfeited, except where the failure was ours.

What Sentinel is and is not. It is an AI and says so. It checks facts against sources and states how confident it is; it can still be wrong, and it does not give medical, legal, financial or any other professional advice. Nothing it says is a statement by us about any person. You and your listeners decide what to do with it.

Fair use. Do not book Sentinel to harass, defame or deceive anyone, to impersonate a person, or to break X’s rules; we may end a session and refuse future bookings if that happens, without refund. We may also refuse or refund any booking we cannot serve, for example if X blocks the account Sentinel uses.

Liability. Our liability to you for anything arising from a booking is limited to the amount you paid for it. Nothing here limits liability that cannot be limited by law.

Data. How we handle what is said in your Space is set out in the privacy and retention notes above, which form part of these terms.

Changes. We may update these terms; the version in force is the one shown here when you book. This version: 21 September 2026.