The sale link is the key. Treat it like a password.
When you start a bill of sale, BoatHandoff saves the boat, seller and buyer details you type, inspection notes, signature images, and any photos you attach. On a local or self-hosted install those records sit in the host's data store (a JSON file in development, or Cloudflare D1 and R2 if you deploy that way). They are not sent to BoatHandoff as a company, because this app is the software you run.
The sale page uses an unguessable link. The seller and the buyer each get a separate sign link. Anyone with a link can open that part of the sale, so don't post the links in a public ad.
Paid kits are coming soon and Stripe is off. No card number is collected. A receipt can show the kit price, the tax for the buyer's province, and HST # 80698 3383 RT0001.
BoatHandoff does not post to Kijiji or Facebook, does not scrape listings, and does not sell the contents of a sale. The sample boat on the demo pages is fictional.